dtvtransitioninfo.blogspot.com Information on how to cope with the transition to DTV

Is there a problem at ftp://hazards.cr.usg= s.gov/cnss/cnss_14.fing (All NEIC Events) I haven’t been able to get a update for more = than 6 hours. Is the server down?

Gary Lindgren

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

650-326-0655<= /span>

www.blue-eagle-technologies.com &nbs= p; Check out Lastest Seismometer = Reading

cymonsplace.blogspot.com =

dtvtransitioninfo.blogspot.com = ; Information on how to cope with the transition = to DTV

Subject: Baffin bay earthquake - Greenland From: jonfr@......... Date: Wed, 8 Jul 2009 02:15:22 -0000 (UTC) Hi all The earthquake near Greenland is a rare one, and quite intresting at that. I did cleary record it in Iceland on my geophones, however my lehman sensor does not work so nothing was recored there. I don't have a clear size, but USGS says the size is Mw6.1 at the depth of 10 km. More information about older events in that area. http://earthquakescanada.nrcan.gc.ca/histor/20th-eme/1933baffin-eng.php http://en.wikipedia.org/wiki/1933_Baffin_Bay_earthquake Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Another unreported earthquake From: "tchannel" tchannel@............ Date: Tue, 7 Jul 2009 21:01:19 -0600 Hi Folks,=20 At about 19:19:00 utc we recorded a large signal, As of yet, this has = not been reported by the USGS site.=20 Here is what I know, All three of my sensors recorded it, big time..... I have a new sensor in test which should respond to a North or South = event. This machine showed a big signature, so perhaps it came from N, = or S. Earthquake which happen in Idaho are sometimes not reported by the USGS = for one to three days after the earthquake. This may be the reason it = has not been published yet. Other states like Nevada or Utah have no such delays. I would welcome your opinion. If anyone recorded it. My guess is a 3 = or 4m, in Idaho or close to. I can not see a clear "S" so I can't = determined the degrees. I see several helicorder in Idaho and = Montana got it, but no identification yet. The 6.1 in Baffin Bay was = too far away for this signal. Thanks Ted

Hi Folks,

At about 19:19:00 utc we recorded a = large=20 signal, As of yet, this has not been reported by the USGS=20 site.

Here is what I know, All three of = my sensors=20 recorded it, big time.....

I have a new sensor in test which = should respond to=20 a North or South event. This machine showed a big signature, so = perhaps it=20 came from N, or S.

Earthquake which happen in Idaho are = sometimes not=20 reported by the USGS for one to three days after the = earthquake. =20 This may be the reason it has not been published yet.

Other states like Nevada or Utah have = no such=20 delays.

I would welcome your = opinion. If anyone=20 recorded it. My guess is a 3 or 4m, in Idaho or close=20 to. I can not see a clear "S" so I can't determined the = degrees. I see several helicorder in Idaho and = Montana=20 got it, but no identification yet. The 6.1 in Baffin Bay was = too far=20 away for this signal.

Thanks Ted

Subject: Re: Another unreported earthquake From: Thomas Dick dickthomas01@............. Date: Tue, 07 Jul 2009 22:44:24 -0500 tchannel wrote: > Hi Folks, > > At about 19:19:00 utc we recorded a large signal, As of yet, this has > not been reported by the USGS site. > > Here is what I know, All three of my sensors recorded it, big time..... > > I have a new sensor in test which should respond to a North or South > event. This machine showed a big signature, so perhaps it came from > N, or S. > > Earthquake which happen in Idaho are sometimes not reported by the > USGS for one to three days after the earthquake. This may be the > reason it has not been published yet. > > Other states like Nevada or Utah have no such delays. > > I would welcome your opinion. If anyone recorded it. My guess is a > 3 or 4m, in Idaho or close to. I can not see a clear "S" so I can't > determined the degrees. I see several helicorder in Idaho and > Montana got it, but no identification yet. The 6.1 in Baffin Bay was > too far away for this signal. > > Thanks Ted > wouldn't that be the time of arrival for P wave for the Baffin Bay quake? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Another unreported earthquake From: "tchannel" tchannel@............ Date: Tue, 7 Jul 2009 22:08:29 -0600 Hi Thomas Dick and all, I think you are right. I processed it using Baffin Bay and the P lined up perfectly. If this is the case, I was wrong to think it was closer, like here in Idaho. The signal looked too large for a 6.1 4100km away. I am very surprised. Thanks for you help. Ted ----- Original Message ----- From: "Thomas Dick" To: Sent: Tuesday, July 07, 2009 9:44 PM Subject: Re: Another unreported earthquake > tchannel wrote: >> Hi Folks, >> At about 19:19:00 utc we recorded a large signal, As of yet, this has >> not been reported by the USGS site. Here is what I know, All three of my >> sensors recorded it, big time..... >> I have a new sensor in test which should respond to a North or South >> event. This machine showed a big signature, so perhaps it came from N, >> or S. >> Earthquake which happen in Idaho are sometimes not reported by the USGS >> for one to three days after the earthquake. This may be the reason it >> has not been published yet. >> Other states like Nevada or Utah have no such delays. >> I would welcome your opinion. If anyone recorded it. My guess is a 3 >> or 4m, in Idaho or close to. I can not see a clear "S" so I can't >> determined the degrees. I see several helicorder in Idaho and Montana >> got it, but no identification yet. The 6.1 in Baffin Bay was too far >> away for this signal. >> Thanks Ted >> > wouldn't that be the time of arrival for P wave for the Baffin Bay quake? > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Recent EQ From: "Geoffrey" gmvoeth@........... Date: Tue, 7 Jul 2009 21:42:54 -0700 Hello PSN; Today I received a surface wave only since it was the only part that rose above the noise to trigger the recording. I have heard through other channels ( family ) that there may have been an EQ located near Richmond Virginia but not at all sure they are telling me a truth. If it made such a surface wave ID expect damage possibly in that area. But not sure about anything till someone says it in the news or ??? Possible Surface Waves Received at GVA L_19:34:54.9_2009JUL07_UTC ?? NOT CERTAIN ABOUT THIS BEING ANYTHING ?? Regards; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Another unreported earthquake From: Robert Thomasson rlthomasson@......... Date: Wed, 8 Jul 2009 07:45:18 +0300 Ted, Yes, I initially thought the same thing here in Reno, that it was too strong of a signal to be from Baffin Bay, but it looks like it was. Very interesting. I have two horizontal sensors, both recently installed and still in preliminary states of adjustment. I got what I think is a nice pattern on the NS sensor and nothing at all on the EW sensor. Don't know if the lack of anything from the EW sensor is due to the poor initial state of tune, but I suspect so. Bob On Wed, Jul 8, 2009 at 7:08 AM, tchannel wrote: > Hi Thomas Dick and all, I think you are right. I processed it using > Baffin Bay and the P lined up perfectly. > If this is the case, I was wrong to think it was closer, like here in > Idaho. The signal looked too large for a 6.1 4100km away. > I am very surprised. > Thanks for you help. > Ted > > > > > > ----- Original Message ----- From: "Thomas Dick" < > dickthomas01@.............> > To: > Sent: Tuesday, July 07, 2009 9:44 PM > Subject: Re: Another unreported earthquake > > > > tchannel wrote: >> >>> Hi Folks, >>> At about 19:19:00 utc we recorded a large signal, As of yet, this has >>> not been reported by the USGS site. Here is what I know, All three of my >>> sensors recorded it, big time..... >>> I have a new sensor in test which should respond to a North or South >>> event. This machine showed a big signature, so perhaps it came from N, or >>> S. >>> Earthquake which happen in Idaho are sometimes not reported by the USGS >>> for one to three days after the earthquake. This may be the reason it has >>> not been published yet. >>> Other states like Nevada or Utah have no such delays. >>> I would welcome your opinion. If anyone recorded it. My guess is a 3 >>> or 4m, in Idaho or close to. I can not see a clear "S" so I can't >>> determined the degrees. I see several helicorder in Idaho and Montana >>> got it, but no identification yet. The 6.1 in Baffin Bay was too far away >>> for this signal. >>> Thanks Ted >>> >>> wouldn't that be the time of arrival for P wave for the Baffin Bay >> quake? >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > Ted,

Yes, I initially thought the same thing here in Reno, that it w= as too strong of a signal to be from Baffin Bay, but it looks like it was.= =A0=A0 Very interesting. I have two horizontal sensors, both recently insta= lled and still in preliminary states of adjustment.=A0 I got what I think i= s a nice pattern on the NS sensor and nothing at all on the EW sensor.=A0 D= on't=A0 know if the lack of anything from the EW sensor is due to the p= oor initial state of tune, but I suspect so.

Bob

On Wed, Jul 8, 2009 at 7:08 AM, t= channel <tcha= nnel@............> wrote:

Hi Thomas Dick and all, =A0 =A0I think you are right. =A0 I processed it us= ing Baffin Bay and the P lined up perfectly.
If this is the case, I was wrong to think it was closer, like here in Idaho= .. The signal looked too large for a 6.1 4100km away.
I am very surprised.
Thanks for you help.
Ted

----- Original Message ----- From: "Thomas Dick" <dickthomas01@........... com>
To: <psn-l@web= tronics.com>
Sent: Tuesday, July 07, 2009 9:44 PM
Subject: Re: Another unreported earthquake

tchannel wrote:

Hi Folks,
=A0At about 19:19:00 utc we recorded a large signal, =A0As of yet, this has= not been reported by the USGS site. Here is what I know, =A0All three of m= y sensors recorded it, big time.....
=A0I have a new sensor in test which should respond to a North or South eve= nt. =A0This machine showed a big signature, so perhaps it came from N, or S= ..
=A0Earthquake which happen in Idaho are sometimes not reported by the USGS = for one to three days after the earthquake. =A0 This may be the reason it h= as not been published yet.
=A0Other states like Nevada or Utah have no such delays.
=A0I would welcome your opinion. =A0 If anyone recorded it. =A0 My guess is= a 3 or 4m, in Idaho or close to. =A0I can not see a clear "S" = =A0so I can't determined the degrees. =A0 =A0 I see several helicorder = in Idaho and Montana got it, but no identification yet. =A0 The 6.1 in Baff= in Bay was too far away for this signal.
=A0Thanks Ted

wouldn't that be the time of arrival for P wave for the Baffin Bay quak= e?
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the messa= ge (first line only): unsubscribe
See h= ttp://www.seismicnet.com/maillist.html for more information.

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the messa= ge (first line only): unsubscribe
See h= ttp://www.seismicnet.com/maillist.html for more information.

Subject: RE: Another unreported earthquake From: "Gary Lindgren" gel@................. Date: Tue, 7 Jul 2009 21:56:22 -0700 Hi Ted, I got here too in Palo Alto, the problem is that the USGS server must be down. There are no new updates for 12 to 13 hours. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of tchannel Sent: Tuesday, July 07, 2009 8:01 PM To: psn Subject: Another unreported earthquake Hi Folks, At about 19:19:00 utc we recorded a large signal, As of yet, this has not been reported by the USGS site. Here is what I know, All three of my sensors recorded it, big time..... I have a new sensor in test which should respond to a North or South event. This machine showed a big signature, so perhaps it came from N, or S. Earthquake which happen in Idaho are sometimes not reported by the USGS for one to three days after the earthquake. This may be the reason it has not been published yet. Other states like Nevada or Utah have no such delays. I would welcome your opinion. If anyone recorded it. My guess is a 3 or 4m, in Idaho or close to. I can not see a clear "S" so I can't determined the degrees. I see several helicorder in Idaho and Montana got it, but no identification yet. The 6.1 in Baffin Bay was too far away for this signal. Thanks Ted

Hi Ted,

I got here too in Palo Alto, the problem is that the USGS = server must be down. There are no new updates for 12 to 13 = hours.

Gary

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of tchannel
Sent: Tuesday, July 07, 2009 8:01 PM
To: psn
Subject: Another unreported earthquake

Hi Folks,

At about 19:19:00 utc we recorded a large signal, As of yet, this has = not been reported by the USGS site.

Here is what I know, All three of my sensors recorded it, big = time.....

I have a new sensor in test which should respond to a North or South = event. This machine showed a big signature, so perhaps it came from N, or = S.

Earthquake which happen in Idaho are sometimes not reported by the USGS for one to = three days after the earthquake. This may be the reason it has not = been published yet.

Other states like Nevada or Utah have no such delays.

I would welcome your opinion. If anyone recorded = it. My guess is a 3 or 4m, in Idaho or close to. I can not see a = clear "S" so I can't determined the degrees. I see several helicorder in Idaho and Montana got it, but no identification yet. The 6.1 in Baffin Bay was too far away = for this signal.

Thanks Ted

Subject: RE: Another unreported earthquake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 08 Jul 2009 07:00:39 +0000 Hi all According to EMSC, the Baffin bay earthquake was Mw6.0 at the depth of 10 km. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D133253 Regards. J=F3n Fr=EDmann. On =FEri, 2009-07-07 at 21:56 -0700, Gary Lindgren wrote: > Hi Ted, >=20 > I got here too in Palo Alto, the problem is that the USGS server must > be down. There are no new updates for 12 to 13 hours. >=20 > Gary >=20 > =20 >=20 > =20 >=20 > =20 >=20 > =20 >=20 > =20 >=20 > From:psn-l-request@.............. > [mailto:psn-l-request@............... On Behalf Of tchannel > Sent: Tuesday, July 07, 2009 8:01 PM > To: psn > Subject: Another unreported earthquake >=20 >=20 > =20 >=20 > Hi Folks,=20 >=20 >=20 > =20 >=20 >=20 > At about 19:19:00 utc we recorded a large signal, As of yet, this has > not been reported by the USGS site.=20 >=20 >=20 > =20 >=20 >=20 > Here is what I know, All three of my sensors recorded it, big > time..... >=20 >=20 > =20 >=20 >=20 > I have a new sensor in test which should respond to a North or South > event. This machine showed a big signature, so perhaps it came from > N, or S. >=20 >=20 > =20 >=20 >=20 > Earthquake which happen in Idaho are sometimes not reported by the > USGS for one to three days after the earthquake. This may be the > reason it has not been published yet. >=20 >=20 > =20 >=20 >=20 > Other states like Nevada or Utah have no such delays. >=20 >=20 > =20 >=20 >=20 > I would welcome your opinion. If anyone recorded it. My guess is a > 3 or 4m, in Idaho or close to. I can not see a clear "S" so I can't > determined the degrees. I see several helicorder in Idaho and > Montana got it, but no identification yet. The 6.1 in Baffin Bay was > too far away for this signal. >=20 >=20 > =20 >=20 >=20 > Thanks Ted >=20 >=20 > =20 >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Another unreported earthquake From: Thomas Dick dickthomas01@............. Date: Wed, 08 Jul 2009 06:59:25 -0500 Gary Lindgren wrote: > > Hi Ted, > > I got here too in Palo Alto, the problem is that the USGS server must > be down. There are no new updates for 12 to 13 hours. > > Gary > I think I saw your original post about this. I used the USGS site to input data almost immediately (within two hours) of the visual on my monitor. Could this be some sort of local problem? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Another unreported earthquake From: Thomas Dick dickthomas01@............. Date: Wed, 08 Jul 2009 07:02:01 -0500 Jón Frímann wrote: > Hi all > > According to EMSC, the Baffin bay earthquake was Mw6.0 at the depth of > 10 km. > > Yes, and from the posts on PSN, the surface waves were very pronounced ... particularly in the 40 degree distance. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Regarding the USGS ftp server issue From: "Gary Lindgren" gel@................. Date: Wed, 8 Jul 2009 15:00:14 -0700 I just received this response from USGS: Yes. We were just told that there was a problem with the ftp site. And they do not know when it will be fixed. Madeleine Zirbes USGS NEIC Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com Check out Lastest Seismometer Reading cymonsplace.blogspot.com dtvtransitioninfo.blogspot.com Information on how to cope with the transition to DTV

I just received this response from = USGS:

Yes.

We = were just told that there was a problem with the ftp site.
And = they do not know when it will be fixed.

Madeleine Zirbes
USGS NEIC

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

650-326-0655<= /span>

www.blue-eagle-technologies.com &nbs= p; Check out Lastest Seismometer = Reading

cymonsplace.blogspot.com =

dtvtransitioninfo.blogspot.com = ; Information on how to cope with the transition = to DTV

Subject: Re: Regarding the USGS ftp server issue From: Larry Cochrane lcochrane@.............. Date: Wed, 08 Jul 2009 18:00:46 -0700 Thanks for the update Gary. -Larry Gary Lindgren wrote: > I just received this response from USGS: > > > > Yes. > > We were just told that there was a problem with the ftp site. > And they do not know when it will be fixed. > > Madeleine Zirbes > USGS NEIC > > > > > > > > > > > > > > Gary Lindgren > > 585 Lincoln Ave > > Palo Alto CA 94301 > > > > 650-326-0655 > > > > www.blue-eagle-technologies.com > Check out Lastest Seismometer Reading > > cymonsplace.blogspot.com > > dtvtransitioninfo.blogspot.com > Information on how to cope with the transition to DTV > > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Lose weight FAST! From: lcochrane@.............. Date: Thu, 9 Jul 2009 14:45:19 +0200 Get your Free trial today! Claim your risk free trial of Acai Berry now =20 Press a button =20 best regards Venita=20 Mcwilliams =20 =20

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<= A=20 href=3D"http://ubk253.aiwgqrjo.cn/">Press a button

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Subject: Short period spring vertical lower pivot question From: meredith lamb paleoartifact@......... Date: Mon, 13 Jul 2009 13:05:37 -0600 Hi all, BACKGROUND PIVOT: Chris Chapman's newer horizontal designs with his lower pivot being a boom end flat that is pivoting on a mast mounted ball bearing seems to be a very ideal, reliable and much more stable "standard pivot" for those of us endeavoring to make a commonly used home brew horizontal seismometer. It was studied in 2008 by him, Charles Patton and Brett Nordgren and briefly described by the web paper: http://www.myeclectric.info/SeismoPivots/seismopivots.htm and had many other PSN description emails in that time period. The question that comes up from all this is whether such a lower pivot/s could be ~ reliably used in a home brew short period vertical spring seismometer? I note no reference to such a trial; but that doesn't exclude that someones hasn't already experimented with such? This excludes known boom mounted balls on a mast flat. The size/weight of the seismometer mass in mind is similar to that of the AS1. I would also assume that it is likely necessary to have any such balls mounted on the side of a mechanical support/s to fix the spring opposition. It would necessitate two such pivots for maintaining vertical positional reliability...i.e.; the "boom" would need to be "T" shaped to constrain its otherwise undesirable lateral movement with only one pivot. Meredith Lamb

Hi all,

=A0

BACKGROUND PIVOT:=A0 Chris Chapman's newer horizontal designs with= his lower pivot being a boom end flat that is=A0pivoting on a mast mounted=

ball bearing seems to be a very ideal, reliable and much more stable &= quot;standard pivot" for those of us endeavoring=A0=A0to make a common= ly used=A0home

brew horizontal seismometer.=A0 It was studied in 2008 by him, Charles= Patton and Brett Nordgren and=A0briefly described by the web paper:=A0 http://w= ww.myeclectric.info/SeismoPivots/seismopivots.htm=A0=A0 and had many ot= her PSN description emails in that time period.

=A0

The question that comes up from all this is whether such a lower pivot= /s could be=A0~ reliably used=A0in a home brew short period vertical

spring seismometer?=A0 I note no reference to such a trial; but that d= oesn't exclude that someones hasn't already experimented=A0with=A0s= uch?

This excludes known boom mounted balls on a mast flat.=A0 The size/wei= ght of the seismometer mass in mind is similar to that of the AS1.

=A0

I would also=A0assume that it=A0is likely=A0necessary to have any such= balls mounted on the side of a mechanical support/s to=A0fix the spring op= position.

=A0

It would necessitate two such pivots for=A0maintaining vertical positi= onal reliability...i.e.; the "boom"=A0would need to be "T&qu= ot; shaped to constrain

its otherwise undesirable lateral movement with only one pivot.=A0

=A0

Meredith Lamb

=A0

Subject: live the active liefestyle you always wanted with Acai Berry. From: lcochrane@.............. Date: Mon, 13 Jul 2009 21:24:16 +0100 If you experience difficulty viewing=20 this message, you can view it in your browser. =20 =20 =20 eNews July=20 2009 =20 =20 =20 =20 =20 Acai Berry Trial is available now!please visit =20 =20 =20 =20 Update your details | Unsubscribe or edit=20 optionsPlease forward this eNewsletter to a=20 friends

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Subject: Re: Short period spring vertical lower pivot question From: Robert Thomasson rlthomasson@......... Date: Mon, 13 Jul 2009 22:36:59 +0300 Meredith, there was an extra "r" typo in your myelectric.info link. The corrected link is below (I think) http://www.myeclectic.info/SeismoPivots/seismopivots.htm On Mon, Jul 13, 2009 at 10:05 PM, meredith lamb wrote: > Hi all, > > BACKGROUND PIVOT: Chris Chapman's newer horizontal designs with his lower > pivot being a boom end flat that is pivoting on a mast mounted > ball bearing seems to be a very ideal, reliable and much more stable > "standard pivot" for those of us endeavoring to make a commonly used home > brew horizontal seismometer. It was studied in 2008 by him, Charles Patton > and Brett Nordgren and briefly described by the web paper: > http://www.myeclectric.info/SeismoPivots/seismopivots.htm and had many > other PSN description emails in that time period. > > The question that comes up from all this is whether such a lower pivot/s > could be ~ reliably used in a home brew short period vertical > spring seismometer? I note no reference to such a trial; but that doesn't > exclude that someones hasn't already experimented with such? > This excludes known boom mounted balls on a mast flat. The size/weight of > the seismometer mass in mind is similar to that of the AS1. > > I would also assume that it is likely necessary to have any such balls > mounted on the side of a mechanical support/s to fix the spring opposition. > > It would necessitate two such pivots for maintaining vertical positional > reliability...i.e.; the "boom" would need to be "T" shaped to constrain > its otherwise undesirable lateral movement with only one pivot. > > Meredith Lamb > > > > > > > > > > > Meredith, there was an extra "r" typo in your myelectric.info link.=A0 The corrected=A0 link is below= (I think)

http://www.myeclectic.info/SeismoPivots/seismopivots.htm

On Mon, Jul 13, 2009 at 10:05 PM, me= redith lamb <paleoartifact@.........> wrote:

Hi all,

=A0

BACKGROUND PIVOT:=A0 Chris Chapman's newer horizontal designs with= his lower pivot being a boom end flat that is=A0pivoting on a mast mounted=

ball bearing seems to be a very ideal, reliable and much more stable &= quot;standard pivot" for those of us endeavoring=A0=A0to make a common= ly used=A0home

brew horizontal seismometer.=A0 It was studied in 2008 by him, Charles= Patton and Brett Nordgren and=A0briefly described by the web paper:=A0 http://www.myeclectric.info/SeismoPivots/seismopivots.htm= =A0=A0 and had many other PSN description emails in that time period.

=A0

The question that comes up from all this is whether such a lower pivot= /s could be=A0~ reliably used=A0in a home brew short period vertical

spring seismometer?=A0 I note no reference to such a trial; but that d= oesn't exclude that someones hasn't already experimented=A0with=A0s= uch?

This excludes known boom mounted balls on a mast flat.=A0 The size/wei= ght of the seismometer mass in mind is similar to that of the AS1.

=A0

I would also=A0assume that it=A0is likely=A0necessary to have any such= balls mounted on the side of a mechanical support/s to=A0fix the spring op= position.

=A0

It would necessitate two such pivots for=A0maintaining vertical positi= onal reliability...i.e.; the "boom"=A0would need to be "T&qu= ot; shaped to constrain

its otherwise undesirable lateral movement with only one pivot.=A0
=A0

Meredith Lamb

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

Subject: Stay healthy with acaiberry From: lcochrane@.............. Date: Tue, 14 Jul 2009 05:06:21 +0900 Hollywoods fat burning secret is out. Look at this site http://www.jilaussfontrimm.com/?ttscgdmeq best regards Elma Strickland __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Short period spring vertical lower pivot question From: meredith lamb paleoartifact@......... Date: Mon, 13 Jul 2009 14:44:29 -0600 Hi Robert You're correct; my mistake. However, my IE browser here still won't go to such (?). It will; however, if one leaves out the "www", per linked below, then it seems to work reliably. http://myeclectic.info/SeismoPivots/seismopivots.htm Meredith Lamb On Mon, Jul 13, 2009 at 1:36 PM, Robert Thomasson wrote: > Meredith, there was an extra "r" typo in your myelectric.info link. The > corrected link is below (I think) > > http://www.myeclectic.info/SeismoPivots/seismopivots.htm > > > > > On Mon, Jul 13, 2009 at 10:05 PM, meredith lamb wrote: > >> Hi all, >> >> BACKGROUND PIVOT: Chris Chapman's newer horizontal designs with his lower >> pivot being a boom end flat that is pivoting on a mast mounted >> ball bearing seems to be a very ideal, reliable and much more stable >> "standard pivot" for those of us endeavoring to make a commonly used home >> brew horizontal seismometer. It was studied in 2008 by him, Charles >> Patton and Brett Nordgren and briefly described by the web paper: >> http://www.myeclectric.info/SeismoPivots/seismopivots.htm and had many >> other PSN description emails in that time period. >> >> The question that comes up from all this is whether such a lower pivot/s >> could be ~ reliably used in a home brew short period vertical >> spring seismometer? I note no reference to such a trial; but that doesn't >> exclude that someones hasn't already experimented with such? >> This excludes known boom mounted balls on a mast flat. The size/weight of >> the seismometer mass in mind is similar to that of the AS1. >> >> I would also assume that it is likely necessary to have any such balls >> mounted on the side of a mechanical support/s to fix the spring opposition. >> >> It would necessitate two such pivots for maintaining vertical positional >> reliability...i.e.; the "boom" would need to be "T" shaped to constrain >> its otherwise undesirable lateral movement with only one pivot. >> >> Meredith Lamb >> >> >> >> >> >> >> >> >> >> >> > >
Hi Robert

=A0

You're correct; my mistake.=A0 However,=A0my IE browser here still= won't=A0go to such (?). =A0=A0=A0=A0

=A0It will; however, if one leaves out the "www", per=A0link= ed below, then=A0it seems to work reliably.

=A0

http:= //myeclectic.info/SeismoPivots/seismopivots.htm

Meredith Lamb

On Mon, Jul 13, 2009 at 1:36 PM, Robert Thomasso= n <rlthomasso= n@.........> wrote:

Meredith, there was an extra &qu= ot;r" typo in your myelectric.info link.=A0 The corrected=A0 link is below (I think)
http://www.myeclectic.info/SeismoPivots/seismopivots.htm=

On Mon, Jul 13, 2009 at 10:05 PM, meredith lamb = <paleoartifact@.........> wrote:

Hi all,

=A0

BACKGROUND PIVOT:=A0 Chris Chapman's newer horizontal designs with= his lower pivot being a boom end flat that is=A0pivoting on a mast mounted=

ball bearing seems to be a very ideal, reliable and much more stable &= quot;standard pivot" for those of us endeavoring=A0=A0to make a common= ly used=A0home

brew horizontal seismometer.=A0 It was studied in 2008 by him, Charles= Patton and Brett Nordgren and=A0briefly described by the web paper:=A0 http://www.myeclectric.info/SeismoPivots/seismopivots.htm= =A0=A0 and had many other PSN description emails in that time period.

=A0

The question that comes up from all this is whether such a lower pivot= /s could be=A0~ reliably used=A0in a home brew short period vertical

spring seismometer?=A0 I note no reference to such a trial; but that d= oesn't exclude that someones hasn't already experimented=A0with=A0s= uch?

This excludes known boom mounted balls on a mast flat.=A0 The size/wei= ght of the seismometer mass in mind is similar to that of the AS1.

=A0

I would also=A0assume that it=A0is likely=A0necessary to have any such= balls mounted on the side of a mechanical support/s to=A0fix the spring op= position.

=A0

It would necessitate two such pivots for=A0maintaining vertical positi= onal reliability...i.e.; the "boom"=A0would need to be "T&qu= ot; shaped to constrain

its otherwise undesirable lateral movement with only one pivot.=A0
=A0

Meredith Lamb

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=
Subject: USGS ftp Sites From: Larry Cochrane lcochrane@.............. Date: Mon, 13 Jul 2009 18:20:50 -0700 Hi Everyone, It looks like the USGS FTP site ( ftp://hazards.cr.usgs.gov/cnss/cnss_14.fing ) is still not working. The procedure below can be used to import an event report into WinQuake. You will need to use this until the FTP site is working again or when I have time to work on WinQuake. 1. Make sure WinQuake is not running. 2. Download this file http://www.seismicnet.com/software/usgs_report.zip and unzip the file into your WinQuake root directory. 3. Open a DOS Box. Start / Run... menu items then type cmd at the prompt. 4. At the command prompt move to the WinQuake directory using the "cd" command. Example: "cd \winquake" without the quotes. 5. At the command prompt type "usgsrpt.bat". This should create a file called usgs.rpt. The report is from this URL http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/quakes_all.php 6. Start Winquake and open the Event Report dialog box. 7. Select "NEIC - Web" in the Type: list box. If you do not see this in the list go back to step 1. 8. Now press the "Load Report File" button and select the newly create usgs.rpt file. 9. When you Close the Report Open dialog box you should see events in the list that can be used to update your event files. New subject. Has anyone tried either WinSDR or WinQuake on Windows 7? Regards, Larry Cochrane Redwood City, PSN Gary Lindgren wrote: > Hello Larry, > > That USGS ftp site is still down, are you aware of any other sites with > earthquake data for all the world and that have format for Winquake. One > other question, are your programs OK with Windows 7? > > Thank you > > > > Gary Lindgren __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Short period spring vertical lower pivot question From: ChrisAtUpw@....... Date: Mon, 13 Jul 2009 22:51:25 EDT In a message dated 13/07/2009, paleoartifact@......... writes: Hi All, Both _http://www.myeclectic.info/SeismoPivots/seismopivots.htm _ (http://www.myeclectic.info/SeismoPivots/seismopivots.htm%20) and _http://myeclectic.info/SeismoPivots/seismopivots.htm_ (http://myeclectic.info/SeismoPivots/seismopivots.htm) both seem to work on my Internet Explorer BACKGROUND PIVOT: Chris Chapman's newer horizontal designs with his lower pivot being a boom end flat that is pivoting on a mast mounted ball bearing seems to be a very ideal, reliable and much more stable "standard pivot" for those of us endeavoring to make a commonly used home brew horizontal seismometer. It was studied in 2008 by him, Charles Patton and Brett Nordgren and briefly described by the web paper: See Lehman photo _http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_prototype.jpg_ (http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_prototype.jpg) This uses a 16 thou thick SS strip cut from a scalpel blade glued to the end of the arm, rolling on a 1/2" SS ball on the upright. This has a MUCH better stability than a ball rolling on a plane. Also note the 30 lb 7 core V SS fishing trace suspension, which prevents the arm from rotating about it's long axis. I tested this suspension OK for stable periods of up to 60 seconds. Note also that the frame level screws use a wavy washer and a locknut to prevent rotation as the frame expands or contracts when the temperature changes. This seemed to improve the long term drift stability quite a bit. SS dome nuts make a very good rolling contact on the lower ends of levelling screws. I find that 1/16" copper is preferable to Aluminum for the damping plate. Aluminum is slightly paramagnetic and the edges of an Al plate need to overlap the damping magnets at all times. If you don't do this, the arm will skate sideways to the stop if the edge of the Al plate comes close to the edges of the magnets. A square section coil is attached to the underside of the Al mounting block. This photo was taken before the sensor cable was installed along the arm. The question that comes up from all this is whether such a lower pivot/s could be ~ reliably used in a home brew short period vertical spring seismometer? I note no reference to such a trial; but that doesn't exclude that someones hasn't already experimented with such? This excludes known boom mounted balls on a mast flat. The size/weight of the seismometer mass in mind is similar to that of the AS1. This was effectively done with cylinders rolling on a plane with the EAI vertical seismometer, now discontinued. I still have a copy of the manual. You need to space the two balls fairly well apart on the upright to prevent them from slipping due to horizontal seismic motions. It is also desirable to design the arm so that there is no vertical force on the rolling contacts. You attach the spring just behind the centre of mass and the weight of the arm is balanced by the weight of the mass about this attachment point. Alternatively, you can fit an I bar across the vertical and make a C fitting to go around it, attached to the end of the arm. You can then use two piano wires under tension from the ends of the C to the enclosed I. I would also assume that it is likely necessary to have any such balls mounted on the side of a mechanical support/s to fix the spring opposition. It would necessitate two such pivots for maintaining vertical positional reliability...i.e.; the "boom" would need to be "T" shaped to constrain its otherwise undesirable lateral movement with only one pivot. Regards, Chris Chapman
In a message dated 13/07/2009, paleoartifact@......... writes:

Hi All,

    Both http://www.myeclectic.info/SeismoPivots/seismopivots.htm= and http://myecl= ectic.info/SeismoPivots/seismopivots.htm both seem to work on my Internet Explorer

BACKGROUND PIVOT: Chris Chapman's newer horizontal designs wi= th his lower pivot being a boom end flat that is pivoting on a mast mounte= d ball bearing seems to be a very ideal, reliable and much more stable "standar= d pivot" for those of us endeavoring  to make a commonly used home brew horizontal seismometer. It was studied in 2008= by him, Charles Patton and Brett Nordgren and briefly described by the= web paper:

    See Lehman photo http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_prototy= pe.jpg

    This uses a 16 thou thick SS strip cut from= a scalpel blade glued to the end of the arm, rolling on a 1/2" SS ball= on the upright. This has a MUCH better stability than a ball rolling on a plane.

    Also note the 30 lb 7 core V SS fishing trace= suspension, which prevents the arm from rotating about it's long axis. I= tested this suspension OK for stable periods of up to 60 seconds. Note also that= the frame level screws use a wavy washer and a locknut to prevent rotatio= n as the frame expands or contracts when the temperature changes. This seemed= to improve the long term drift stability quite a bit. SS dome nuts make a ver= y good rolling contact on the lower ends of levelling screws.

    I find that 1/16" copper is preferable to Alu= minum for the damping plate. Aluminum is slightly paramagnetic and the edges of= an Al plate need to overlap the damping magnets at all times. If you don't do th= is, the arm will skate sideways to the stop if the edge of the Al plate comes= close to the edges of the magnets.

    A square section coil is attached to the unde= rside of the Al mounting block. This photo was taken before the sensor cable was= installed along the arm.

The question that comes up from all this is whether such a lowe= r pivot/s could be ~ reliably used in a home brew short peri= od vertical spring seismometer? I note no reference to such a tri= al; but that doesn't exclude that someones hasn't already experimented with such?

This excludes known boom mounted balls on a mast flat. Th= e size/weight of the seismometer mass in mind is similar to that of th= e AS1.

    This was effectively done with cyl= inders rolling on a plane with the EAI vertical seismometer, now discontinued. I= still have a copy of the manual.

    You need to space the two balls fa= irly well apart on the upright to prevent them from slipping due to horizo= ntal seismic motions. It is also desirable to design the arm so that there is= no vertical force on the rolling contacts. You attach the spring just= behind the centre of mass and the weight of the arm is balanced by the weight of= the mass about this attachment point.

    Alternatively, you can fit an I ba= r across the vertical and make a C fitting to go around it, attached to the end of= the arm. You can then use two piano wires under tension from the ends of the= C to the enclosed I.

I would also assume that it is likely necessary to= have any such balls mounted on the side of a mechanical support/s to f= ix the spring opposition.

It would necessitate two such pivots for maintaining vertica= l positional reliability...i.e.; the "boom" would need to be "T" sh= aped to constrain its otherwise undesirable lateral movement with only one= pivot.

    Regards,

    Chris Chapman
Subject: Re: Short period spring vertical lower pivot question From: meredith lamb paleoartifact@......... Date: Tue, 14 Jul 2009 00:43:43 -0600 Hi Chris and all, On Mon, Jul 13, 2009 at 8:51 PM, wrote: > In a message dated 13/07/2009, paleoartifact@......... writes: > > Hi All, > > Both http://www.myeclectic.info/SeismoPivots/seismopivots.htm > and > http://myeclectic.info/SeismoPivots/seismopivots.htm both seem to work on > my Internet Explorer > > BACKGROUND PIVOT: Chris Chapman's newer horizontal designs with his lower > pivot being a boom end flat that is pivoting on a mast mounted ball bearing > seems to be a very ideal, reliable and much more stable "standard pivot" for > those of us endeavoring to make a commonly used home brew horizontal > seismometer. It was studied in 2008 by him, Charles Patton and Brett > Nordgren and briefly described by the web paper: > > See Lehman photo > http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_prototype.jpg > *Chris, beautiful work on the seismo! I agree it apparently has several significant improvements over that of the SEP seismometer sold there in the United Kingdom and elsewhere. I wanted to try the pivot last year but didn't get around to a trial. Perhaps (?), this year I might be able to do so...with a "test setup" assembly I'am planning and constructing. *For those readers interested in the SEP seismometer, and, if you have a broadband connection; Youtube has a good recent video of the "UK School Seismology: seismometer assembly" film produced by the British Geological Survey. Go to Youtube and in the search box, enter in the title above. The BGS has a Youtube "channel" (index) with other interesting videos also. The SEP uses upper suspension and lower boom, crossed rods pivots. > This uses a 16 thou thick SS strip cut from a scalpel blade glued to > the end of the arm, rolling on a 1/2" SS ball on the upright. This has a > MUCH better stability than a ball rolling on a plane. > Also note the 30 lb 7 core V SS fishing trace suspension, which > prevents the arm from rotating about it's long axis. I tested this > suspension OK for stable periods of up to 60 seconds. Note also that the > frame level screws use a wavy washer and a locknut to prevent rotation as > the frame expands or contracts when the temperature changes. This seemed to > improve the long term drift stability quite a bit. SS dome nuts make a very > good rolling contact on the lower ends of levelling screws. > I find that 1/16" copper is preferable to Aluminum for the damping > plate. Aluminum is slightly paramagnetic and the edges of an Al plate need > to overlap the damping magnets at all times. If you don't do this, the arm > will skate sideways to the stop if the edge of the Al plate comes close to > the edges of the magnets. > > A square section coil is attached to the underside of the Al mounting > block. This photo was taken before the sensor cable was installed along the > arm. > > The question that comes up from all this is whether such a lower pivot/s >>> could be ~ reliably used in a home brew short period vertical spring >>> seismometer? I note no reference to such a trial; but that doesn't exclude >>> that someones hasn't already experimented with such? >>> This excludes known boom mounted balls on a mast flat. The size/weight >>> of the seismometer mass in mind is similar to that of the AS1. >>> >> This was effectively done with cylinders rolling on a plane with the > EAI vertical seismometer, now discontinued. I still have a copy of the > manual. > *It doesn't "sound" like they were too confident about that model; or, it required perhaps too many adjustments by the buyer. > You need to space the two balls fairly well apart on the upright to > prevent them from slipping due to horizontal seismic motions. It is also > desirable to design the arm so that there is no vertical force on the > rolling contacts. You attach the spring just behind the centre of mass and > the weight of the arm is balanced by the weight of the mass about this > attachment point. > Alternatively, you can fit an I bar across the vertical and make a C > fitting to go around it, attached to the end of the arm. You can then use > two piano wires under tension from the ends of the C to the enclosed I. > > > I would also assume that it is likely necessary to have any such balls > mounted on the side of a mechanical support/s to fix the spring opposition. > > It would necessitate two such pivots for maintaining vertical positional > reliability...i.e.; the "boom" would need to be "T" shaped to constrain its > otherwise undesirable lateral movement with only one pivot. > > > Regards, > > Chris Chapman > Take care, Meredith Lamb Hi Chris and all,

On Mon, Jul 13, 2009 at 8:51 PM, <ChrisAtUpw@.......> wrote:

In a message dated 13/07/2009, paleoartifact@......... writes:

=A0

Hi All,

=A0

=A0=A0=A0=A0Both http://www.myeclectic.info/SeismoPivots/seism= opivots.htm =A0 and http://myeclectic.info/SeismoPivots/seismopivots.htm=A0both seem to work on my Internet Explorer

BACKGROUND PIVOT:=A0 Chris Chapman's newer horizontal designs with= his lower pivot being a boom end flat that is=A0pivoting on a mast mounted= ball bearing seems to be a very ideal, reliable and much more stable "= ;standard pivot" for those of us endeavoring=A0=A0to make a commonly u= sed=A0home brew horizontal seismometer.=A0 It was studied in 2008 by him, C= harles Patton and Brett Nordgren and=A0briefly described by the web paper:= =A0

=A0=A0=A0=A0See Lehman photo=A0 http://jcla= hr.com/science/psn/chapman/2008%20lehman/lehman_prototype.jpg=A0
<= /blockquote>
=A0

*Chris, beautiful work on the seismo!=A0 =A0I=A0agree it apparently ha= s several significant improvements over that of the SEP seismometer sold th= ere in=A0the United Kingdom and elsewhere.=A0 I wanted to try the pivot las= t year but didn't get around

to a trial.=A0 Perhaps (?), this year I might be able to do so...with = a "test=A0setup" assembly I'am planning and constructing.
=A0

*For those readers interested in the SEP seismometer, and, if you have= a broadband connection; Youtube has a good

recent video of the "UK School Seismology: seismometer assembly&q= uot;=A0film produced by the British Geological Survey.=A0 Go to

Youtube and in the search box, enter in the title above.=A0 The BGS ha= s a Youtube "channel" (index) with other interesting videos also.= =A0=A0The SEP uses upper suspension and lower boom, crossed rods pivots.
=A0

=A0

=A0=A0=A0=A0This uses a 16 thou thick SS strip cut from a scalpel blad= e glued to the end of the arm, rolling on=A0a 1/2" SS ball on the upri= ght.=A0This has a MUCH better stability than a ball rolling on a plane.
=A0=A0=A0=A0Also note the 30 lb 7 core V SS fishing trace suspension, = which prevents the arm from rotating about it's long axis. I tested thi= s suspension OK for stable periods of up to 60 seconds. Note also that the = frame level screws use a wavy washer and=A0a locknut to prevent rotation as= the frame expands or contracts when the temperature changes. This seemed t= o improve the long term drift stability quite a bit. SS dome nuts make a ve= ry good rolling contact on the lower ends of levelling screws.

=A0=A0=A0=A0I find that 1/16" copper is preferable to Aluminum fo= r the damping plate. Aluminum is slightly paramagnetic and the edges of an = Al plate need to overlap the damping magnets at all times. If you don't= do this, the arm will skate sideways to the stop if the edge of the Al pla= te comes close to the edges of the magnets.

=A0

=A0=A0=A0=A0A square section coil is attached to the underside of the = Al mounting block. This photo was taken before the sensor cable was install= ed along the arm.

The question that comes up from all this is whether such a lower pivot= /s could be=A0~ reliably used=A0in a home brew short period vertical spring= seismometer?=A0 I note no reference to such a trial; but that doesn't = exclude that someones hasn't already experimented=A0with=A0such?

This excludes known boom mounted balls on a mast flat.=A0 The size/wei= ght of the seismometer mass in mind is similar to that of the AS1.

=A0=A0=A0=A0This was effectively done with cylinders rolling on a plan= e with the EAI vertical seismometer, now discontinued. I still have a copy = of the manual.

=A0

*It doesn't "sound" like they were too=A0confident about= that model; or, it required perhaps too many adjustments by

the buyer.

=A0

=A0

=A0=A0=A0=A0You need to space the two balls fairly well apart on the u= pright=A0to prevent them from slipping due to horizontal seismic motions. I= t is also desirable to design the arm so that there is no vertical force on= the=A0 rolling contacts. You attach the spring just behind the centre of m= ass and the weight of the arm is balanced by the weight of the mass about t= his attachment point.

=A0=A0=A0=A0Alternatively, you can fit an I bar across the vertical an= d make a C fitting to go around it, attached to the end of the arm. You can= then use two piano wires under tension from the ends of the C to the enclo= sed I.

=A0

I would also=A0assume that it=A0is likely=A0necessary to have any such= balls mounted on the side of a mechanical support/s to=A0fix the spring op= position.

=A0

It would necessitate two such pivots for=A0maintaining vertical positi= onal reliability...i.e.; the "boom"=A0would need to be "T&qu= ot; shaped to constrain its otherwise undesirable lateral movement with onl= y one pivot.=A0

=A0

=A0=A0=A0=A0Regards,

=A0

=A0=A0=A0=A0Chris Chapman

=A0

Take care, Meredith Lamb

Subject: MAJ quake report From: Dave Nelson dave.nelson@............... Date: Wed, 15 Jul 2009 20:37:51 +1000 hi all major earthquake in the SW of the South Island of New Zealand my ol' homeland. my parents phoned me within minutes of the event and said the shaking lasted for upwards of 1min 30sec and they are ~ 300km NE of the epicentre They described is as quite strong shaking rather than the usual low freq rolling motion of large distant quakes Region: OFF W. COAST OF S. ISLAND, N.Z. (Actually with in the fiords of that region,technically onshore...just) Geographic coordinates: 45.721S, 166.643E Magnitude: 7.8 Mw Depth: 35 km (locally listed at ~ 5km, very shallow) Universal Time (UTC): 15 Jul 2009 09:22:32 Time near the Epicenter: 15 Jul 2009 20:22:32 Local standard time in your area: 15 Jul 2009 19:22:32 cheers Dave N Sydney Australia __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: MAJ quake report From: Steinar Midtskogen steinar@............. Date: Wed, 15 Jul 2009 12:55:15 +0200 > Region: OFF W. COAST OF S. ISLAND, N.Z. (Actually with in the fiords > of that region,technically onshore...just) > Geographic coordinates: 45.721S, 166.643E > Magnitude: 7.8 Mw According to nzherald.co.nz estimates vary from 6.6 to 8.2 - that's a huge span. http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10584718 My seismometer is nearly 18.000 km away and the P wave was huge, so it looks closer to 8 than 7 to me. -- Steinar __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Any other USGS ftp Sites From: Larry Cochrane lcochrane@.............. Date: Wed, 15 Jul 2009 10:25:54 -0700 Hi Everyone, Gary Lindgren found this USGS event report http://neic.usgs.gov/neis/finger/cnss_14.fing that will work within WinQuake. To use this report you will need to update your report.dat and network.dat files, located in the WinQuake root directory, with the files contained in this zip file http://www.seismicnet.com/software/EventReportFiles.zip. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Short period spring vertical lower pivot question From: ChrisAtUpw@....... Date: Wed, 15 Jul 2009 18:58:05 EDT In a message dated 15/07/2009, paleoartifact@......... writes: Outside of buying anything.... versus home building, the old Georgia Tech vertical (Classroom Demonstration model) still remains as a quite interesting experimental setup; especially because they claim it is capable of much longer periods. It is rather strange that after some 11 years of its existence on the web that there is still no known private individual that has garnered up a web site on such with their opinion of merit. Of course the original design was of wood and some metal, and lacked a basic viable sensor and dampening; but the spring and pivot arrangement was the main very interesting approach idea for a long period seismometer. For readers it is at: _http://quake.eas.gatech.edu/Instruments/LPVERT0.htm_ (http://quake.eas.gatech.edu/Instruments/LPVERT0.htm) Hi Meredith, I agree that this is a good design. The problem with all amateur vertical sensors is the spring. Steel coil springs have quite a high temperature coefficient of the modulus, so you are limited to periods of less than about 6 seconds for simple systems, unless you add a full force feedback loop. If you try to make a longer natural period, the system will simply collapse as the room temperature increases. The second limitation is in the extension springs that you can buy. They all have a relatively low initial tension, whereas seismometer springs require quite a high initial tension. You can wind springs with a much higher initial tensions by either twisting the wire as it is wound onto a mandrel, or by pre-bending the wire in the direction of the spring axis, as LaCoste did. This design can also be compensated for atmospheric pressure noise - the principle source of noise by a large factor in uncompensated vertical systems. Regards, Chris Chapman

In a message dated 15/07/2009, paleoartifact@......... writes:

Outside of buying anything.... versus home building, the old= Georgia Tech vertical (Classroom

Demonstration model) still remains as a quite interesting experimen= tal setup; especially because they claim it is capable of much longer periods. It is rather strange that after some 11 years of its= existence on the web that there is still no known private individual tha= t has garnered up a web site on such with their opinion of merit.

Of course the original design was of wood and some metal, and lacke= d a basic viable sensor and dampening; but the spring and pivot arrangement= was the main very interesting approach idea for a long period seismometer.

For readers it is at: http://quake.eas.gatech.edu/Instruments/LPVERT0.htm<= /DIV>

Hi Meredith,

    I agree that this is a good design. The probl= em with all amateur vertical sensors is the spring. Steel coil springs have= quite a high temperature coefficient of the modulus, so you are limited to periods= of less than about 6 seconds for simple systems, unless you add a full force= feedback loop. If you try to make a longer natural period, the system will= simply collapse as the room temperature increases.

    The second limitation is in the extension spr= ings that you can buy. They all have a relatively low initial tension, whereas= seismometer springs require quite a high initial tension. You can wind spr= ings with a much higher initial tensions by either twisting the wire as it is= wound onto a mandrel, or by pre-bending the wire in the direction of the spring= axis, as LaCoste did.

    This design can also be compensated for atmos= pheric pressure noise - the principle source of noise by a large factor in= uncompensated vertical systems.

    Regards,

    Chris Chapman
Subject: Re: Short period spring vertical lower pivot question From: meredith lamb paleoartifact@......... Date: Fri, 17 Jul 2009 09:14:51 -0600 Hi Chris, Yes; the commercial available springs are a problem (unless one is satisfied with a 1 to ~ 6 sec period vertical); and/or use a form of feedback. Even with a zero length spring (such as in my old Sprengnether), temperature changes made it tough to keep roughly centered within a series of 3 ~ enclosures with a set period of 15 seconds. Just noted a interesting web article this morning on the Physics Forums web site about "Designing and making springs with music wire" (Circa May-June 2009). Its at: http://www.physicsforums.com/showthread.php?t=315723 Although the wire was twisted prior to spring forming; it doesn't really sound like a "real" zero length spring too me....but....such might be ~ better ~ than a common hardware spring. I don't have the expertise to evaluate the spring discussion technical implications to be frank. Take care, Meredith Lamb On Wed, Jul 15, 2009 at 4:58 PM, wrote: > In a message dated 15/07/2009, paleoartifact@......... writes: > > Outside of buying anything.... versus home building, the old Georgia Tech > vertical (Classroom > Demonstration model) still remains as a quite interesting experimental > setup; especially because they claim it is capable of much longer > periods. It is rather strange that after some 11 years of its existence on > the web that there is still no known private individual that has garnered up > a web site on such with their opinion of merit. > Of course the original design was of wood and some metal, and lacked a > basic viable sensor and dampening; but the spring and pivot arrangement was > the main very interesting approach idea for a long period seismometer. > For readers it is at: http://quake.eas.gatech.edu/Instruments/LPVERT0.htm > > Hi Meredith, > > I agree that this is a good design. The problem with all amateur > vertical sensors is the spring. Steel coil springs have quite a high > temperature coefficient of the modulus, so you are limited to periods of > less than about 6 seconds for simple systems, unless you add a full force > feedback loop. If you try to make a longer natural period, the system will > simply collapse as the room temperature increases. > > The second limitation is in the extension springs that you can buy. > They all have a relatively low initial tension, whereas seismometer springs > require quite a high initial tension. You can wind springs with a much > higher initial tensions by either twisting the wire as it is wound onto a > mandrel, or by pre-bending the wire in the direction of the spring axis, as > LaCoste did. > > This design can also be compensated for atmospheric pressure noise - > the principle source of noise by a large factor in uncompensated vertical > systems. > > Regards, > > Chris Chapman >
Hi Chris,

=A0

Yes; the commercial available springs are a problem (unless one is sat= isfied with a 1 to ~ 6=A0sec period vertical); and/or

use a form of feedback.=A0 Even with a zero length spring (such as in = my old Sprengnether), temperature changes made

it tough to keep roughly centered within a series of=A03 ~ enclosures = with a set period of 15 seconds.

=A0

Just noted a interesting web article this morning on the Physics Forum= s web site about "Designing and making springs

with music wire" (Circa May-June 2009).=A0 Its at:

=A0

http://www.physicsforums.com/showthread.php?t=3D315723
=A0

Although the wire was twisted prior to spring forming; it doesn't= =A0really sound like a "real" zero length spring too

me....but....such might be ~ better ~ than a=A0common hardware spring.= =A0 I don't have the expertise to=A0evaluate the=A0spring discussion te= chnical implications to be frank.=A0

=A0

Take care, Meredith Lamb

=A0

=A0

On Wed, Jul 15, 2009 at 4:58 PM, <ChrisAtUpw@a= ol.com> wrote:

In a message dated 15/07/2009, paleoartifact@......... writes:

Outside of buying anything.... versus home building,=A0 the old Georgi= a Tech vertical (Classroom

Demonstration model) still remains as a quite interesting experimental= setup; especially because they claim it is capable of much longer periods.= =A0It is rather=A0strange that after some 11 years of its existence on the = web that there is still no known private individual that has garnered up a = web site on such with their opinion of merit.

Of course the original design was of wood and some metal, and lacked a= basic viable sensor and dampening; but the spring and pivot arrangement wa= s the main=A0very interesting approach idea for a long period seismometer.<= /div>
For readers it is at: http://quake.eas.gatech.edu/Instruments/LPVERT0.htm

Hi Meredith,

=A0

=A0=A0=A0=A0I agree that this is a good design. The problem with all a= mateur vertical sensors is the spring. Steel coil springs have quite a high= temperature coefficient of the modulus, so you are limited to periods of l= ess than about 6 seconds for simple systems, unless you add a full force fe= edback loop. If you try to make a longer natural period, the system will si= mply collapse as the room temperature increases.

=A0

=A0=A0=A0=A0The second limitation is in the extension springs that you= can buy. They all have a relatively low initial tension, whereas seismomet= er springs require quite a high initial tension. You can wind springs with = a much higher initial tensions by either twisting the wire as it is wound o= nto a mandrel, or by pre-bending the wire in the direction of the spring ax= is, as LaCoste=A0did.

=A0

=A0=A0=A0=A0This design can also be compensated for atmospheric pressu= re noise - the principle source of noise by a large factor=A0in uncompensat= ed vertical systems.

=A0

=A0=A0=A0=A0Regards,

=A0

=A0=A0=A0=A0Chris Chapman

Subject: Re: Short period spring vertical lower pivot question From: ChrisAtUpw@....... Date: Fri, 17 Jul 2009 14:17:08 EDT In a message dated 17/07/2009, paleoartifact@......... writes: Yes; the commercial available springs are a problem (unless one is satisfied with a 1 to ~ 6 sec period vertical); and/or use a form of feedback. Even with a zero length spring (such as in my old Sprengnether), temperature changes made it tough to keep roughly centered within a series of 3 ~ enclosures with a set period of 15 seconds. Hi Meredith, That is why Sprengnethers were often fitted with a U made from a bimetal sandwich and a mass. You could trim out the drift error. They were designed for periods of 30 seconds, but were commonly used at 15 seconds. Just noted a interesting web article this morning on the Physics Forums web site about "Designing and making springs with music wire" (Circa May-June 2009). Its at: _http://www.physicsforums.com/showthread.php?t=315723_ (http://www.physicsforums.com/showthread.php?t=315723) Although the wire was twisted prior to spring forming; it doesn't really sound like a "real" zero length spring too me....but....such might be ~ better ~ than a common hardware spring. I don't have the expertise to evaluate the spring discussion technical implications to be frank. Thanks. You can get a true zero length spring this way. The problem with winding them, is that this is quite a high initial tension. If you put on too much tension, the spring ties itself in knots as you take it off the mandrel ! Common hardware springs have a low initial tension, but I don't know about the long springs that are used for sliding doors. Regards, Chris
In a message dated 17/07/2009, paleoartifact@......... writes:

Yes; the commercial available springs are a problem (unless one is= satisfied with a 1 to ~ 6 sec period vertical); and/or use a form= of feedback. Even with a zero length spring (such as in my old Sprengnether), temperature changes made it tough to keep roughly centere= d within a series of 3 ~ enclosures with a set period of 15 seconds.

Hi Meredith,

    That is why Sprengnethers were often fitted= with a U made from a bimetal sandwich and a mass. You could trim out the drift er= ror. They were designed for periods of 30 seconds, but were commonly used at 15= seconds.

Just noted a interesting web article this morning on the Physics Fo= rums web site about "Designing and making springs with music wire" (Circa May= -June 2009). Its at:

http://www.physicsforums.com/showthread.php?t=3D315723

Although the wire was twisted prior to spring forming; it doesn't really sound like a "real" zero length spring too me....but....such might be ~ better ~ than a common hardware spring. I don't have the expertise to evaluate the sprin= g discussion technical implications to be frank.

    Thanks.

    You can get a true zero length spring this wa= y. The problem with winding them, is that this is quite a high initial tension.= If you put on too much tension, the spring ties itself in knots as you take it of= f the mandrel ! Common hardware springs have a low initial tension, but I don't= know about the long springs that are used for sliding doors.

    Regards,

    Chris
Subject: Re: Short period spring vertical lower pivot question From: "Geoffrey" gmvoeth@........... Date: Fri, 17 Jul 2009 11:20:59 -0700 Hello PSN; I have found by surrounding my electronics with a series of small jars filled with salt water I am able to eliminate some low frequency undulations in the output. I think surrounding anything with a quantity of such water will moderate thermal changes by adding thermal inertia to the system. Sort of like a thermal capacitor. Has anyone ever tried such a thing before with one of your Very Low Frequency geophones? Here it is like 115F outside anf 85F inside the air conditioner will cycle with variations up to 20F. I believe the water is greatly moderating those thermal undulations and their effects on the electronics. If only I could surround the entire house with such a water jacket maybe 3 ft thick. :-) Regards geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Friday, July 17, 2009 8:14 AM Subject: Re: Short period spring vertical lower pivot question > Hi Chris, > > Yes; the commercial available springs are a problem (unless one is satisfied > with a 1 to ~ 6 sec period vertical); and/or > use a form of feedback. Even with a zero length spring (such as in my old > Sprengnether), temperature changes made > it tough to keep roughly centered within a series of 3 ~ enclosures with a > set period of 15 seconds. > > Just noted a interesting web article this morning on the Physics Forums web > site about "Designing and making springs > with music wire" (Circa May-June 2009). Its at: > > http://www.physicsforums.com/showthread.php?t=315723 > > Although the wire was twisted prior to spring forming; it doesn't really > sound like a "real" zero length spring too > me....but....such might be ~ better ~ than a common hardware spring. I > don't have the expertise to evaluate the spring discussion technical > implications to be frank. > > Take care, Meredith Lamb > > > On Wed, Jul 15, 2009 at 4:58 PM, wrote: > >> In a message dated 15/07/2009, paleoartifact@......... writes: >> >> Outside of buying anything.... versus home building, the old Georgia Tech >> vertical (Classroom >> Demonstration model) still remains as a quite interesting experimental >> setup; especially because they claim it is capable of much longer >> periods. It is rather strange that after some 11 years of its existence on >> the web that there is still no known private individual that has garnered up >> a web site on such with their opinion of merit. >> Of course the original design was of wood and some metal, and lacked a >> basic viable sensor and dampening; but the spring and pivot arrangement was >> the main very interesting approach idea for a long period seismometer. >> For readers it is at: http://quake.eas.gatech.edu/Instruments/LPVERT0.htm >> >> Hi Meredith, >> >> I agree that this is a good design. The problem with all amateur >> vertical sensors is the spring. Steel coil springs have quite a high >> temperature coefficient of the modulus, so you are limited to periods of >> less than about 6 seconds for simple systems, unless you add a full force >> feedback loop. If you try to make a longer natural period, the system will >> simply collapse as the room temperature increases. >> >> The second limitation is in the extension springs that you can buy. >> They all have a relatively low initial tension, whereas seismometer springs >> require quite a high initial tension. You can wind springs with a much >> higher initial tensions by either twisting the wire as it is wound onto a >> mandrel, or by pre-bending the wire in the direction of the spring axis, as >> LaCoste did. >> >> This design can also be compensated for atmospheric pressure noise - >> the principle source of noise by a large factor in uncompensated vertical >> systems. >> >> Regards, >> >> Chris Chapman >> > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Running multiple versions of Amaseis? From: "Edward Ianni" edwianni1@........... Date: Sun, 19 Jul 2009 09:13:10 -0400 Is it there any way to run multiple versions of Amaseis (with 3 = sensor inputs) on one computer simultaneously (using Windows XP, DI194-4 = input, ADC ). I have looked thru the archives but I was unable to find = anything specific pertaining to it or how to go about it, if it's = possible. Thank you very much. Sincerely Ed.

Is it there any way to run = multiple versions=20 of Amaseis (with 3 sensor inputs) on one computer = simultaneously=20 (using Windows XP, DI194-4 input, ADC ). I have looked thru the = archives=20 but I was unable to find anything specific pertaining to it or how to = go about=20 it, if it's possible. Thank you very much.  Sincerely=20 Ed.
Subject: Two Articles On Earthquakes From: Bob Hancock icarus@......... Date: Sun, 19 Jul 2009 13:25:23 -0700 > > http://www.sciencedaily.com/videos/2008/1210-big_quakes_trigger_small_quakes.htm > > http://www.sciencedaily.com/videos/2007/1007- > underwater_earthquakes.htm >

=

The recent M7.8 New Zealand EQ produced " T " waves which = showed=20 up very strongly on my geophone.

"T" phase & is seen for big events - it is transmitted through = the=20 ocean water, rather than through the rock below - hence it is = slower =20 - only seen for events under oceans ( & probably have to be shallow = as=20 well)

http://www.d= aleh.id.au/New_Zealand_M_7.8_T_wave.gif

regards

Dale
Subject: Re: Running multiple versions of Amaseis? From: Robert McClure bobmcclure90@......... Date: Sun, 19 Jul 2009 23:46:30 -0400 Hi Ed, The short answer to your question is no. You cannot use Amaseis to record more than one channel unless you use separate ADC's on separate ports, one for each channel. I have written a program for Dataq DI-xxx devices which records each channel's output in Amaseis format to separate folders labeled AmaseisA, AmaseisB, AmaseisC, etc. Copies of Amaseis can be placed in these folders and used to display the data in drum plot format. However, the current hour's data cannot be displayed, nor can any real-time filtering be used. In light of the above difficulties, I have not chosen to make this program available to others. If you are using the Dataq DI-194, I recommend using the recording and display programs available at http://bobmcclure90.googlepages.com Also, I urge you to replace your DI-194 with the DI-158U. Ten-bit resolution is inadequate for any useful dynamic range. I find twelve bits to be adequate, barely. ---Bob PSN Station REM, Locust Valley, NY > > Is it there any way to run multiple versions of Amaseis (with 3 > sensor inputs) on one computer simultaneously (using Windows XP, > DI194-4 input, ADC ). I have looked thru the archives but I was unable > to find anything specific pertaining to it or how to go about it, if > it's possible. Thank you very much. Sincerely Ed. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: T wave From: "Geoffrey" gmvoeth@........... Date: Mon, 20 Jul 2009 09:37:53 -0700 I believe this is what I saw too. ----- Original Message ----- From: "Dale Hardy" To: "PSN" Sent: Sunday, July 19, 2009 4:43 PM Subject: T wave The recent M7.8 New Zealand EQ produced " T " waves which showed up very strongly on my geophone. "T" phase & is seen for big events - it is transmitted through the ocean water, rather than through the rock below - hence it is slower - only seen for events under oceans ( & probably have to be shallow as well) http://www.daleh.id.au/New_Zealand_M_7.8_T_wave.gif regards Dale __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: T wave From: "Gary Lindgren" gel@................. Date: Mon, 20 Jul 2009 10:58:23 -0700 Dale, How do you differentiate the "T" and the Love and Raleigh waves. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Dale Hardy Sent: Sunday, July 19, 2009 4:43 PM To: PSN Subject: T wave The recent M7.8 New Zealand EQ produced " T " waves which showed up very strongly on my geophone. "T" phase & is seen for big events - it is transmitted through the ocean water, rather than through the rock below - hence it is slower - only seen for events under oceans ( & probably have to be shallow as well) http://www.daleh.id.au/New_Zealand_M_7.8_T_wave.gif regards Dale

Dale,

How do you differentiate the “T” and the Love = and Raleigh waves.

Gary

From:= = psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Dale Hardy
Sent: Sunday, July 19, 2009 4:43 PM
To: PSN
Subject: T wave

The recent M7.8 New Zealand EQ produced " T " waves which showed up very strongly on my = geophone.

"T" phase & is seen for big events - = it is transmitted through the ocean water, rather than through the rock = below - hence it is slower - only seen for events under oceans ( & = probably have to be shallow as well)

http://www.d= aleh.id.au/New_Zealand_M_7.8_T_wave.gif

regards

Dale

Subject: Re: T wave From: "Dale Hardy" photon1@........... Date: Tue, 21 Jul 2009 19:32:38 +1000 Hi Gary, from what I have read, the T waves travel at approximately 1500m/s. I = live about 2km from the ocean and measured the velocity at 1550m/s. I = suppose the conversion from a 'water' wave back to a seismic wave must = consume enormous energy generating a shock wave. I have seen these = before with events from Fiji and Vanuatu region but never realised what = they were, assumed them to be bug quakes etc. On a local TV news report = a trawler fisherman recounted how the fish suddenly vanished during his = night of fishing, he was unaware of the event but the fish were probably = shocked out of their scales :). I found a good article on T waves at = http://www.earth.northwestern.edu/people/emile/PDF/EAO050.pdf regards Dale ----- Original Message -----=20 From: Gary Lindgren=20 To: psn-l@................. Sent: Tuesday, July 21, 2009 3:58 AM Subject: RE: T wave Dale, How do you differentiate the "T" and the Love and Raleigh waves. Gary =20 =20 =20 =20 =20 From: psn-l-request@.............. = [mailto:psn-l-request@............... On Behalf Of Dale Hardy Sent: Sunday, July 19, 2009 4:43 PM To: PSN Subject: T wave =20 The recent M7.8 New Zealand EQ produced " T " waves which showed up = very strongly on my geophone. "T" phase & is seen for big events - it is transmitted through the = ocean water, rather than through the rock below - hence it is slower - = only seen for events under oceans ( & probably have to be shallow as = well) =20 http://www.daleh.id.au/New_Zealand_M_7.8_T_wave.gif =20 regards =20 Dale -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.392 / Virus Database: 270.13.20/2249 - Release Date: = 07/19/09 17:59:00
Hi Gary,

from what I have read, the T waves travel at = approximately=20 1500m/s. I live about 2km from the ocean and measured the velocity = at=20 1550m/s. I suppose the conversion from a 'water' wave back to a seismic = wave=20 must consume enormous energy generating a shock wave. I have seen = these=20 before with events from Fiji and Vanuatu region but never realised what = they=20 were, assumed them to be bug quakes etc. On a local TV news = report a=20 trawler fisherman recounted how the fish suddenly vanished during his = night of=20 fishing, he was unaware of the event but the fish were probably shocked = out of=20 their scales :).

I found a good article on T waves at = ht= tp://www.earth.northwestern.edu/people/emile/PDF/EAO050.pdf

regards

Dale

----- Original Message -----
From:=20 Gary=20 Lindgren

To: psn-l@..............

Sent: Tuesday, July 21, 2009 = 3:58=20 AM

Subject: RE: T wave

Dale,

How=20 do you differentiate the =93T=94 and the Love and Raleigh=20 waves.

Gary

From: psn-l-request@............... =20 [mailto:psn-l-request@............... On Behalf Of Dale=20 Hardy
Sent: Sunday, July 19, 2009 4:43 PM
To:=20 PSN
Subject: T wave

The recent M7.8 New Zealand EQ produced " = T "=20 waves which showed up very strongly on my = geophone.

"T" phase & is seen for big events - it is = transmitted=20 through the ocean water, rather than through the rock below - = hence it=20 is slower - only seen for events under oceans ( & probably = have to=20 be shallow as well)

http://www.d= aleh.id.au/New_Zealand_M_7.8_T_wave.gif

regards

Dale

No virus found in this incoming message.
Checked by AVG = -=20 www.avg.com
Version: 8.5.392 / Virus Database: 270.13.20/2249 - = Release=20 Date: 07/19/09 17:59:00
Subject: Re: T wave From: "David Saum" DSaum@............ Date: Tue, 21 Jul 2009 08:40:46 -0400 (EDT) I also noticed that the M7.8 NZ quake showed up strongly on my 4.5 Hz geophone, and when I looked at the power spectra most of the energy appeared to be above 1 Hz. In my previous large teleseismic geophone detections my power spectra have shown peaks around 0.02-0.04 Hz. Are T waves typically at higher frequencies? Dave > ----- Original Message ----- > From: "Dale Hardy" > To: "PSN" > Sent: Sunday, July 19, 2009 4:43 PM > Subject: T wave > > > The recent M7.8 New Zealand EQ produced " T " waves which showed up very > strongly on my geophone. > "T" phase & is seen for big events - it is transmitted through the ocean > water, rather than through the rock below - hence it is > slower - only seen for events under oceans ( & probably have to be > shallow as well) > > http://www.daleh.id.au/New_Zealand_M_7.8_T_wave.gif > > regards > > Dale __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Video of a experimental pivot From: meredith lamb paleoartifact@......... Date: Thu, 23 Jul 2009 12:35:13 -0600 Hi all, I put up on the web a video of a "old" experimental vertical pivot based on the Georgia Tech classroom demonstrator of a vertical seismometer. My index "channel" on youtube is at: http://www.youtube.com/pyrolytic The title of the video is: "Vertical seismometer experimental pivot". Perhaps the video can add a certain amount of "spice" and/or knowledge insight into the normally "dry" subject of seismometers and/or design, operation etc. The video is kind of a "ad-hoc" experiment in movie making on my part...it was not previously planned out. There is other different subjects of short clips therein also. One will need a broadband internet connection to view such as it is some 38 megabytes and almost 9 minutes long. Take care, Meredith Lamb
Hi all,

=A0

I put up on the web a video of a "old" experimental vertical= pivot based on the Georgia Tech classroom

demonstrator of a vertical seismometer.=A0 My index "channel"= ; on youtube is at:

=A0

http://www.youtube.com/py= rolytic

=A0

The title of the video is:=A0 "Vertical seismometer experimental = pivot".

=A0

Perhaps the video=A0can add a certain amount of "spice" and/= or knowledge=A0insight into the normally "dry"

subject of seismometers and/or design, operation etc.=A0 The video is = kind of a "ad-hoc" experiment in

movie making on my part...it was not=A0previously planned out.

=A0

There is other different subjects of short clips therein also.

=A0

One will need a broadband internet connection to view such as it is so= me 38 megabytes and almost

9 minutes long.

=A0

Take care, Meredith Lamb

=A0

=A0

=A0

=A0

=A0

=A0

=A0

=A0
Subject: Re: Video of a experimental pivot From: "Geoffrey" gmvoeth@........... Date: Thu, 23 Jul 2009 22:09:32 -0700 Howdy Meredith lamb, Neato, Would it be possible to change the ratio of the pivot point to 18 to 25 centimeters on the weight side and one centimeter on the spring side and greatly reducing the mass to get a longer period ? I guess you need to reduce the mass by the mechanical advantage of the ratio. What kind of washers are those so shiny you can see the JVC camera in it ?? Filing cabinets in the reflection. Range limits are necessary so the device can be carried/moved. Where would the damper go ? It would be nice to have two such devices in opposite directions to cancel out tilt in a diff amp. Two such matched devices are necessary for proper operation. Where would a magnetic damper go ? regards geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Thursday, July 23, 2009 11:35 AM Subject: Video of a experimental pivot Hi all, I put up on the web a video of a "old" experimental vertical pivot based on the Georgia Tech classroom demonstrator of a vertical seismometer. My index "channel" on youtube is at: http://www.youtube.com/pyrolytic The title of the video is: "Vertical seismometer experimental pivot". Perhaps the video can add a certain amount of "spice" and/or knowledge insight into the normally "dry" subject of seismometers and/or design, operation etc. The video is kind of a "ad-hoc" experiment in movie making on my part...it was not previously planned out. There is other different subjects of short clips therein also. One will need a broadband internet connection to view such as it is some 38 megabytes and almost 9 minutes long. Take care, Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Video of a experimental pivot From: meredith lamb paleoartifact@......... Date: Fri, 24 Jul 2009 12:23:01 -0600 On Thu, Jul 23, 2009 at 11:09 PM, Geoffrey wrote: > Howdy Meredith lamb, > > Neato, Would it be possible to change the ratio > of the pivot point to 18 to 25 centimeters on the weight side > and one centimeter on the spring side and greatly reducing > the mass to get a longer period ? > > I guess you need to reduce the mass by the > mechanical advantage of the ratio. > ***Geoffrey; a lot of the "trials" of this design literally depends on the specific spring itself and its placement both on the end of the boom and where it is connected....which "could be" both behind the pivot point or in front of the pivot near the mass. I first tried a Servalite # 59 (which has seen a few other mentions on PSN); but that didn't seem to work very well, on this setup....regardless of placement. > > What kind of washers are those so shiny > you can see the JVC camera in it ?? > Filing cabinets in the reflection. > ***Those are the two pivots, that the rolling rod rests on the inside hole edge. I think they are actually computer hard drive disks coated in nickel chrome...but which were rejected for some reason. I did make the mistake of assuming that people already know what they are. Yes; they do look like washers. > > Range limits are necessary so the device can be > carried/moved. > > Where would the damper go ? > ***Normally the dampening usually goes near the mass as with most seismometers. Their is no dampening or sensor pickup on the video for the pivot (and quite literally the spring also) test. I am definitely not technically oriented to be up front. Perhaps the best summation of the test is that pivot "could" work, and that perhaps also that the Servalite spring #200 could be of much more major amateur interest and use in such. ***A note on the spring. While Ace hardware is where I got the spring from; Truevalue hardware or other hardware stores "may" have such. One would literally have to call their hardware stores and ask if they have a Servalite spring assortment.....and....if they have that specific spring. I think it cost ~ about 3 dollars. Most hardware stores are small and they don't have such. However; they may be able to special order such, likely at a higher cost. It would be nice to have two such devices in opposite directions to cancel out tilt in a diff amp. Two such matched devices are necessary for proper operation. Where would a magnetic damper go ? regards geoff ***The steel test base I used would normally be "condemned" for the temperature expansion & contraction...but it was just a readily made test platform. Take care, Meredith Lamb >

On Thu, Jul 23, 2009 at 11:09 PM, Geoffrey <gmvoeth@............ > wrote:

Howdy Meredith lamb,

Neat= o, Would it be possible to change the ratio
of the pivot point to 18 to = 25 centimeters on the weight side
and one centimeter on the spring side and greatly reducing
the mass to g= et a longer period ?

I guess you need to reduce the mass by the
m= echanical advantage of the ratio.

=A0

***Geoffrey; a lot of the "trials" of this design literally = depends on the specific spring itself and its placement both

on the end of the boom and where it is connected....which "could = be" both behind the pivot point or in

front of the pivot near the mass.=A0 I first tried a Servalite # 59 (w= hich has seen a few other mentions on PSN);

but that didn't seem to work very well, on this setup....regardles= s of placement.=A0

What kind of wa= shers are those so shiny
you can see the JVC camera in it ??
Filing c= abinets in the reflection.

=A0

***Those=A0are the two pivots, that the rolling rod rests on the insid= e hole edge.=A0 I think they are actually computer

hard drive disks coated in nickel chrome...but which were rejected for= some reason.=A0 I did make the mistake

of assuming that people already know what they are.=A0 Yes; they do lo= ok like washers.

Range limits ar= e necessary so the device can be
carried/moved.

Where would the d= amper go ?

=A0

***Normally the dampening usually goes near the mass as with most seis= mometers.=A0 =A0=A0Their is no dampening

or sensor pickup on the video for the pivot (and quite literally the s= pring also) test.=A0 I am definitely not technically

oriented to be up front.=A0 Perhaps the best summation of the test is = that pivot "could" work, and that=A0perhaps also

that the Servalite spring #200 could be of much more major amateur int= erest and use in such.=A0

=A0

***A note on the spring.=A0 While Ace hardware is where I got the spri= ng from; Truevalue hardware or other

hardware stores "may" have such.=A0 One would literally have= to call their hardware stores and ask if they have

a Servalite spring assortment.....and....if they have that specific sp= ring.=A0 I think it cost ~ about 3 dollars.=A0 Most

hardware stores are small and they don't have such.=A0 However; th= ey may be able to special order such, likely

at a higher cost.

=A0

It would be nice to have two such devices
in opposite directions to= cancel out tilt
in a diff amp.
Two such matched devices are necessar= y
for proper operation.

Where would a magnetic damper go ?

regards
geoff

=A0

***The steel test base I used would normally be "condemned" = for the temperature expansion & contraction...but

it was just a readily made test platform.

=A0

Take care, Meredith Lamb

Subject: Questions of the Temperature stability of the rolling pivot vertical From: meredith lamb paleoartifact@......... Date: Fri, 24 Jul 2009 14:38:34 -0600 Hi all, In regard to that vertical seismometer Georgia Tech classroom demonstrator Youtube pivot video variation and the "strange" computer disks and crossed rod pivot; their could be something going on that I don't understand. Here you have a all steel base, steel spring and one would normally expect a wide temperature effect on the position of the mass that the unit is experiencing in the garage. The garage is detached. The garage can see wide temperature variations. It probably exceeds 100 degrees inside at the height of the daily summer temperature swings in the daytime, and swings + or - 50 or more degrees lower in the early morning hours. The main point I'm making here is that the horizontal position doesn't seem to show any significant gross horizontal deflections of the mass either up or down that I can remember. The Servalite #200 spring is not a zero length spring. It was not changed or shortened by myself from the manufacturer. I suspect that the rolling pivot itself is somehow partly countering the temperature variations changes. Being as the pivot can roll, and the only positional change would have to come from the spring and/or steel base; it could be doing mass positional and temperature "self adjusting" in a way I don't fully understand. If....it is significantly "self adjusting", it would then seem to be a approach that "could" somewhat eliminate that normal temperature problem and open up the use of such similar steel and simple construction continued test use. I will make a effort to check more often at various times of the day or night for awhile. I'm going to put up a fixed visual mass elevation reference today at the height of the temperature range. Whatever the extreme variation is and the present temperature will be noted and documented. Even if the mass position varies 1/2" or so...that would certainly seem to be good enough for at least a amateur wire coil pickup and the normal eddy current dampening of a more complete seismometer. The computer disk pivots are internally aluminum with a nickel chrome like plating; and the boom is aluminum. Perhaps....its more likely all the aluminum, steel, spring and the rolling pivots are all together doing the temperature equalizing of the mass position horizontal stability? On the other hand, it could be the consequence of everything being "just right" for such. Comments are welcome. There might of course be low or high technical insight I'm overlooking or unaware of. Take care, Meredith Lamb PS: The number of video views for one full day hit ~90 on Youtube; which is a lot more than anticipated. PSN people were assumable the main response. Any reader with a camcorder might entertain the same "publishing" approach for their specific instrument/s....it appears to be a highly successful media approach..."A picture is worth a thousand words".
Hi all,

=A0

In regard to that vertical seismometer Georgia Tech classroom demonstr= ator Youtube pivot video variation and the "strange" computer dis= ks and crossed rod pivot; their could be something going on that I don'= t understand.=A0 Here you

have a all steel base, steel spring and one would normally expect a wi= de temperature effect on the position of the mass

that the unit is experiencing in the garage.=A0 The garage is detached= ..

=A0

The garage can see wide temperature variations.=A0 It probably exceeds= 100 degrees inside at the height

of the daily summer temperature swings in the daytime, and swings + or= - 50 or more degrees lower in the early

morning hours.

=A0

The main point I'm making here is that the horizontal position doe= sn't seem to show any significant gross

horizontal deflections of the mass either up or down that I can rememb= er.

=A0

The Servalite #200 spring is not a=A0zero length spring.=A0 It was not= changed or shortened by myself from the

manufacturer.

=A0

I suspect that the rolling pivot itself is somehow partly countering t= he temperature variations changes.=A0=A0 Being as the

pivot can roll, and the only positional change would have to come from= the spring and/or steel base; it

could=A0be doing mass positional and temperature "self adjusting&= quot; in a way I don't fully understand.

=A0

If....it is significantly "self adjusting", it would then se= em to be a approach that "could"=A0somewhat eliminate

that normal temperature problem and open up the use of such=A0similar = steel and simple=A0construction=A0continued test use.=A0=A0

=A0

I will make a effort to check more often at various times=A0of the day= or night for awhile.=A0=A0I'm going to put up

a fixed visual mass elevation reference today at the height of the tem= perature range.=A0 Whatever the extreme

variation is and the present temperature will be noted and documented.= =A0 Even if=A0the mass position varies 1/2" or

so...that would certainly seem to be good enough for at least a amateu= r wire coil pickup and the normal eddy current

dampening of a more complete seismometer.=A0

=A0

The computer disk pivots are internally aluminum with a nickel chrome = like plating; and the boom is aluminum.

=A0

Perhaps....its more likely all the aluminum, steel, spring=A0and the r= olling pivots are all together=A0doing the=A0temperature

equalizing of the mass position=A0horizontal stability?

=A0

On the other hand, it could be the consequence of everything being &qu= ot;just right" for such.

=A0

Comments are welcome.=A0 There might of course be low or high technica= l insight I'm overlooking or unaware of.

=A0

Take care, Meredith Lamb

=A0

PS:=A0 The number of video views for one full day hit ~90 on Youtube; = which is a lot more than anticipated.=A0 PSN people

were=A0assumable=A0the main response.=A0 Any reader with a camcorder m= ight entertain the same "publishing" approach

for their specific instrument/s....it appears to be a highly successfu= l media approach..."A picture is worth a thousand

words".

=A0

=A0

=A0

=A0

=A0
Subject: which seismometer? From: Jay Muza jmuza@........... Date: Fri, 24 Jul 2009 17:23:15 -0400 Hi I would like to purchase one of the inexpensive Lehman type seismometers cu= rrently on the market. The three I am considering are the AS-1, the UK Sch= ool of Seismology SEP Seismometer System, and the Rockwave HS-3. Any guida= nce..any at all...would be greatly appreciated. Thank you. Dr. Jay Muza Department of Physical Sciences Broward College Davie, FL 33314 Office: 954.201.6771 Cell: 954.736.8231 jmuza@........... Please Note: Due to Florida's very broad public records law, most written c= ommunications to or from College employees regarding College business are p= ublic records, available to the public and media upon request. Therefore, t= his email communication may be subject to public disclosure. Please consider the environment before printing this email. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Video of a experimental pivot From: "Geoffrey" gmvoeth@........... Date: Fri, 24 Jul 2009 16:11:57 -0700 Hello Meredith lamb, There is one other question I may ask ; Have you ever tried a torsion spring with this design ? I have tried using an aluminum alloy antenna element that is a tube split down the middle with a slot its full length. It seems to act as a spring quite well but not sure if its actually suitable for the job. It would totally eliminate the bulky extension spring. If you wish to derive the spring constant you can hang a water bottle with a measured amount of water to get enough weight to extend the spring maybe 10 inches then use a bit of math. You may control the overall temp of a working device ( I think two devices are necessary to be proper ) by placing gallon jugs of salt water brine surrounding the devices to make a thermal inertia to average out temp changes or so I believe. I think any linear constant extension spring made out of steel can do the right job if you can get at least 11 or more inches of extension. You must allow for any pretensioning because that will have an effect on its overall extension. The pretensioning will work out to some added extension amount to the measured results. Sort of a second degree correction factor to think about. That is how much water weight before spring shows first signs of extension. No reason you can not easily work out the spring constant for amateur needs. I like your Georgia Design But would absolutely need two such sensors for a complete whole. Please use eye protection, I blinded myself in one eye accidentally with a wild spring once, thank goodness it lasted only a few seconds before returning to normal. Springs can be dangerous to anyone's quality of life. No one is mistake free. Also Century Spring Company, they will build custom springs but charge a terrible initial setup fee of a few hundred dollars I think. You want to have maybe a hundred springs made all at once. Regards; Geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Friday, July 24, 2009 11:23 AM Subject: Re: Video of a experimental pivot On Thu, Jul 23, 2009 at 11:09 PM, Geoffrey wrote: > Howdy Meredith lamb, > > Neato, Would it be possible to change the ratio > of the pivot point to 18 to 25 centimeters on the weight side > and one centimeter on the spring side and greatly reducing > the mass to get a longer period ? > > I guess you need to reduce the mass by the > mechanical advantage of the ratio. > ***Geoffrey; a lot of the "trials" of this design literally depends on the specific spring itself and its placement both on the end of the boom and where it is connected....which "could be" both behind the pivot point or in front of the pivot near the mass. I first tried a Servalite # 59 (which has seen a few other mentions on PSN); but that didn't seem to work very well, on this setup....regardless of placement. > > What kind of washers are those so shiny > you can see the JVC camera in it ?? > Filing cabinets in the reflection. > ***Those are the two pivots, that the rolling rod rests on the inside hole edge. I think they are actually computer hard drive disks coated in nickel chrome...but which were rejected for some reason. I did make the mistake of assuming that people already know what they are. Yes; they do look like washers. > > Range limits are necessary so the device can be > carried/moved. > > Where would the damper go ? > ***Normally the dampening usually goes near the mass as with most seismometers. Their is no dampening or sensor pickup on the video for the pivot (and quite literally the spring also) test. I am definitely not technically oriented to be up front. Perhaps the best summation of the test is that pivot "could" work, and that perhaps also that the Servalite spring #200 could be of much more major amateur interest and use in such. ***A note on the spring. While Ace hardware is where I got the spring from; Truevalue hardware or other hardware stores "may" have such. One would literally have to call their hardware stores and ask if they have a Servalite spring assortment.....and....if they have that specific spring. I think it cost ~ about 3 dollars. Most hardware stores are small and they don't have such. However; they may be able to special order such, likely at a higher cost. It would be nice to have two such devices in opposite directions to cancel out tilt in a diff amp. Two such matched devices are necessary for proper operation. Where would a magnetic damper go ? regards geoff ***The steel test base I used would normally be "condemned" for the temperature expansion & contraction...but it was just a readily made test platform. Take care, Meredith Lamb > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: which seismometer? From: "Les LaZar" llazar@.................. Date: Fri, 24 Jul 2009 16:36:01 -0700 Hi Jay, At the risk of tooting my own horn... If your budget is flexible, you don't specifically need a Lehman type design and your application would benefit from a research-quality instrument, you may wish to consider the RLL Instruments VolksMeter II ( http://www.rllinstruments.com ). Many of these are currently being used in educational and research applications. Some are in use by psn members. If you are interested, I would be happy to answer any questions you might have. Regards, Les LaZar RLL Instruments / a division of Zoltech Corporation 818-780-1800 ----- Original Message ----- From: "Jay Muza" To: Sent: Friday, July 24, 2009 2:23 PM Subject: which seismometer? Hi I would like to purchase one of the inexpensive Lehman type seismometers currently on the market. The three I am considering are the AS-1, the UK School of Seismology SEP Seismometer System, and the Rockwave HS-3. Any guidance..any at all...would be greatly appreciated. Thank you. Dr. Jay Muza Department of Physical Sciences Broward College Davie, FL 33314 Office: 954.201.6771 Cell: 954.736.8231 jmuza@........... Please Note: Due to Florida's very broad public records law, most written communications to or from College employees regarding College business are public records, available to the public and media upon request. Therefore, this email communication may be subject to public disclosure. Please consider the environment before printing this email. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: which seismometer? From: "Jim ODonnell" geophysics@.......... Date: Sat, 25 Jul 2009 01:53:35 GMT Hi All- Observations of the RLL: For the last year I have been comparing Larry=92s sensors to his RLL (Vo= lksmeter- .lctst & .lctst1) and the results are rather outstanding. I = live close to Las Vegas so record mostly local events with 1 Hz & 4.5 Hz= geophones. But I have been considering the RLL as it gets them all=85.= Local, Regional, & Teleseismic. It is a Horizontal & I like to look at Rayleigh waves which are predomin= ately Z. Any chance of a RLL in Z??? <<<< Jim Jim O'Donnell- Geophysical Consultant/Contractor Geotechnical/Geothermal/Oil & Gas/Mining Applications Seismic Surveys- Surface Waves, Refraction, & Reflection Ground Penetrating Radar, Resistivity, Magnetic, & VLF-EM Surveys Geophysics@.......... 702.293.5664 702.281.9081 cell = Boulder City, NV ---------- Original Message ---------- From: "Les LaZar" To: Subject: Re: which seismometer? Date: Fri, 24 Jul 2009 16:36:01 -0700 Hi Jay, At the risk of tooting my own horn... If your budget is flexible, you don't specifically need a Lehman type de= sign = and your application would benefit from a research-quality instrument, y= ou = may wish to consider the RLL Instruments VolksMeter II ( = http://www.rllinstruments.com ). Many of these are currently being used= in = educational and research applications. Some are in use by psn members. If you are interested, I would be happy to answer any questions you migh= t = have. Regards, Les LaZar RLL Instruments / a division of Zoltech Corporation 818-780-1800 ----- Original Message ----- = From: "Jay Muza" To: Sent: Friday, July 24, 2009 2:23 PM Subject: which seismometer? Hi I would like to purchase one of the inexpensive Lehman type seismometers= = currently on the market. The three I am considering are the AS-1, the U= K = School of Seismology SEP Seismometer System, and the Rockwave HS-3. Any= = guidance..any at all...would be greatly appreciated. Thank you. Dr. Jay Muza Department of Physical Sciences Broward College Davie, FL 33314 Office: 954.201.6771 Cell: 954.736.8231 jmuza@........... Please Note: Due to Florida's very broad public records law, most writte= n = communications to or from College employees regarding College business a= re = public records, available to the public and media upon request. Therefor= e, = this email communication may be subject to public disclosure. Please consider the environment before printing this email. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) See http://www.seismicnet.com/maillist.html for more information.
Hi All-
Observations of the RLL:
For the last year I have been comparing Larry=92s sensors to his&nb= sp;RLL (Volksmeter- .lctst & .lctst1) and the results are= rather outstanding. I live close to Las Vegas so record mostly local events with 1= Hz & 4.5 Hz geophones. But I have been considering the RLL as it gets them all=85.Local, Reg= ional, & Teleseismic.
It is a Horizontal & I like to look at = Rayleigh waves which are predominately Z.
Any chance of a RLL in Z???=
<<<<    Jim

Jim O'Donnell- = Geophysical Consultant/Contractor
Geotechnical/Geothermal/Oil & G= as/Mining Applications
Seismic Surveys- Surface Waves, Refraction, &a= mp; Reflection
Ground Penetrating Radar, Resistivity, Magnetic, &= VLF-EM Surveys
Geophysics@.......... 702.293.5664 702.28= 1.9081 cell
Boulder City, NV

---------- Origi= nal Message ----------
From: "Les LaZar" <llazar@.................. m>
To: <psn-l@..............>
Subject: Re: which seismome= ter?
Date: Fri, 24 Jul 2009 16:36:01 -0700

Hi Jay,

At t= he risk of tooting my own horn...

If your budget is flexible, you= don't specifically need a Lehman type design
and your application w= ould benefit from a research-quality instrument, you
may wish to con= sider the RLL Instruments VolksMeter II (
http://www.rllinstruments.= com ). Many of these are currently being used in
educational a= nd research applications. Some are in use by psn members.

I= f you are interested, I would be happy to answer any questions you might=
have.

Regards,

Les LaZar
RLL Instruments / a divis= ion of Zoltech Corporation
818-780-1800

----- Original Message= -----
From: "Jay Muza" <jmuza@...........>
To: <psn-l@w= ebtronics.com>
Sent: Friday, July 24, 2009 2:23 PM
Subject: whi= ch seismometer?

Hi
I would like to purchase one of the ine= xpensive Lehman type seismometers
currently on the market. The= three I am considering are the AS-1, the UK
School of Seismology SE= P Seismometer System, and the Rockwave HS-3. Any
guidance..any= at all...would be greatly appreciated. Thank you.

Dr. = Jay Muza
Department of Physical Sciences
Broward College
Davie,= FL 33314

Office: 954.201.6771
Cell:    9= 54.736.8231

jmuza@...........

Please Note: Due to Florida'= s very broad public records law, most written
communications to or f= rom College employees regarding College business are
public records,= available to the public and media upon request. Therefore,
this ema= il communication may be subject to public disclosure.

Please cons= ider the environment before printing this email.

________________= __________________________________________

Public Seismic Network= Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@SEIS= MICNET.COM with
the body of the message (first line only): unsubscrib= e
See http://www.seismicnet.com/maillist.html for more information.

__________________________________________________________=

Public Seismic Network Mailing List (PSN-L)

To leave this= list email PSN-L-REQUEST@.............. with
the body of the messag= e (first line only): unsubscribe
See http://www.seismicnet.com/mailli= st.html for more information.
Subject: Re: Questions of the Temperature stability of the rolling pivot vertical mas... From: ChrisAtUpw@....... Date: Fri, 24 Jul 2009 23:51:20 EDT In a message dated 24/07/2009, paleoartifact@......... writes: If....it is significantly "self adjusting", it would then seem to be a approach that "could" somewhat eliminate that normal temperature problem and open up the use of such similar steel and simple construction continued test use. Hi there, I suggest that you fit the end of the boom with a vertical position marker and a vertical ruler and also check the instrument temperature when checking the position. There is NO substitute for direct measurements! You don't see large position variations for periods under about 3 seconds. The temperature coefficient of Youngs modulus is 2.4 x 10^-4 / C Deg for steel. The expansion coeffieicnt is about 12 x 10^-6 / C Deg Regards, Chris Chapman
In a message dated 24/07/2009, paleoartifact@......... writes:

If....it is significantly "self adjusting", it would then seem to= be a approach that "could" somewhat eliminate that normal temperature pr= oblem and open up the use of such similar steel and simple construction continued test use.

Hi there,

    I suggest that you fit the end of the boom wi= th a vertical position marker and a vertical ruler and also check the instrumen= t temperature when checking the position. There is NO substitute for direct= measurements! You don't see large position variations for periods under ab= out 3 seconds.

    The temperature coefficient of Youngs modulus= is 2.4 x 10^-4 / C Deg for steel. The expansion coeffieicnt is about 12 x 10^= -6 / C Deg

    Regards,

    Chris Chapman
Subject: Re: Questions of the Temperature stability of the rolling pivot From: meredith lamb paleoartifact@......... Date: Fri, 24 Jul 2009 22:29:57 -0600 HI Chris, Will honor your recommendations; to see just how big a range of temperature versus positional drift it goes exhibit. Interesting on the short period v/s low drift sentence. It sounds like it would be a insignificant problem with a reasonable placement and cover to begin with....for this 3s unit. Thats good news. Take care, Meredith On Fri, Jul 24, 2009 at 9:51 PM, wrote: > In a message dated 24/07/2009, paleoartifact@......... writes: > > If....it is significantly "self adjusting", it would then seem to be a > approach that "could" somewhat eliminate that normal temperature problem and > open up the use of such similar steel and simple construction continued test > use. > > Hi there, > > I suggest that you fit the end of the boom with a vertical position > marker and a vertical ruler and also check the instrument temperature when > checking the position. There is NO substitute for direct measurements! You > don't see large position variations for periods under about 3 seconds. > > The temperature coefficient of Youngs modulus is 2.4 x 10^-4 / C Deg > for steel. The expansion coeffieicnt is about 12 x 10^-6 / C Deg > > Regards, > > Chris Chapman >
HI Chris,

=A0

Will honor your recommendations; to see just how big a range of temper= ature versus positional=A0drift it goes exhibit.

=A0

Interesting on the short period v/s low drift sentence.=A0 It sounds l= ike it would be a=A0insignificant problem with a reasonable

placement and cover to begin with....for this 3s unit.=A0 Thats good n= ews.

=A0

Take care, Meredith=A0=A0

On Fri, Jul 24, 2009 at 9:51 PM, <ChrisAtUpw@.......> wrote:

In a message dated 24/07/2009, paleoartifact@......... writes:

If....it is significantly "self adjusting", it would then se= em to be a approach that "could"=A0somewhat eliminate that normal= temperature problem and open up the use of such=A0similar steel and simple= =A0construction=A0continued test use.

Hi there,

=A0

=A0=A0=A0=A0I suggest that you fit the end of the boom with a vertical= position marker and a vertical ruler and also check the instrument tempera= ture when checking the position. There is NO substitute for direct measurem= ents! You don't see large position variations for periods under about 3= seconds.

=A0

=A0=A0=A0=A0The temperature coefficient of Youngs modulus is 2.4 x 10^= -4 / C Deg for steel. The expansion coeffieicnt is about 12 x 10^-6 / C Deg= =A0

=A0

=A0=A0=A0=A0Regards,

=A0

=A0=A0=A0=A0Chris Chapman

Subject: Re: Video of a experimental pivot From: meredith lamb paleoartifact@......... Date: Fri, 24 Jul 2009 22:34:19 -0600 Hi Geoffrey; On Fri, Jul 24, 2009 at 5:11 PM, Geoffrey wrote: > Hello Meredith lamb, > > There is one other question I may ask ; > > Have you ever tried a torsion spring > with this design ? > > I have tried using an aluminum alloy > antenna element that is a tube split down > the middle with a slot its full length. > It seems to act as a spring quite well > but not sure if its actually suitable for the job. > It would totally eliminate the bulky extension spring. > *** No I've not tried a torsion spring; but I get the idea. I think I'd rather stick with the traditional extension spring route for the time being. > > > If you wish to derive the spring constant > you can hang a water bottle with a measured > amount of water to get enough weight to > extend the spring maybe 10 inches then use > a bit of math. You may control the overall temp > of a working device ( I think two devices are necessary > to be proper ) by placing gallon jugs of salt > water brine surrounding the devices to make a thermal > inertia to average out temp changes or so > I believe. > > I think any linear constant extension spring made out of > steel can do the right job if you can get at least > 11 or more inches of extension. > *** It entirely depends on the spring used of course. The original cut Georgia tech spring (unloaded) was 4" length; and loaded it "looks" like ~ its perhaps 8". > > You must allow for any pretensioning because > that will have an effect on its overall extension. > The pretensioning will work out to some added > extension amount to the measured results. > Sort of a second degree correction factor > to think about. That is how much water weight before > spring shows first signs of extension. > *** I think a simple adequate weight scale would work to derive such and about any kind of add on weight. > > No reason you can not easily work out the spring constant > for amateur needs. > *** I'll give it a go. > > I like your Georgia Design But would absolutely need two > such sensors for a complete whole. > *** You mentioned measuring tilt that way earlier; but I don't think its that necessary. > > Please use eye protection, I blinded > myself in one eye accidentally > with a wild spring once, thank > goodness it lasted only a few seconds > before returning to normal. > Springs can be dangerous to anyone's > quality of life. No one is mistake free. > *** Yes, I've also been "bitten", whacked or cut a few times > > Also Century Spring Company, they will build custom > springs but charge a terrible initial setup fee of a > few hundred dollars I think. You want to have > maybe a hundred springs made all at once. > *** I won't be in production; I'd rather find/use something already on the common hardware market. Regards; > Geoff > > *** Take care, Meredith Lamb Hi Geoffrey;

On Fri, Jul 24, 2009 at 5:11 PM, Geoffrey <gm= voeth@...........> wrote:

Hello Meredith lamb,

Ther= e is one other question I may ask ;

Have you ever tried a torsion sp= ring
with this design ?

I have tried using an aluminum alloy
antenna e= lement that is a tube split down
the middle with a slot its full length.=
It seems to act as a spring quite well
but not sure if its actually = suitable for the job.
It would totally eliminate the bulky extension spring.

=A0

*** No I've not tried a torsion spring; but I get the idea.=A0=A0 = I think I'd rather stick with the traditional

extension spring route for the time being.

If you wish= to derive the spring constant
you can hang a water bottle with a measur= ed
amount of water to get enough weight to
extend the spring maybe 10 inche= s then use
a bit of math. You may control the overall temp
of a worki= ng device ( I think two devices are necessary
to be proper ) by placing = gallon jugs of salt
water brine surrounding the devices to make a thermal
inertia to average= out temp changes or so
I believe.

I think any linear constant ex= tension spring made out of
steel can do the right job if you can get at = least
11 or more inches of extension.

=A0

*** It entirely depends on the spring used of course.=A0 The original = cut Georgia tech spring (unloaded) was 4" length;

and loaded it "looks" like ~ its perhaps 8".=A0=A0

You must allow = for any pretensioning because
that will have an effect on its overall ex= tension.
The pretensioning will work out to some added
extension amount to the me= asured results.
Sort of a second degree correction factor
to think ab= out. That is how much water weight before
spring shows first signs of ex= tension.

=A0

*** I think a simple adequate weight scale would work to derive such a= nd about any kind

of add on weight.

No reason you c= an not easily work out the spring constant
for amateur needs.

=A0

*** I'll give it a go.

I like your Geo= rgia Design But would absolutely need two
such sensors for a complete wh= ole.

=A0

*** You mentioned measuring tilt that way earlier; but I don't thi= nk its that=A0necessary.

Please use eye = protection, I blinded
myself in one eye accidentally
with a wild spri= ng once, thank
goodness it lasted only a few seconds
before returning to normal.
Spr= ings can be dangerous to anyone's
quality of life. No one is mistake= free.

=A0

*** Yes, I've also been "bitten", whacked or cut=A0a few= times

Also Century Sp= ring Company, they will build custom
springs but charge a terrible initi= al setup fee of a
few hundred dollars I think. You want to have
maybe a hundred springs ma= de all at once.

=A0

=A0*** I won't be in production; I'd rather find/use something= already on the common hardware market.

=A0

=A0=A0=A0
Regards;

Geoff

*** Take care, Meredith Lamb
Subject: Re: which seismometer? From: "Les LaZar" llazar@.................. Date: Sat, 25 Jul 2009 00:19:05 -0700 Hi Jim, We have been thinking about a vertical version of the VolksMeter for = some time. The differential capacitive sensor would work fine in a = vertical, as would the pivot technology and the eddy damper. The = problem, as has been much talked about here, is cost-effective thermal = compensation for the spring. A vertical VolksMeter needs to be as = precise (and maintenance-free) as the current horizontal instrument. = While force-feedback would work, it would likely be too costly for the = VolksMeter market niche ($1000-$2000 selling price). Dr. Peters, the = brains behind the VolksMeter, has been looking into a bi-metal strip = that would add tension to the spring as the temperature goes up (and the = spring otherwise lengthens) but, as you might imagine, designing a = bi-metal strip that exactly compensates the spring is a challenge. Zero = tc springs are possible, but too costly in the volumes we need. Designing a product for production is always an exercise in tradeoffs = and compromises. I would welcome any suggestions. Regards, Les LaZar RLL Instruments / a division of Zoltech Corporation 818-780-1800 ----- Original Message -----=20 From: Jim ODonnell=20 To: psn-l@................. Sent: Friday, July 24, 2009 6:53 PM Subject: Re: which seismometer? Hi All- Observations of the RLL: For the last year I have been comparing Larry=92s sensors to his RLL = (Volksmeter- .lctst & .lctst1) and the results are rather outstanding. = I live close to Las Vegas so record mostly local events with 1 Hz & 4.5 = Hz geophones. But I have been considering the RLL as it gets them = all=85.Local, Regional, & Teleseismic. It is a Horizontal & I like to look at Rayleigh waves which are = predominately Z. Any chance of a RLL in Z??? <<<< Jim Jim O'Donnell- Geophysical Consultant/Contractor Geotechnical/Geothermal/Oil & Gas/Mining Applications Seismic Surveys- Surface Waves, Refraction, & Reflection Ground Penetrating Radar, Resistivity, Magnetic, & VLF-EM Surveys Geophysics@.......... 702.293.5664 702.281.9081 cell =20 Boulder City, NV ---------- Original Message ---------- From: "Les LaZar" To: Subject: Re: which seismometer? Date: Fri, 24 Jul 2009 16:36:01 -0700 Hi Jay, At the risk of tooting my own horn... If your budget is flexible, you don't specifically need a Lehman type = design=20 and your application would benefit from a research-quality instrument, = you=20 may wish to consider the RLL Instruments VolksMeter II (=20 http://www.rllinstruments.com ). Many of these are currently being = used in=20 educational and research applications. Some are in use by psn = members. If you are interested, I would be happy to answer any questions you = might=20 have. Regards, Les LaZar RLL Instruments / a division of Zoltech Corporation 818-780-1800 ----- Original Message -----=20 From: "Jay Muza" To: Sent: Friday, July 24, 2009 2:23 PM Subject: which seismometer? Hi I would like to purchase one of the inexpensive Lehman type = seismometers=20 currently on the market. The three I am considering are the AS-1, the = UK=20 School of Seismology SEP Seismometer System, and the Rockwave HS-3. = Any=20 guidance..any at all...would be greatly appreciated. Thank you. Dr. Jay Muza Department of Physical Sciences Broward College Davie, FL 33314 Office: 954.201.6771 Cell: 954.736.8231 jmuza@........... Please Note: Due to Florida's very broad public records law, most = written=20 communications to or from College employees regarding College business = are=20 public records, available to the public and media upon request. = Therefore,=20 this email communication may be subject to public disclosure. Please consider the environment before printing this email. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with=20 the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
Hi Jim,

We have been thinking about a vertical = version of=20 the VolksMeter for some time. The differential capacitive sensor = would=20 work fine in a vertical, as would the pivot technology and the eddy=20 damper. The problem, as has been much talked about here, is=20 cost-effective thermal compensation for the = spring. A=20 vertical VolksMeter needs to be as precise (and maintenance-free) as the = current=20 horizontal instrument. While force-feedback would work, it would = likely be=20 too costly for the VolksMeter market niche ($1000-$2000 selling = price). =20 Dr. Peters, the brains behind the VolksMeter, has been looking into a = bi-metal=20 strip that would add tension to the spring as the temperature goes up = (and the=20 spring otherwise lengthens) but, as you might imagine, designing a = bi-metal=20 strip that exactly compensates the spring is a challenge. Zero tc = springs=20 are possible, but too costly in the volumes we need.

Designing a product for production is = always an=20 exercise in tradeoffs and compromises.   I would welcome = any=20 suggestions.

Regards,

Les LaZar

RLL Instruments / a division of Zoltech = Corporation

818-780-1800

----- Original Message -----
From:=20 Jim=20 ODonnell

To: psn-l@..............

Sent: Friday, July 24, 2009 = 6:53 PM

Subject: Re: which = seismometer?

Hi All-
Observations of = the RLL:
For=20 the last year I have been comparing Larry=92s sensors to his RLL=20 (Volksmeter- .lctst & .lctst1) and the results are = rather=20 outstanding. I = live=20 close to Las Vegas so record mostly local events with 1 Hz & = 4.5 Hz=20 geophones. But I have = been=20 considering the RLL as it gets them all=85.Local, Regional, &=20 Teleseismic.
It is a Horizontal & I like to look at Rayleigh = waves=20 which are predominately Z.
Any chance of a RLL in=20 Z???
<<<<    Jim

Jim = O'Donnell-=20 Geophysical Consultant/Contractor
Geotechnical/Geothermal/Oil & = Gas/Mining Applications
Seismic Surveys- Surface Waves, Refraction, = &=20 Reflection
Ground Penetrating Radar, Resistivity, Magnetic, & = VLF-EM=20 Surveys
Geophysics@.......... 702.293.5664 702.281.9081 = cell=20
Boulder City, NV

---------- Original = Message=20 ----------
From: "Les LaZar" = <llazar@..................>
To:=20 <psn-l@..............>
Subject: Re: which = seismometer?
Date: Fri,=20 24 Jul 2009 16:36:01 -0700

Hi Jay,

At the risk of = tooting my own=20 horn...

If your budget is flexible, you don't specifically need = a=20 Lehman type design
and your application would benefit from a=20 research-quality instrument, you
may wish to consider the RLL = Instruments=20 VolksMeter II (
http://www.rllinstruments.com ). Many of = these are=20 currently being used in
educational and research applications. = Some=20 are in use by psn members.

If you are interested, I would be = happy to=20 answer any questions you might
have.

Regards,

Les=20 LaZar
RLL Instruments / a division of Zoltech=20 Corporation
818-780-1800

----- Original Message ----- =
From: "Jay=20 Muza" <jmuza@...........>
To: = <psn-l@..............>
Sent:=20 Friday, July 24, 2009 2:23 PM
Subject: which=20 seismometer?

Hi
I would like to purchase one of the = inexpensive=20 Lehman type seismometers
currently on the market. The three = I am=20 considering are the AS-1, the UK
School of Seismology SEP = Seismometer=20 System, and the Rockwave HS-3. Any
guidance..any at = all...would be=20 greatly appreciated. Thank you.

Dr. Jay = Muza
Department of=20 Physical Sciences
Broward College
Davie, FL = 33314

Office:=20 954.201.6771
Cell:=20    954.736.8231

jmuza@...........

Please = Note:=20 Due to Florida's very broad public records law, most written=20
communications to or from College employees regarding College = business are=20
public records, available to the public and media upon request. = Therefore,=20
this email communication may be subject to public=20 disclosure.

Please consider the environment before printing = this=20 = email.

__________________________________________________________<= BR>
Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email=20 PSN-L-REQUEST@.............. with
the body of the message (first = line=20 only): unsubscribe
See http://www.seismicnet.com/maillist.html for = more=20 = information.

_____________________________________________= _____________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email=20 PSN-L-REQUEST@.............. with
the body of the message (first = line=20 only): unsubscribe
See http://www.seismicnet.com/maillist.html for = more=20 information.
Subject: Re: Video of a experimental pivot From: "Geoffrey" gmvoeth@........... Date: Sat, 25 Jul 2009 06:41:04 -0700 Hello Mr. Lamb, > > I like your Georgia Design But would absolutely need two > such sensors for a complete whole. > *** You mentioned measuring tilt that way earlier; but I don't think its that necessary. ### I once had a regular old pendulum set up without a damper and this big septic truck came by maybe 100 ft away and set it swinging maybe an inch or so. I must be on relatively soft ground and believe two such devices of yours oriented in opposite directions could cancel out such tilts and see only vertical motion. Vehicles seem to make a dimple in the ground everywhere they go around here. Sort of like they show those black holes do with gravity. :-) Have you ever seen that old old movie (1960s) called the "Undertaker and His Pals" ? They were a bunch of bikers that ran a restaurant and they would slaughter humans and the main plate of the day was "Breast of Chicken" or "Leg of Lamb" depending on the unfortunate persons last name. People would sit down to a good portion of meat on their plate but when they tasted it ????? ### Regards; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Video of a experimental pivot From: ChrisAtUpw@....... Date: Sat, 25 Jul 2009 11:14:46 EDT In a message dated 25/07/2009, gmvoeth@........... writes: > I like your Georgia Design But would absolutely need two such sensors for a complete whole. *** You mentioned measuring tilt that way earlier; but I don't think its that necessary. Hi Geoff, You CAN'T cancel out tilt variations in vertical sensors by just using two identical instruments! You can do it using a seismometer AND a pure tiltmeter. Regards, Chris Chapman

In a message dated 25/07/2009, gmvoeth@........... writes:

> I like your Georgia Design But would absolutely need two such sensors= for a complete whole.

*** You mentioned measuring tilt that way earlier= ; but I don't think its that necessary.

Hi Geoff,

    You CAN'T cancel out tilt variations in verti= cal sensors by just using two identical instruments!

    You can do it using a seismometer AND a pure= tiltmeter.

    Regards,

    Chris Chapman
Subject: Re: Video of a experimental pivot From: Brett Nordgren brett3nt@............. Date: Sat, 25 Jul 2009 12:37:49 -0400 Chris, Why not? Can't you just orient them in opposite directions? Vertical motions should add, while tilt accelerations will subtract. That's what we do when we want to evaluate the magnitude of tilt-rotation noise on Dave's verticals. Obviously DC tilts don't necessarily cancel, but I wouldn't expect that to be the primary problem. Come to think of it, wouldn't you even be able to cancel steady-state tilts if you adjusted one vertical instrument slightly off-center in one direction and the opposing one the same amount in the opposite direction? Brett At 11:14 AM 7/25/2009 -0400, you wrote: >In a message dated 25/07/2009, gmvoeth@........... writes: >> > I like your Georgia Design But would absolutely need two such sensors >> for a complete whole. >> >>*** You mentioned measuring tilt that way earlier; but I don't think its >>that necessary. >Hi Geoff, > > You CAN'T cancel out tilt variations in vertical sensors by just > using two identical instruments! > You can do it using a seismometer AND a pure tiltmeter. > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: which seismometer? From: meredith lamb paleoartifact@......... Date: Sat, 25 Jul 2009 11:18:07 -0600 Dr. Muza, With the "assumption" that of the 3, you mention; you are looking for a "classroom demonstrator" that is only used for "light/cursory" education....I'd suggest the SEP. Its a simple coil and magnet induction setup; but looks very long term reliable and well structurally designed and made. It would likely require simple screw tilt or centering seasonal adjustments once in awhile. It has free web programs and seems to have great recommendations, many affiliated educational stations, and apparently many volunteers that help enhance its use. The Rockwave would be my second choice. It is a lot more technically involved via capacitive pickup and feedback and computer programs. Unfortunately; I do not know how really reliable it is overall, as from looking outside of the Rockwave web site, I've found no bad references as too reliability....which thus far appears to be a good sign. It would appear to be capable for more advanced studies...if....that is part of your plan and/or evolves eventually for you or your students. Both the above seem to be around the same price range and are intermediate to long period horizontals that will likely pick up significant quake phases around the world. The AS-1 is a older design and generally limited to "P" quake phase short period vertical signals. It won't be able to pick up the long range "S" and "L" teleseismic large magnitude quake surface wave phase signals from around the world, that the first two will much more easily do. I have none of the three....this is only my limited personal opinion. Meredith Lamb On Fri, Jul 24, 2009 at 3:23 PM, Jay Muza wrote: > Hi > I would like to purchase one of the inexpensive Lehman type seismometers > currently on the market. The three I am considering are the AS-1, the UK > School of Seismology SEP Seismometer System, and the Rockwave HS-3. Any > guidance..any at all...would be greatly appreciated. Thank you. > > > Dr. Jay Muza > Department of Physical Sciences > Broward College > Davie, FL 33314 > > Office: 954.201.6771 > Cell: 954.736.8231 > > jmuza@........... > > Please Note: Due to Florida's very broad public records law, most written > communications to or from College employees regarding College business are > public records, available to the public and media upon request. Therefore, > this email communication may be subject to public disclosure. > > Please consider the environment before printing this email. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
Dr. Muza,

=A0

With the "assumption" that of the 3, you mention; you are lo= oking for a "classroom demonstrator" that is only

used for "light/cursory" education....I'd suggest the SE= P.=A0 Its a simple coil and magnet induction setup; but looks very long
term reliable and well structurally designed and made.=A0 It would lik= ely require simple screw tilt or centering seasonal adjustments once in awh= ile.=A0 It has free=A0web programs and seems to have great recommendations,= =A0many affiliated educational stations, and apparently many volunteers tha= t help enhance its use.=A0

=A0

The Rockwave would be my second choice.=A0 It is a lot more technicall= y involved via capacitive pickup and feedback and

computer programs.=A0 Unfortunately; I do not know how really reliable= it is overall, as from looking outside of the Rockwave web site, I've = found no bad references as too reliability....which thus far appears to=A0b= e a good sign.=A0 It would appear to be

capable for more advanced studies...if....that is part of your plan an= d/or evolves eventually for you or your students.

=A0

Both the=A0above seem to be around the same price range and are interm= ediate to long period horizontals that will likely

pick up significant quake phases=A0around the world.=A0

=A0

The AS-1=A0is a older design and generally limited to =A0"P"= quake phase short period vertical signals.=A0=A0It=A0won't be able to = pick up the long range "S" and "L" teleseismic large ma= gnitude quake surface wave phase signals from around the world, that the fi= rst two will much more easily do.=A0

=A0

I=A0 have none of the three....this is only my limited personal opinio= n.

=A0

Meredith Lamb

=A0

=A0

=A0

=A0

=A0

=A0=A0

On Fri, Jul 24, 2009 at 3:23 PM, Jay Muza <jmuza@...........&= gt; wrote:

Hi
I would like to purchase o= ne of the inexpensive Lehman type seismometers currently on the market. =A0= The three I am considering are the AS-1, the UK School of Seismology SEP Se= ismometer System, and the Rockwave HS-3. =A0Any guidance..any at all...woul= d be greatly appreciated. =A0Thank you.

Dr. Jay Muza
Department of Physical Sciences
Broward College<= br>Davie, FL =A033314

Office: 954.201.6771
Cell: =A0 =A0954.736.8= 231

jmuza@...........
Please Note: Due to Florida's very broad public records law, most wri= tten communications to or from College employees regarding College business= are public records, available to the public and media upon request. Theref= ore, this email communication may be subject to public disclosure.

Please consider the environment before printing this email.

____= ______________________________________________________

Public Seismi= c Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
See http://www.seismic= net.com/maillist.html for more information.

Subject: Re: Video of a experimental pivot From: ChrisAtUpw@....... Date: Sat, 25 Jul 2009 14:11:07 EDT In a message dated 25/07/2009, brett3nt@............. writes: > You CAN'T cancel out tilt variations in vertical sensors by just using two identical instruments! > You CAN do it using a seismometer AND a pure tiltmeter. Why not? Can't you just orient them in opposite directions? Vertical motions should add, while tilt accelerations will subtract. That's what we do when we want to evaluate the magnitude of tilt-rotation noise on Dave's verticals. Hi Brett, That won't work! The vertical force change due to a tilt theta is mgCos(theta) = 1 - theta^3 / !3 + This is HIGHLY non linear with angle. Moreover, you get the same negative polarity force change for tilts in ANY orientation in the horizontal plane. You might want cross check your assumptions about tilt rotation noise? Obviously DC tilts don't necessarily cancel, but I wouldn't expect that to be the primary problem. Come to think of it, wouldn't you even be able to cancel steady-state tilts if you adjusted one vertical instrument slightly off-center in one direction and the opposing one the same amount in the opposite direction? Not in general. If you set up two sensors with identical offsets in opposite directions, they will both still produce a tilt error if the tilt direction is at right angles to the line joining the centres of the two instruments. You need triaxial sensors to resolve this, but you still won't know if an effect is due to a tilt, or to a horizontal acceleration. You need a pure tiltmeter to resolve this hoary ancient problem - a liquid level meter WON'T do! Regards, Chris
In a message dated 25/07/2009, brett3nt@............. writes:

>    You CAN'T cancel out tilt variation= s in vertical sensors by just using two identical instruments!
>&n= bsp;    You CAN do it using a seismometer AND a pure tiltmeter.

Why not? Can't you just orient them in opposite directions? Vertic= al motions should add, while tilt accelerations will subtract. That's what= we do when we want to evaluate the magnitude of tilt-rotation noise on Dave's= verticals.

Hi Brett,

    That won't work!

    The vertical force change due to a tilt theta= is mgCos(theta) =3D 1 - theta^3 / !3 +

    This is HIGHLY non linear with angle. Moreover, yo= u get the same negative polarity force change for tilts in ANY orientation= in the horizontal plane.

    You might want cross check your assumptions= about tilt rotation noise?

Obviously DC tilts don't necessarily cancel, but I wouldn't= expect that to be the primary problem. Come to think of it, wouldn't you= even be able to cancel steady-state tilts if you adjusted one vertical instru= ment slightly off-center in one direction and the opposing one the same amoun= t in the
opposite direction?

    Not in general. If you set up two sensors wit= h identical offsets in opposite directions, they will both still produce a= tilt error if the tilt direction is at right angles to the line joining th= e centres of the two instruments.

You need triaxial sensors to resolve this, but you still won't= know if an effect is due to a tilt, or to a horizontal acceleration. You need a pu= re tiltmeter to resolve this hoary ancient problem - a liquid level meter WON= 'T do!

    Regards,

    Chris
Subject: Re: Video of a experimental pivot From: Brett Nordgren brett3nt@............. Date: Sat, 25 Jul 2009 23:07:26 -0400 Hi Chris, First we need to distinguish between vertical force change due to a tilt theta (DC tilt) and a dynamic tilt resulting from an oscillating earth motion which rotates the instrument about its horizontal pivot axis such as you would get from trees blowing in the wind; the same sort of motion as in a Rayleigh wave. Such motion produces a rotational acceleration about the pivot generating an output signal which combines with the signal from any vertical motion. Two identical instruments oriented in opposite directions will indeed cancel this kind of error if their outputs are added. >Hi Brett, > > That won't work! > > The vertical force change due to a tilt theta is mgCos(theta) = 1 - > theta^3 / !3 + I think it is the force f which = mgCos(theta), so the rate of force change with respect to theta = df/d theta = -mgSin(theta). As theta approaches zero, -mgSin(theta) approaches -mgSin(0) = zero. The rate of force change with respect to theta approaches zero. Small DC tilts produce even smaller force changes. This seems to be confirmed in the literature: "For small tilt angles, the contribution to the vertical component is negligible" Forbriger "Low-frequency limit for H/V studies due to tilt" October, 2006 Unpublished. and "While in a precisely vertical sensor the effect of tilt is of second order and thus in most cases, negligible....." Wielandt and Forbriger, "Near-field seismic displacement......" Annali de Geofisica, June 1999 Of course with horizontal sensors it is a totally different story. Brett > This is HIGHLY non linear with angle. Moreover, you get the same > negative polarity force change for tilts in ANY orientation in the > horizontal plane. > > You might want cross check your assumptions about tilt rotation noise? >>Obviously DC tilts don't necessarily cancel, but I wouldn't expect that >>to be the primary problem. Come to think of it, wouldn't you even be >>able to cancel steady-state tilts if you adjusted one vertical instrument >>slightly off-center in one direction and the opposing one the same amount >>in the >>opposite direction? > Not in general. If you set up two sensors with identical offsets in > opposite directions, they will both still produce a tilt error if the > tilt direction is at right angles to the line joining the centres of the > two instruments. >You need triaxial sensors to resolve this, but you still won't know if an >effect is due to a tilt, or to a horizontal acceleration. You need a pure >tiltmeter to resolve this hoary ancient problem - a liquid level meter >WON'T do! __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Would Any Of Yous Guts Believe This ? From: "Geoffrey" gmvoeth@........... Date: Sat, 1 Aug 2009 05:02:54 -0700 Hello All you Happy face PSN folks; I think I just received a pP signal from a 5.0 Japanese quake with my SPZ sensor and I'm over 80 deg away. Sure the signal is buried in the grass and hard to see. But, you can definitely hear it as a wave file and see it in the Audacity FFT routine. I can also see and measure a time to within one second of arrival time from Winquake. TUC station shown nothing but still I think this is what I see. Does anyone else in the USA concur that they have seen this signal. pP_09:58:06_2009AUG01_UTC Usually they must be at least 5.5 for me to see them this far away. 80+ degrees Regards geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Brett Nordgren brett3nt@............. Date: Sat, 01 Aug 2009 08:48:03 -0400 Geoff, Yes, we can clearly see it on two verticals located south of LA. Looks like the LR arrives there around 10:21+ UTC which matches with the Honshu 5.0. When filtered 0,002 - 0.08 the peak energy is at around 22sec and peak amplitude is around 50nm/s, which is only a little over 5 counts for us. The background peaks are around 2-3 counts. This is one of the smallest we have seen, too, though I think that in the past we may have seen a couple at about 90 degrees in the high 4's. Regards, Brett At 05:02 AM 8/1/2009 -0700, you wrote: >Hello All you Happy face PSN folks; > >I think I just received a pP signal >from a 5.0 Japanese quake with >my SPZ sensor and I'm over >80 deg away. Sure the signal >is buried in the grass and >hard to see. But, you can >definitely hear it as a wave file >and see it in the Audacity FFT routine. >I can also see and measure a time >to within one second of arrival >time from Winquake. TUC station >shown nothing but still I think >this is what I see. > >Does anyone else in the USA concur >that they have seen this signal. > >pP_09:58:06_2009AUG01_UTC > >Usually they must be at least 5.5 >for me to see them this far away. > >80+ degrees > >Regards >geoff >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Thomas Dick dickthomas01@............. Date: Sat, 01 Aug 2009 09:36:38 -0500 Geoffrey wrote: > Hello All you Happy face PSN folks; > > I think I just received a pP signal > from a 5.0 Japanese quake with > my SPZ sensor and I'm over > 80 deg away. > I am at 92 degrees. Yes lots of noise. Not doing audio but on the vertical could the pP actually be a PcP or P? And did you get a peak at the arrival (sharp peak) of SS and LQ ... could the complex of waves at the arrival of S be due to the depth of the quake ... to a lesser extent, there are peaks on the E-W Lehman but not the N-S. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: "Geoffrey" gmvoeth@........... Date: Sat, 1 Aug 2009 09:16:21 -0700 ----- Original Message ----- From: "Thomas Dick" To: Sent: Saturday, August 01, 2009 7:36 AM Subject: Re: Would Any Of Yous Guts Believe This ? Geoffrey wrote: > Hello All you Happy face PSN folks; > > I think I just received a pP signal > from a 5.0 Japanese quake with > my SPZ sensor and I'm over > 80 deg away. > I am at 92 degrees. Yes lots of noise. Not doing audio but on the vertical could the pP actually be a PcP or P? And did you get a > peak at the arrival (sharp peak) of SS and LQ ... could the complex of waves at the arrival of S be due to the depth of the quake > ... to a lesser extent, there are peaks on the E-W Lehman but not the N-S. > I can not see the signal with my own eyes and no processing. It only looks like the rest of the noise. When i convert to a WAV file I can easily hear what I can not see. When I do an fft, I can see it too in Audacity. I go the time frame and filter in Winquake I can barely get a time. But Although my time is not good enough to report to the USGS I believe I have the pP time since it matches that in theoretical arrival times at my station to within a second or so it seems. I see no other signals but what I believe to be the pP wave. My lower limit is like 23 seconds but I am only equalized partially to 12 seconds. My meaningful range is about 12 seconds to 2Hz. Not wide as yours I bet. All of you are seeing more detail than I but Im using a one second Z only device. I would like to know if any of you are seeing this on one second or SPZ devices ? Regards, geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Thomas Dick dickthomas01@............. Date: Sat, 01 Aug 2009 11:31:02 -0500 > My meaningful range is about > 12 seconds to 2Hz. Not wide as yours I bet. > All of you are seeing more detail than I > but Im using a one second Z only device. > > I would like to know if any of you are seeing this on > one second or SPZ devices ? > > see post td4aa for Evansville, IN ..note sensors __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Thomas Dick dickthomas01@............. Date: Sat, 01 Aug 2009 11:39:28 -0500 Geoffrey > Another quake coming in ... also a five ... but not as deep > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Brett Nordgren brett3nt@............. Date: Sat, 01 Aug 2009 12:52:14 -0400 Thomas and Geoff, Although we go up to 30Hz, the background noise in the area usually obliterates any small higher-frequency phases. I don't think we were seeing anything but surface waves from the Honshu quake. But...... with a10 second LoPass filter your recent Pacific 5.2 at 108 degrees from LA did show a clearly visible Pdiff and then about 18 minutes of various body phases which I don't have the experience to identify, followed by some big surface waves. What does your noise level look like, Thomas? Brett At 09:36 AM 8/1/2009 -0500, you wrote: >Geoffrey wrote: >>Hello All you Happy face PSN folks; >> >>I think I just received a pP signal >>from a 5.0 Japanese quake with >>my SPZ sensor and I'm over >>80 deg away. > >I am at 92 degrees. Yes lots of noise. Not doing audio but on the vertical >could the pP actually be a PcP or P? And did you get a peak at the arrival >(sharp peak) of SS and LQ ... could the complex of waves at the arrival of >S be due to the depth of the quake ... to a lesser extent, there are peaks >on the E-W Lehman but not the N-S. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Would Any Of Yous Guts Believe This ? From: Thomas Dick dickthomas01@............. Date: Sat, 01 Aug 2009 13:56:57 -0500 Brett Nordgren wrote: > Thomas and Geoff, > > Although we go up to 30Hz, the background noise in the area usually > obliterates any small higher-frequency phases. > > I don't think we were seeing anything but surface waves from the > Honshu quake. But...... with a10 second LoPass filter your recent > Pacific 5.2 at 108 degrees from LA did show a clearly visible Pdiff > and then about 18 minutes of various body phases which I don't have > the experience to identify, followed by some big surface waves. > > What does your noise level look like, Thomas? > > Brett > > At 09:36 AM 8/1/2009 -0500, you wrote: >> Geoffrey wrote: >>> Hello All you Happy face PSN folks; >>> >>> I think I just received a pP signal >>> from a 5.0 Japanese quake with >>> my SPZ sensor and I'm over >>> 80 deg away. >> >> I am at 92 degrees. Yes lots of noise. Not doing audio but on the >> vertical could the pP actually be a PcP or P? And did you get a peak >> at the arrival (sharp peak) of SS and LQ ... could the complex of >> waves at the arrival of S be due to the depth of the quake ... to a >> lesser extent, there are peaks on the E-W Lehman but not the N-S. >> > quieter than it has been for seven days > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Stationary Magnet or Stationary Coil From: "Gary Lindgren" gel@................. Date: Sat, 1 Aug 2009 12:10:53 -0700 Chris, With your Lehman http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_prototype.jpg you have a stationary magnet with the pickup coil moving through the magnet. You have also shown to use the magnet on the boom with a stationary coil. This would seem to be a better solution in that you don't have flexing wires. What are the non-obvious trade-offs. I suppose it is easier to adjust the stationary magnet approach. Anything else? Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com Check out Lastest Seismometer Reading cymonsplace.blogspot.com dtvtransitioninfo.blogspot.com Information on how to cope with the transition to DTV

Chris,

With your Lehman http://jclahr.com/science/psn/chapman/2008%20lehman/lehman_proto= type.jpg   you have a stationary magnet with the pickup coil moving through the = magnet. You have also shown to use the magnet on the boom with a stationary coil. = This would seem to be a better solution in that you don’t have flexing = wires. What are the non-obvious trade-offs. I suppose it is easier to adjust the = stationary magnet approach. Anything else?

Gary

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

650-326-0655<= /span>

www.blue-eagle-technologies.com &nbs= p; Check out Lastest Seismometer = Reading

cymonsplace.blogspot.com =

dtvtransitioninfo.blogspot.com  = ;      Information on how to cope with the transition = to DTV

Subject: Large Response Coming in Now at 18:00 UTC From: "Gary Lindgren" gel@................. Date: Mon, 3 Aug 2009 11:13:58 -0700 I just noticed a very strong response coming in now p wave at 18:00:54 UTC. Shows up on Lehman only no vertical response. Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com Check out Lastest Seismometer Reading cymonsplace.blogspot.com dtvtransitioninfo.blogspot.com Information on how to cope with the transition to DTV

I just noticed a very strong response coming in now = p wave at 18:00:54 UTC. Shows up on Lehman only no vertical = response.

Gary

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

650-326-0655<= /span>

www.blue-eagle-technologies.com &nbs= p; Check out Lastest Seismometer = Reading

cymonsplace.blogspot.com =

dtvtransitioninfo.blogspot.com  = ;      Information on how to cope with the transition = to DTV

Subject: Re: Large Response Coming in Now at 18:00 UTC From: Canie canie@........... Date: Mon, 03 Aug 2009 11:21:56 -0700 I see a 6.9 in the Gulf of California.. http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/at00932240.php Canie At 11:13 AM 8/3/2009, you wrote: >I just noticed a very strong response coming in now p wave at >18:00:54 UTC. Shows up on Lehman only no vertical response. >Gary > > > > > > >Gary Lindgren >585 Lincoln Ave >Palo Alto CA 94301 > >650-326-0655 > >www.blue-eagle-technologies.com >Check out Lastest Seismometer Reading >cymonsplace.blogspot.com >dtvtransitioninfo.blogspot.com >Information on how to cope with the transition to DTV > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: Bob Hancock icarus@......... Date: Mon, 3 Aug 2009 11:28:50 -0700 There are two events, the first one if listed as M 5.8, the second event is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 mm on the North channel, and 2.0 mm of movement on East channel. My station is only 3.43 degrees (381.14 km) from the event. Bob Hancock On Aug 3, 2009, at 11:13 AM, Gary Lindgren wrote: > I just noticed a very strong response coming in now p wave at > 18:00:54 UTC. Shows up on Lehman only no vertical response. > Gary > > > > > > > Gary Lindgren > 585 Lincoln Ave > Palo Alto CA 94301 > > 650-326-0655 > > www.blue-eagle-technologies.com Check out Lastest Seismometer > Reading > cymonsplace.blogspot.com > dtvtransitioninfo.blogspot.com Information on how to cope > with the transition to DTV > >
There are two events, the = first one if listed as M 5.8, the second event is M 6.9. I = recorded 2.6 mm of movement on the vertical channel, 3.8 mm on the North = channel, and 2.0 mm of movement on East channel. My station is = only 3.43 degrees (381.14 km) from the = event.

Bob = Hancock

On Aug 3, 2009, at 11:13 AM, = Gary Lindgren wrote:

I just noticed a very strong = response coming in now p wave at 18:00:54 UTC. Shows up on Lehman only = no vertical response.
Gary

Gary Lindgren585 = Lincoln Ave
Palo = Alto CA 94301

  Information on how to cope with the transition to = DTV

I have a nice trace here in San Jose, CA. On = my website now: www.rowelabs.com

Pete

--- On Mon, 8/= 3/09, Bob Hancock <icarus@.........> wrote:

From: Bob Hancock <icarus@.........>
Subject: Re= : Large Response Coming in Now at 18:00 UTC
To: psn-l@..............
= Date: Monday, August 3, 2009, 11:28 AM

There are two events, the first one if listed as M 5.8, the second event = is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 = mm on the North channel, and 2.0 mm of movement on East channel. My s= tation is only 3.43 degrees (381.14 km) from the event.

Bob Hancock

On Aug 3, 2009, at 11:1= 3 AM, Gary Lindgren wrote:

I just noticed a very stron= g response coming in now p wave at 18:00:54 UTC. Shows up on Lehman only no= vertical response.
Gary
<= /div>

Gary Lindgren
585 Lincoln Ave
Pal= o Alto CA 94301

<= span style=3D"font-size: 10pt; font-family: Arial,sans-serif;">650-326-0655=

www.blue-eagle-t= echnologies.com   Check out Lastest Seismometer Rea= ding
cymonsplace.blogspot.com<= /a>
dtvtransitioninfo.blogspot.com    &n= bsp;   Information on how to cope with the transition to DTV

=

=0A=0A Subject: Re: Large Response Coming in Now at 18:00 UTC From: "tchannel" tchannel@............ Date: Mon, 3 Aug 2009 12:43:08 -0600 Both events arrived big-time in Eagle = Idaho..........ll.........llll......... Ted ----- Original Message -----=20 From: Pete Rowe=20 To: psn-l@................. Sent: Monday, August 03, 2009 12:31 PM Subject: Re: Large Response Coming in Now at 18:00 UTC I have a nice trace here in San Jose, CA. On my website now: = www.rowelabs.com Pete --- On Mon, 8/3/09, Bob Hancock wrote: From: Bob Hancock Subject: Re: Large Response Coming in Now at 18:00 UTC To: psn-l@.............. Date: Monday, August 3, 2009, 11:28 AM There are two events, the first one if listed as M 5.8, the = second event is M 6.9. I recorded 2.6 mm of movement on the vertical = channel, 3.8 mm on the North channel, and 2.0 mm of movement on East = channel. My station is only 3.43 degrees (381.14 km) from the event. Bob Hancock On Aug 3, 2009, at 11:13 AM, Gary Lindgren wrote: I just noticed a very strong response coming in now p wave = at 18:00:54 UTC. Shows up on Lehman only no vertical response. Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com Check out Lastest = Seismometer Reading cymonsplace.blogspot.com=20 dtvtransitioninfo.blogspot.com Information on how to = cope with the transition to DTV =20
Both events arrived big-time in Eagle=20 Idaho..........ll.........llll.........

Ted

----- Original Message -----
From:=20 Pete = Rowe

To: psn-l@..............

Sent: Monday, August 03, 2009 = 12:31=20 PM

Subject: Re: Large Response = Coming in Now=20 at 18:00 UTC

I have a nice trace here in San Jose, CA. On my = website=20 now: www.rowelabs.com

Pete

= ---=20 On Mon, 8/3/09, Bob Hancock <icarus@.........>=20 wrote:

From:=20 Bob Hancock <icarus@.........>
Subject:=20 Re: Large Response Coming in Now at 18:00 UTC
To: psn-l@..............
Date:=20 Monday, August 3, 2009, 11:28 AM

There are two events, the first one if listed as M 5.8, = the=20 second event is M 6.9. I recorded 2.6 mm of movement on = the=20 vertical channel, 3.8 mm on the North channel, and 2.0 mm of = movement=20 on East channel. My station is only 3.43 degrees (381.14 = km)=20 from the event.

Bob Hancock

On Aug 3, 2009, at 11:13 AM, Gary Lindgren = wrote:

I=20 just noticed a very strong response coming in now p wave at = 18:00:54=20 UTC. Shows up on Lehman only no vertical response.
Gary

Gary=20 Lindgren 585=20 Lincoln Ave Palo=20 Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com   Check out Lastest Seismometer=20 Reading cymonsplace.blogspot.com dtvtransitioninfo.blogspot.com    &n= bsp;   Information on how to cope with the = transition to=20 DTV

Subject: Re: Large Response Coming in Now at 18:00 UTC From: JAMES RIDOUT jamesridout@.............. Date: Mon, 3 Aug 2009 18:53:44 +0000 (GMT) Getting it now in the UK, Large surface waves. --- On Mon, 3/8/09, tchannel wrote: From: tchannel Subject: Re: Large Response Coming in Now at 18:00 UTC To: psn-l@.............. Date: Monday, 3 August, 2009, 7:43 PM Both events arrived big-time in Eagle Idaho..........ll.........llll.......= ... Ted ----- Original Message -----=20 From: Pete Rowe=20 To: psn-l@................. Sent: Monday, August 03, 2009 12:31 PM Subject: Re: Large Response Coming in Now at 18:00 UTC I have a nice trace here in San Jose, CA. On my website now:=A0 www.rowelab= s.com Pete --- On Mon, 8/3/09, Bob Hancock wrote: From: Bob Hancock Subject: Re: Large Response Coming in Now at 18:00 UTC To: psn-l@.............. Date: Monday, August 3, 2009, 11:28 AM There are two events, the first one if listed as M 5.8, the second event is= M 6.9. =A0I recorded 2.6 mm of movement on the vertical channel, 3.8 mm on= the North channel, and 2.0 mm of movement on East channel. =A0My station i= s only 3.43 degrees (381.14 km) from the event. Bob Hancock On Aug 3, 2009, at 11:13 AM, Gary Lindgren wrote: I just noticed a very strong response coming in now p wave at 18:00:54 UTC.= Shows up on Lehman only no vertical response. Gary =A0 =A0 =A0 =A0 =A0 =A0 Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 =A0 650-326-0655 =A0 www.blue-eagle-technologies.com=A0=A0=A0Check out Lastest Seismometer Readi= ng cymonsplace.blogspot.com=A0 dtvtransitioninfo.blogspot.com=A0=A0=A0=A0=A0=A0=A0=A0Information on how to= cope with the transition to DTV =A0 =A0
Getting it now in the UK, Large surface waves= ..

--- On Mon, 3/8/09, tchannel <tchannel@............> wrote:

From: tchannel <tchannel@............>
S= ubject: Re: Large Response Coming in Now at 18:00 UTC
To: psn-l@webtroni= cs.com
Date: Monday, 3 August, 2009, 7:43 PM

Both events arrived big-time in Eagle Idah= o..........ll.........llll.........

Ted

----- Original Message -----

From: Pete Rowe

To: ps= n-l@..............

Sent: Monday, August 03, 2009 12:31 = PM

Subject: Re: Large Response Coming i= n Now at 18:00 UTC

I have a nice trace here in San Jose, CA. On my website no= w: www.rowelabs.com

Pete

--- On Mon, 8/3/09, Bob Hancoc= k <icarus@.........> wrote:

From: Bob Hancock <icarus@.........>
Subjec= t: Re: Large Response Coming in Now at 18:00 UTC
To: psn-l@............. om
Date: Monday, August 3, 2009, 11:28 AM

There are two events, the first one if listed as M 5.8, the second eve= nt is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3= ..8 mm on the North channel, and 2.0 mm of movement on East channel. M= y station is only 3.43 degrees (381.14 km) from the event.

Bob Hancock

On Aug 3, 2009, at 11:13 AM, Gary Lindgren wrote:

I just noticed a very strong response coming in now p wave at 18= :00:54 UTC. Shows up on Lehman only no vertical response.

Gary

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

= 650-326-0655

= www.blue-eagle-technologies.com Check out= Lastest Seismometer Reading

= cymonsplace.blogspot.com

= dtvtransitioninfo.blogspot.com = Information on how to cope with the transition to DTV

Subject: Re: Large Response Coming in Now at 18:00 UTC From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 03 Aug 2009 19:09:30 +0000 Hi This event did appear on my Lehman type sensor, cleary for a change. But I do need better magnets. :) Regards. J=F3n Fr=EDmann. On m=E1n, 2009-08-03 at 18:53 +0000, JAMES RIDOUT wrote: > Getting it now in the UK, Large surface waves. >=20 > --- On Mon, 3/8/09, tchannel wrote: > =20 > From: tchannel > Subject: Re: Large Response Coming in Now at 18:00 UTC > To: psn-l@.............. > Date: Monday, 3 August, 2009, 7:43 PM > =20 > Both events arrived big-time in Eagle > Idaho..........ll.........llll......... > Ted > ----- Original Message -----=20 > From: Pete Rowe=20 > To: psn-l@................. > Sent: Monday, August 03, 2009 12:31 PM > Subject: Re: Large Response Coming in Now at 18:00 UTC > =20 > =20 > I have a nice trace here in San Jose, CA. On my > website now: www.rowelabs.com > =20 > Pete > =20 > --- On Mon, 8/3/09, Bob Hancock > wrote: > =20 > From: Bob Hancock > Subject: Re: Large Response Coming in Now at > 18:00 UTC > To: psn-l@.............. > Date: Monday, August 3, 2009, 11:28 AM > =20 > There are two events, the first one if listed > as M 5.8, the second event is M 6.9. I > recorded 2.6 mm of movement on the vertical > channel, 3.8 mm on the North channel, and 2.0 > mm of movement on East channel. My station is > only 3.43 degrees (381.14 km) from the event. > =20 > =20 > Bob Hancock > =20 > =20 > =20 > On Aug 3, 2009, at 11:13 AM, Gary Lindgren > wrote: > =20 > > I just noticed a very strong response coming > > in now p wave at 18:00:54 UTC. Shows up on > > Lehman only no vertical response. > > Gary > > =20 > > =20 > > =20 > > =20 > > =20 > > =20 > > Gary Lindgren > > 585 Lincoln Ave > > Palo Alto CA 94301 > > =20 > > 650-326-0655 > > =20 > > www.blue-eagle-technologies.com Check out > > Lastest Seismometer Reading > > cymonsplace.blogspot.com=20 > > dtvtransitioninfo.blogspot.com Informati= on on how to cope with the transition to DTV > > =20 > > =20 > =20 > =20 > =20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: Brett Nordgren brett3nt@............. Date: Mon, 03 Aug 2009 15:39:02 -0400 It was pretty strong at the vertical near LA. Used 20% of full-scale on the low gain channel (2V out of 10V). Posted at: http://bnordgren.org/seismo/090803.175000.bhz-pl.psn.gif Brett At 11:13 AM 8/3/2009 -0700, you wrote: >I just noticed a very strong response coming in now p wave at 18:00:54 >UTC. Shows up on Lehman only no vertical response. > >Gary __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: "Edward Ianni" edwianni1@........... Date: Mon, 03 Aug 2009 20:01:46 +0000 Large Response(s) received approximately 18: 06 in NJ ( on 2 Horizontals = (E-W, N-S), and 1 Vertical). ED.=20 ----- Original Message -----=20 From: Gary Lindgren=20 To: psn-l@................. Sent: Monday, August 03, 2009 6:13 PM Subject: Large Response Coming in Now at 18:00 UTC I just noticed a very strong response coming in now p wave at 18:00:54 = UTC. Shows up on Lehman only no vertical response. Gary =20 =20 =20 =20 =20 =20 Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 =20 650-326-0655 =20 www.blue-eagle-technologies.com Check out Lastest Seismometer = Reading cymonsplace.blogspot.com=20 dtvtransitioninfo.blogspot.com Information on how to cope with = the transition to DTV=20 =20 =20 -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.392 / Virus Database: 270.13.42/2279 - Release Date: = 08/03/09 05:57:00
Large Response(s) received = approximately 18:=20 06 in NJ ( on 2 Horizontals (E-W, N-S), and 1 Vertical). =20 ED.

----- Original Message -----
From:=20 Gary=20 Lindgren

To: psn-l@..............

Sent: Monday, August 03, 2009 = 6:13=20 PM

Subject: Large Response Coming = in Now at=20 18:00 UTC

I just noticed a very strong response coming in = now p wave=20 at 18:00:54 UTC. Shows up on Lehman only no vertical = response.

Gary

Gary=20 Lindgren

585=20 Lincoln Ave

Palo=20 Alto CA 94301

650-326-0655

www.blue-eagle-technologies.com  =20 Check out Lastest Seismometer=20 Reading

cymonsplace.blogspot.com

dtvtransitioninfo.blogspot.com    &n= bsp;  =20 Information on how to cope with the = transition to=20 DTV

No virus found in this incoming message.
Checked by AVG = -=20 www.avg.com
Version: 8.5.392 / Virus Database: 270.13.42/2279 - = Release=20 Date: 08/03/09 05:57:00
Subject: Re: Would Any Of Yous Guts Believe This ? From: "Geoffrey" gmvoeth@........... Date: Mon, 3 Aug 2009 14:37:46 -0700 Thanks you guys, very much. Best regards geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: audun@........... Date: Tue, 4 Aug 2009 01:09:34 +0200 (CEST) The quake shows very nicely here in Norway on my SEP. LP 1Hz http://vindkast.no/wpblogg/ Audun Fikke __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: Brett Nordgren brett3nt@............. Date: Mon, 03 Aug 2009 19:56:52 -0400 Bob Now that I corrected the y-scale the plot from our vertical http://bnordgren.org/seismo/090803.175000.bhz-pl.psn.gif shows roughly 3mm/s peak, which agrees pretty well with the values (assuming you meant mm/s) that you were seeing. This is from near LA which is at about 6.5 deg. It's interesting that if you assume the predominant frequency was 1/13 seconds, that should imply that the vertical ground motion at Dave's vault was about 6.2mm peak or 1.24 cm p-p. That's a lot of motion! For laughs, I uploaded the output from the high gain channel http://bnordgren.org/seismo/090803.175000.bhz-ph.psn.gif which clips at 300um/s and indeed it clipped. However, the low gain channel should be able to handle up to 1.5cm/sec peak. Brett At 11:28 AM 8/3/2009 -0700, you wrote: >There are two events, the first one if listed as M 5.8, the second event >is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 mm >on the North channel, and 2.0 mm of movement on East channel. My station >is only 3.43 degrees (381.14 km) from the event. > >Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: Brett Nordgren brett3nt@............. Date: Mon, 03 Aug 2009 20:02:51 -0400 Bob For laughs, I uploaded the output from the high gain channel http://bnordgren.org/seismo/090803.175000.bhz-ph.psn.gif Brett At 11:28 AM 8/3/2009 -0700, you wrote: >There are two events, the first one if listed as M 5.8, the second event >is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 mm >on the North channel, and 2.0 mm of movement on East channel. My station >is only 3.43 degrees (381.14 km) from the event. > >Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: "tchannel" tchannel@............ Date: Mon, 3 Aug 2009 18:28:52 -0600 Hi Brett, How do I set up WinSDR or Winquake to view as movement? ( I recorded 2.6 mm of movement on the vertical channel) Thanks, Ted ----- Original Message ----- From: "Brett Nordgren" To: Sent: Monday, August 03, 2009 5:56 PM Subject: Re: Large Response Coming in Now at 18:00 UTC > Bob > > Now that I corrected the y-scale the plot from our vertical > http://bnordgren.org/seismo/090803.175000.bhz-pl.psn.gif shows roughly > 3mm/s peak, which agrees pretty well with the values (assuming you meant > mm/s) that you were seeing. This is from near LA which is at about 6.5 > deg. It's interesting that if you assume the predominant frequency was > 1/13 seconds, that should imply that the vertical ground motion at Dave's > vault was about 6.2mm peak or 1.24 cm p-p. That's a lot of motion! > > For laughs, I uploaded the output from the high gain channel > http://bnordgren.org/seismo/090803.175000.bhz-ph.psn.gif which clips at > 300um/s and indeed it clipped. However, the low gain channel should be > able to handle up to 1.5cm/sec peak. > > Brett > > At 11:28 AM 8/3/2009 -0700, you wrote: >>There are two events, the first one if listed as M 5.8, the second event >>is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 mm >>on the North channel, and 2.0 mm of movement on East channel. My station >>is only 3.43 degrees (381.14 km) from the event. >> >>Bob Hancock > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: Brett Nordgren brett3nt@............. Date: Mon, 03 Aug 2009 21:00:27 -0400 Hi Ted, No WinQuake magic here, just used the calculator. Given that the period, P, of the largest trace was 13 seconds, which I got by measuring the surface wave in WinQuake, then Peak Displacement = Peak Velocity * Period / 2 Pi. Or in my case = 3mm/s * 13s / 2Pi = 6.2mm. That works in general, though if you had a smaller, much longer wave, it might compute to have a larger displacement than waves with the highest velocity peaks, but I wouldn't worry too much about that happening except when you are looking at a local event. And in your case, if the period was also 13 sec like mine, Peak displacement = 2.6mm/s * 13s / 2Pi = 5.37mm peak or nearly 1.1 cm p-p. Brett At 06:28 PM 8/3/2009 -0600, you wrote: >Hi Brett, How do I set up WinSDR or Winquake to view as movement? ( I >recorded 2.6 mm of movement on the vertical channel) > >Thanks, Ted > > >----- Original Message ----- From: "Brett Nordgren" >To: >Sent: Monday, August 03, 2009 5:56 PM >Subject: Re: Large Response Coming in Now at 18:00 UTC > > >>Bob >> >>Now that I corrected the y-scale the plot from our vertical >>http://bnordgren.org/seismo/090803.175000.bhz-pl.psn.gif shows roughly >>3mm/s peak, which agrees pretty well with the values (assuming you meant >>mm/s) that you were seeing. This is from near LA which is at about 6.5 >>deg. It's interesting that if you assume the predominant frequency was >>1/13 seconds, that should imply that the vertical ground motion at Dave's >>vault was about 6.2mm peak or 1.24 cm p-p. That's a lot of motion! >> >>For laughs, I uploaded the output from the high gain channel >>http://bnordgren.org/seismo/090803.175000.bhz-ph.psn.gif which clips at >>300um/s and indeed it clipped. However, the low gain channel should be >>able to handle up to 1.5cm/sec peak. >> >>Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response Coming in Now at 18:00 UTC From: Brett Nordgren brett3nt@............. Date: Mon, 03 Aug 2009 21:08:39 -0400 Ted, I see that you can indeed do some WinQuake magic to get your answer much easier. Just use View > Integrate Data, and if you were recording velocity, it will give you a plot of displacement. For my recording it showed a peak displacement of about 6.1mm. Brett At 06:28 PM 8/3/2009 -0600, you wrote: >Hi Brett, How do I set up WinSDR or Winquake to view as movement? ( I >recorded 2.6 mm of movement on the vertical channel) > >Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Gulf of California quakes From: Thomas Dick dickthomas01@............. Date: Tue, 04 Aug 2009 09:05:50 -0500 I have two questions 1. what kind of faulting was it that did not produce a tsunami in an enclosed area like this 2. why didn't national news networks cover it __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Gulf of California quakes From: Bob Hancock icarus@......... Date: Tue, 4 Aug 2009 07:15:13 -0700 The answer to your first question is the focal mechanism of the event was a strike slip or lateral movement. See link: http://neic.usgs.gov/neis/eq_depot/2009/eq_090803_jwbh/neic_jwbh_cmt.html Tsunamis are more easily generated by vertical movement. The answer to your second question depends upon the networks you listen to. I saw extensive coverage of the multiple events including interviews of people from south of the border on Fox News. Bob Hancock On Aug 4, 2009, at 7:05 AM, Thomas Dick wrote: > I have two questions > 1. what kind of faulting was it that did not produce a tsunami in an > enclosed area like this > 2. why didn't national news networks cover it > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body > of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Gulf of California quakes From: Thomas Dick dickthomas01@............. Date: Tue, 04 Aug 2009 12:57:56 -0500 Tnx Bob Hancock > The answer to your first question is the focal mechanism of the event > was a strike slip or lateral movement. See link: Ok, I lacked knowledge in that area and then this fault was a branch/extension of the San Andres fault. > > Tsunamis are more easily generated by vertical movement. > > The answer to your second question depends upon the networks you > listen to. I saw extensive coverage of the multiple events including > interviews of people from south of the border on Fox News. > NBC didn't cover it at all. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: M 6.9 Gulf of Mexico Event From: Bob Hancock icarus@......... Date: Tue, 4 Aug 2009 16:06:16 -0700 The University of Arizona, Geosciences Division has a page devoted to this event. See link below: http://www.geo.arizona.edu/gsat/GulfCalifornia.htm Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Gulf of California quakes From: "K.-Benoit Evans" kevans@............ Date: Tue, 04 Aug 2009 19:43:11 -0400 On 2009-08-04, at 10:05, Thomas Dick wrote: > 2. why didn't national news networks cover it It got fleeting mention on FOX and CNN. However, our modern news media =20= dismissed it because "there were no reports of damage or injuries". No =20= death, no gore, no buildings falling down ergo no detailed coverage. Regards, Beno=EEt Evans __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: "Geoffrey" gmvoeth@........... Date: Wed, 5 Aug 2009 08:02:15 -0700 Hello Bob & Brett ; If you were looking only for first arrival times Id think High gain is the way to go. You must see the noise because the emerging signal can sometimes be a part of the noise. Many signals i get from this area seems to attenuate the P wave in a way it arises slowly out of the grass and in such a case where exactly is the first arrival time. Most not likely the time you actually see. If somehow you could use a FFT to see the first arrival time I think that may be the way to go but since you need many samples to use the fft it may not be possible to see the exact arrival. Does anyone know of processing routines that will pull a signal out of the grass other than a FFT routine ?? ----- Original Message ----- From: "Brett Nordgren" To: Sent: Monday, August 03, 2009 5:02 PM Subject: Re: Large Response. Corrected URL Bob For laughs, I uploaded the output from the high gain channel http://bnordgren.org/seismo/090803.175000.bhz-ph.psn.gif Brett At 11:28 AM 8/3/2009 -0700, you wrote: >There are two events, the first one if listed as M 5.8, the second event >is M 6.9. I recorded 2.6 mm of movement on the vertical channel, 3.8 mm >on the North channel, and 2.0 mm of movement on East channel. My station >is only 3.43 degrees (381.14 km) from the event. > >Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: Bob Hancock icarus@......... Date: Wed, 5 Aug 2009 19:59:03 -0700 Hi Geoff - I cannot speak about high gain, but to understand the signals you received, you also need to understand focal mechanism. The focal mechanism of the M 6.9 Gulf of Mexico event was a strike slip. See links below: http://neic.usgs.gov/neis/eq_depot/2009/eq_090803_jwbh/neic_jwbh_cmt.html http://neic.usgs.gov/neis/eq_depot/2009/eq_090803_jwbh/neic_jwbh_hrv.html Following is a very simplistic explanation of focal mechanism for a strike slip event. NOTE - As the focal mechanism changes to other than strike slip, the following will not apply. The radiation pattern of a strike slip event is 4 lobed with two lobs compressional and two lobs dilation. When you look at the sphere, you see it is divided into 4 quadrants, and it is like you are looking at the bottom inside of the beech ball that had been cut in half. The dividers are called fault planes. When rocks break under pressure, they tend to break on a 45 degree line from the compression, although in reality it could easily vary between 30 & 60 degrees depending upon several factors. The problem is determining which fault plane the rocks actually broke on as the physics of the fracture will be the same on either fault plane. When focal mechanisms are listed, they list two fault planes labeled NP1, the most likely occurrence, and NP2, the alternate occurrence. The two colored quadrants (most often red or black) represent the compressional quadrants when the initial movement of the P wave on the vertical channel is up. The non-colored or open quadrants are the dilation quadrants where the initial movement of the P wave on the vertical channel will move down. Understanding the focal mechanism will allow you to understand where the peak amplitudes and null points of the four basic waves, P, S, Love, & Rayleigh will occur. The peak of the P wave and Rayleigh waves whether compression or dilation will be midway between the fault planes, and they become weakest at the fault planes. The peak amplitude on the S waves and Love waves whether compression or dilation occur on the fault planes and they are weakest in the middle between the fault planes. Now, back to our M 6.9 event. Both of our stations are very close to this event and we were both in the dilation quadrant for the P wave on the vertical channel. I looked at both my data and that from IU/TUC and they were the same. On each station, the P waves were lost in the trailing coda from the preceding M 5.8 event of similar location. This has nothing to do with filtering, but everything to do with the closeness of the second event following the first event, and the lack of time for the earth to settle down after the first event. I hope this helps. Bob Hancock On Aug 5, 2009, at 8:02 AM, Geoffrey wrote: > Hello Bob & Brett ; > If you were looking only for first arrival times > Id think High gain is the way to go. > You must see the noise because the emerging > signal can sometimes be a part of the noise. > Many signals i get from this area seems > to attenuate the P wave in a way it arises > slowly out of the grass and in such a case > where exactly is the first arrival time. > Most not likely the time you actually see. > If somehow you could use a FFT to see > the first arrival time I think that may be > the way to go but since you need many > samples to use the fft it may not be possible > to see the exact arrival. > Does anyone know of processing routines > that will pull a signal out of the grass other > than a FFT routine ?? > > i __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: Brett Nordgren brett3nt@............. Date: Wed, 05 Aug 2009 23:20:12 -0400 Hi Geoffry, To see the P arrival I normally just turn up the WinQuake Y scale. Since the basic sensitivity is a better than 10nm/count, you can expand it quite a lot. See: http://bnordgren.org/seismo/090803.175000.bhz-ph2.psn.gif You can pretty well see where the Pn starts around 17:57:00 which is made clearer with a 0.2sec low-pass filter. Looking at the arrival time tables, it would seem that you have the 5.8 with a predicted Pn arrival at 17:57:00 getting its later phases mixed with the 6.9, which has a predicted Pn arrival at 18:01:33. They are going to be pretty hard to untangle. Regards, Brett At 08:02 AM 8/5/2009 -0700, you wrote: >Hello Bob & Brett ; >If you were looking only for first arrival times >Id think High gain is the way to go. >You must see the noise because the emerging >signal can sometimes be a part of the noise. >Many signals i get from this area seems >to attenuate the P wave in a way it arises >slowly out of the grass and in such a case >where exactly is the first arrival time. >Most not likely the time you actually see. >If somehow you could use a FFT to see >the first arrival time I think that may be >the way to go but since you need many >samples to use the fft it may not be possible >to see the exact arrival. >Does anyone know of processing routines >that will pull a signal out of the grass other >than a FFT routine ?? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: "Geoffrey" gmvoeth@........... Date: Thu, 6 Aug 2009 04:10:16 -0700 HOWDY PSN; You Guys are really getting heavy into the theory which goes far above and beyond What I am doing. But thanks anyway. Has any of you seen a small event with an origin time of between 03:05:40 TO 03:05:53 2009AUG06 UTC I do not see it reported. Im just trying to get a magnitude for this event. I need to get better Magnitudes from WQ since changing my Amplifier. I would use this to set the numbers for regional magnitudes. Thanks; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Response. Corrected URL From: Bob Hancock icarus@......... Date: Thu, 6 Aug 2009 17:41:49 -0700 IU/TUC recorded a VERY WEAK signal that peaks at 0307:38. You cannot distinguish the body waves, only the surface waves. The rest is lost in the background. Bob Hancock On Aug 6, 2009, at 4:10 AM, Geoffrey wrote: > HOWDY PSN; > > You Guys are really getting heavy into > the theory which goes far above and > beyond What I am doing. > But thanks anyway. > > Has any of you seen a small event with > an origin time of between > 03:05:40 TO > 03:05:53 > 2009AUG06 UTC > > I do not see it reported. > > Im just trying to get a magnitude for this event. > I need to get better Magnitudes from WQ since > changing my Amplifier. I would use this > to set the numbers for regional magnitudes. > > > Thanks; > geoff > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Has Any one tried this kind of pendulum ? From: "Geoffrey" gmvoeth@........... Date: Fri, 7 Aug 2009 12:54:27 -0700 Hello PSN: I was just looking at this page http://njsas.org/projects/tidal_forces/01/baker/index.html It seems to show a horizontal pendulum at the top. What I was wondering is if you could build a pendulum with a rod and mass maybe 18 inches below the pivot or more then extend the rod one inch ABOVE the fulcrum of crossed rods bearing then attach maybe a circular super magnet then on either side of that magnet attached to the pendulum attach two opposing super magnets at some adjustable distance either side to act as a magnetic spring. If you do this you may be able to totally eliminate the mechanical spring and the ability to adjust the opposing magnets will also adjust its period or whatever. It will not be linear but may allow for greater dynamic range due to its non linear magnetic characteristics ?? I do not have the ability to try this out but maybe one or more of you already have??? Thoughts ??? Regards; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Need pwr. supp. schematic for Amp/filter board From: George Bush ke6pxp@....... Date: Sat, 08 Aug 2009 13:53:15 -0700 Hi Larry- The new system is working beautifully. I appreciate your equipment, software, and help! Now I want to correct a frustration with the Seismic Amplifier/filter board part of the system. I have absolutely no complalints with the board. For a while I was running both the new serial and the old comp board A/D systems in parallel at the end of the 100' cable between my garage and my shop plus another 50' of cable to the house and a drum galvonometer, and your amp board drove all of this perfectly! But during the many years the system has been operating, the UPS on the system in the garage has failed and been replaced 3 times. I want to go to a battery/trickle charger setup and get rid of the UPS dc to ac converter. I noticed that the specs on your latest amp/filter board updated 1/19/08 listed that dc or ac power could be used. My Ver I, rev 1.5 board only works with an ac transformer. I would like to look at your current power supply and see if I could convert my board to dc input also. I would appreciate it if you could send the URL of the power supply schematic for the current Seismic Amplifier/filter Board you sell. Thanks- George George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Sorry! From: George Bush ke6pxp@....... Date: Sat, 08 Aug 2009 14:27:14 -0700 Hi- Sorry to mis-send a query to Larry Cochrane to the whole list! But maybe it is all right to send him a public thanks for all he has done for us! Thanks- George George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Has Any one tried this kind of pendulum ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 08 Aug 2009 23:16:27 +0000 Hi I am thinking of building one at school this winter. As I am going to study electronics this winter, this might be a good project to do. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-07 at 12:54 -0700, Geoffrey wrote: > Hello PSN: >=20 > I was just looking at this page > http://njsas.org/projects/tidal_forces/01/baker/index.html >=20 > It seems to show a horizontal pendulum at the top. >=20 > What I was wondering is if you could build a > pendulum with a rod and mass maybe 18 inches > below the pivot or more then extend the rod one inch > ABOVE the fulcrum of crossed rods bearing > then attach maybe a circular super magnet > then on either side of that magnet attached to > the pendulum attach two opposing super magnets > at some adjustable distance either side to > act as a magnetic spring. If you do this > you may be able to totally eliminate the mechanical > spring and the ability to adjust the opposing magnets > will also adjust its period or whatever. > It will not be linear but may allow for greater > dynamic range due to its non linear > magnetic characteristics ?? >=20 > I do not have the ability to try this out > but maybe one or more of you already have??? >=20 > Thoughts ??? >=20 > Regards; > geoff > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with=20 > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: USGS NetQuakes: Overview From: "Jim ODonnell" geophysics@.......... Date: Mon, 10 Aug 2009 14:13:25 GMT Hi All- My colleagues in the USGS have come up with a good idea to get more sei= smic data fast. = Note they are using accelerometers. Many possibilities here! <<<<<<< Jim NetQuakes: Overview var map; var geoXml; addEvent(window, "load", fun= ction() { onLoad(); });function onLoad() { if (GBrowserIsCompatible())= { geoXml =3D new GGeoXml("http://earthquake.usgs.gov/eqcenter/wavef= orms/netq/nocal.kml"); map =3D new GMap2(document.getElementById("ma= p")); map.addControl(new GLargeMapControl()); map.setCenter(new = GLatLng(37.6, -122.25), 8); map.addControl(new GMapTypeControl()); = map.addMapType(G_PHYSICAL_MAP); var controls =3D new GHierarchicalM= apTypeControl(); map.addOverlay(geoXml); }}The USGS is trying to a= chieve a denser and more uniform seismograph spacing in selected urban a= reas to provide better measurements of ground motion during earthquakes.= These measurements improve our ability to make rapid post-earthquake as= sessments of expected damage and contribute to the continuing developmen= t of engineering standards for construction. = To do this, we have developed a new type of digital seismograph that com= municates its data to the USGS via the Internet. These instruments conne= ct to a local network using WiFi and use existing Broadband connections = to transmit data after an earthquake. These seismographs have been desig= ned to be installed in private homes, businesses, public buildings and s= chools where there is an existing Broadband connection to the Internet. = = We are looking for people who are willing to host these "NetQuakes" seis= mographs. The NetQuakes seismographs access the Internet via a wireless = router connected to your existing Broadband Internet connection. The sei= smograph transmits data only after earthquakes above about magnitude 3 a= nd will otherwise not consume any significant bandwidth. A website is no= w available to view the most recent triggered activity at each seismogra= ph. You can see where NetQuakes seismographs are currently installed in = the Bay Area. = http://earthquake.usgs.gov/eqcenter/waveforms/netq/ Jim O'Donnell- Geophysical Consultant/Contractor Geotechnical/Geothermal/Oil & Gas/Mining Applications Seismic Surveys- Surface Waves, Refraction, & Reflection Ground Penetrating Radar, Resistivity, Magnetic, & VLF-EM Surveys Geophysics@.......... 702.293.5664 702.281.9081 cell = Boulder City, NV
Hi All-
My colleagues in the USGS have come up with a good = idea to get more seismic data fast.
Note they are using acceler= ometers.
Many possibilities here! <<<<<<<&= nbsp;    Jim

NetQuakes: Overview

The USGS is trying to achieve a denser and more uniform seismograph spac= ing in selected urban areas to provide better measurements of ground mot= ion during earthquakes. These measurements improve our ability to make r= apid post-earthquake assessments of expected damage and contribute to th= e continuing development of engineering standards for construction.
=
To do this, we have developed a new type of digital seismograph that= communicates its data to the USGS via the Internet. These instruments c= onnect to a local network using WiFi and use existing Broadband connecti= ons to transmit data after an earthquake. These seismographs have been d= esigned to be installed in private homes, businesses, public buildings a= nd schools where there is an existing Broadband connection to the Intern= et.

We are looking for people who are willing to host these "Net= Quakes" seismographs. The NetQuakes seismographs access the Internet via= a wireless router connected to your existing Broadband Internet connect= ion. The seismograph transmits data only after earthquakes above about m= agnitude 3 and will otherwise not consume any significant bandwidth. A w= ebsite is now available to view the most recent triggered activity at each seismogr= aph. You can see where NetQuakes seismographs are currently= installed in the Bay Area.

http://earthquake.usgs.gov/eqcenter/waveform= s/netq/

Jim O'Donnell- Geophysical Consultant/Contractor
Geote= chnical/Geothermal/Oil & Gas/Mining Applications
Seismic Surveys-= Surface Waves, Refraction, & Reflection
Ground Penetrating Radar= , Resistivity, Magnetic, & VLF-EM Surveys
Geophysics@.......... &= nbsp;702.293.5664 702.281.9081 cell
Boulder City, = NV
Subject: Re: USGS NetQuakes: Overview From: ChrisAtUpw@....... Date: Mon, 10 Aug 2009 21:30:00 EDT In a message dated 10/08/2009, geophysics@.......... writes: Hi All- My colleagues in the USGS have come up with a good idea to get more seismic data fast. Note they are using accelerometers. Many possibilities here! <<<<<<< Jim NetQuakes: Overview Hi Jim, There would be considerably more possibilities if your references were accessable!!!! I get a message that the Session at emailmyname has expired and inviting me to register at this unknown site, which I suspect is unsafe. Can you sort your references out / provide alternatives, please? Regards, Chris Chapman

In a message dated 10/08/2009, geophysics@.......... writes:

Hi All-
My colleagues in the USGS have come up with a good idea to= get=20 more seismic data fast.
Note they are using accelerometers.
= Many=20 possibilities here! <<<<<<<   = =20 Jim

NetQuakes: Overview

Hi Jim,

    There would be considerably more possibilitie= s if=20 your references were accessable!!!!

    I get a message that the Session at emailmyna= me has=20 expired and inviting me to register at this unknown site, which I sus= pect=20 is unsafe.

    Can you sort your references out / provide=20 alternatives, please?

    Regards,

    Chris Chapman
Subject: Re: USGS NetQuakes: Overview From: "Jim ODonnell" geophysics@.......... Date: Tue, 11 Aug 2009 02:30:40 GMT Hi Chris- See if these work<<<<<<<<<<<< Jim NetQuakes: Overview http://earthquake.usgs.gov/eqcenter/waveforms/netq/ = Choose a station from the list and choose a date and click 'view' http://earthquake.usgs.gov/eqcenter/waveforms/netq/trigs/ = NetQuakes: Installed (Map) http://earthquake.usgs.gov/eqcenter/waveforms/netq/installed.php = = Jim O'Donnell- Geophysical Consultant/Contractor Geotechnical/Geothermal/Oil & Gas/Mining Applications Seismic Surveys- Surface Waves, Refraction, & Reflection Ground Penetrating Radar, Resistivity, Magnetic, & VLF-EM Surveys Geophysics@.......... 702.293.5664 702.281.9081 cell = Boulder City, NV ---------- Original Message ---------- From: ChrisAtUpw@....... To: psn-l@.............. Subject: Re: USGS NetQuakes: Overview Date: Mon, 10 Aug 2009 21:30:00 EDT In a message dated 10/08/2009, geophysics@.......... writes:Hi All- My colleagues in the USGS have come up with a good idea to get more seis= mic data fast. = Note they are using accelerometers. Many possibilities here! <<<<<<< Jim NetQuakes: OverviewHi Jim, There would be considerably more possibil= ities if your references were accessable!!!! I get a message that th= e Session at emailmyname has expired and inviting me to register at this= unknown site, which I suspect is unsafe. Can you sort your reference= s out / provide alternatives, please? Regards, Chris Chapman Hi Chris-
See if these work<<<<<<<<<= <<<      Jim

NetQuakes:= Overview

http://earthquake.usgs.gov/eqcenter/waveforms/netq/

Choose a station from the list and choose a date and click 'view'
=
http://earthquake.usgs.gov/eqcenter/waveforms/netq/trig= s/

NetQuakes:= Installed (Map)

http://earthquake.usgs.gov/eqcenter/waveforms/ne= tq/installed.php

Jim O'Donnell= - Geophysical Consultant/Contractor
Geotechnical/Geothermal/Oil &= Gas/Mining Applications
Seismic Surveys- Surface Waves, Refraction, = & Reflection
Ground Penetrating Radar, Resistivity, Magnetic, &am= p; VLF-EM Surveys
Geophysics@.......... 702.293.5664 702.= 281.9081 cell
Boulder City, NV

---------- Ori= ginal Message ----------
From: ChrisAtUpw@.......
To: psn-l@webtro= nics.com
Subject: Re: USGS NetQuakes: Overview
Date: Mon, 10 Aug 2= 009 21:30:00 EDT

In a message dated 10/08/2009, geophysics@.......... writes:

Hi All-
My colleagues in the USGS have come up with a good idea to= get more seismic data fast.
Note they are using accelerometers= ..
Many possibilities here! <<<<<<< &n= bsp;   Jim

NetQuakes: Overview

Hi Jim,

    There would be considerably more possibilit= ies if your references were accessable!!!!

    I get a message that the Session at emailmy= name has expired and inviting me to register at this unknown site, which= I suspect is unsafe.

    Can you sort your references out / provide = alternatives, please?

    Regards,

    Chris Chapman
Subject: Real time traces From: Brett Nordgren brett3nt@............. Date: Thu, 13 Aug 2009 15:47:26 -0400 Hello All, We just put up a Web page which displays some near real time outputs from two of our experimental vertical feedback seismographs. There are displays showing three different combinations of sensitivity and low-pass filtering, which highlight different types of ground motion. http://bnordgren.org/seismo/gif_images.htm Currently these are updated every 30 minutes, though in the future we may be able to reduce the update interval. As these are experimental instruments, it may happen that they will occasionally be off line as we make improvements. We sometime see short data dropouts, possibly related to the convoluted data path we use to distribute the gif's. Data starts in Dave Nelson's seismo vault in California, arrives via the Internet at my WinSDR client in New Jersey where the gif files get generated. They then are uploaded to my Web site, hosted in Pittsburgh... and so on. I am still working to figure out the cause of the data drops. Suggestions welcomed. Enjoy. Regards, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: meredith lamb paleoartifact@......... Date: Thu, 13 Aug 2009 23:09:10 -0600 Brett, Boy....you guys sure know how to torture people...with the 2 mysterious unseen undefined experimental instruments. How about a web photo's "sneak peek" of the verticals? :>) Meredith Lamb On Thu, Aug 13, 2009 at 1:47 PM, Brett Nordgren wrote: > Hello All, > > We just put up a Web page which displays some near real time outputs from > two of our experimental vertical feedback seismographs. There are displays > showing three different combinations of sensitivity and low-pass filtering, > which highlight different types of ground motion. > > http://bnordgren.org/seismo/gif_images.htm > > Currently these are updated every 30 minutes, though in the future we may > be able to reduce the update interval. As these are experimental > instruments, it may happen that they will occasionally be off line as we > make improvements. > > We sometime see short data dropouts, possibly related to the convoluted > data path we use to distribute the gif's. Data starts in Dave Nelson's > seismo vault in California, arrives via the Internet at my WinSDR client in > New Jersey where the gif files get generated. They then are uploaded to my > Web site, hosted in Pittsburgh... and so on. I am still working to figure > out the cause of the data drops. Suggestions welcomed. > > Enjoy. > > Regards, > Brett > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
Brett,

=A0

Boy....you guys sure know how to=A0torture people...with the 2 mysteri= ous unseen undefined experimental instruments.

How about a web photo's "sneak peek" of the verticals?= =A0 :>)

=A0

Meredith Lamb

On Thu, Aug 13, 2009 at 1:47 PM, Brett Nordgren = <brett3nt@bn= ordgren.org> wrote:

Hello All,

We just put up= a Web page which displays some near real time outputs from two of our expe= rimental vertical feedback seismographs. =A0There are displays showing thre= e different combinations of sensitivity and low-pass filtering, which highl= ight different types of ground motion.

http://bnordgren.org/seismo/gif_images.htm

Currently these are= updated every 30 minutes, though in the future we may be able to reduce th= e update interval. As these are experimental instruments, it may happen tha= t they will occasionally be off line as we make improvements.

We sometime see short data dropouts, possibly related to the convoluted= data path we use to distribute the gif's. =A0Data starts in Dave Nelso= n's seismo vault in California, arrives via the Internet at my WinSDR c= lient in New Jersey where the gif files get generated. =A0They then are upl= oaded to my Web site, hosted in Pittsburgh... and so on. =A0I am still work= ing to figure out the cause of the data drops. =A0Suggestions welcomed.

Enjoy.

Regards,
Brett

____________________________= ______________________________

Public Seismic Network Mailing List (= PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the bod= y of the message (first line only): unsubscribe
See h= ttp://www.seismicnet.com/maillist.html for more information.

Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Fri, 14 Aug 2009 12:51:29 -0400 Meredith, We certainly don't want to be accused of torture, though we'll gladly plead guilty to some discreet teasing. For a little more tease, see http://bnordgren.org/seismo/FBVert01.zip a photo and a couple of sketches. The photo shows a slightly earlier configuration, but is basically what Dave is running now. We want to go slowly in regards to encouraging folks to start trying to make something like this until we feel we're able to do our part to help with any problems. Building one of these would definitely not be a good first project, though I think we are coming to the point where we can provide some more detail if there is any particular interest. Regards, Brett At 11:09 PM 8/13/2009 -0600, you wrote: >Brett, > >Boy....you guys sure know how to torture people...with the 2 mysterious >unseen undefined experimental instruments. >How about a web photo's "sneak peek" of the verticals? :>) > >Meredith Lamb > >On Thu, Aug 13, 2009 at 1:47 PM, Brett Nordgren wrote: >>Hello All, >> >>We just put up a Web page which displays some near real time outputs from >>two of our experimental vertical feedback seismographs. There are >>displays showing three different combinations of sensitivity and low-pass >>filtering, which highlight different types of ground motion. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: "Kay Wyatt" kwyatt@............. Date: Fri, 14 Aug 2009 10:03:31 -0700 Brett, I am curious about the installation enclosure for your seismometer. It looks like a granite slab surrounded by a plastic enclosure. Is this located in a basement or is it outside. How do you insure it is waterproof? What is the granite slab setting on? What type of plastic enclosure are you using. Thanks so much, Kay Wyatt ----- Original Message ----- From: "Brett Nordgren" To: Sent: Friday, August 14, 2009 9:51 AM Subject: Re: Real time traces > Meredith, > > We certainly don't want to be accused of torture, though we'll gladly > plead guilty to some discreet teasing. > > For a little more tease, see http://bnordgren.org/seismo/FBVert01.zip > a photo and a couple of sketches. The photo shows a slightly earlier > configuration, but is basically what Dave is running now. > > We want to go slowly in regards to encouraging folks to start trying to > make something like this until we feel we're able to do our part to help > with any problems. Building one of these would definitely not be a good > first project, though I think we are coming to the point where we can > provide some more detail if there is any particular interest. > > Regards, > Brett > > > > At 11:09 PM 8/13/2009 -0600, you wrote: >>Brett, >> >>Boy....you guys sure know how to torture people...with the 2 mysterious >>unseen undefined experimental instruments. >>How about a web photo's "sneak peek" of the verticals? :>) >> >>Meredith Lamb >> >>On Thu, Aug 13, 2009 at 1:47 PM, Brett Nordgren wrote: >>>Hello All, >>> >>>We just put up a Web page which displays some near real time outputs from >>>two of our experimental vertical feedback seismographs. There are >>>displays showing three different combinations of sensitivity and low-pass >>>filtering, which highlight different types of ground motion. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: meredith lamb paleoartifact@......... Date: Fri, 14 Aug 2009 11:51:37 -0600 Hi Brett and Dave, I'am "assuming" the "2" instruments is really the one ~ same ~ vertical (?), with either mechanical changes and/or feedback changes? As usual (for me), the main spring (phosphor bronze) and the two pivot flexure assemblys (with presumably 6 total pieces) are of quite some curiosity. Of what material, size/s, thickness are you guys using? Some of the flexures shown almost look like cut thin flat spring steel from the photo. Take care, Meredith On Fri, Aug 14, 2009 at 10:51 AM, Brett Nordgren wrote: > Meredith, > > We certainly don't want to be accused of torture, though we'll gladly plead > guilty to some discreet teasing. > > For a little more tease, see http://bnordgren.org/seismo/FBVert01.zip > a photo and a couple of sketches. The photo shows a slightly earlier > configuration, but is basically what Dave is running now. > > We want to go slowly in regards to encouraging folks to start trying to > make something like this until we feel we're able to do our part to help > with any problems. Building one of these would definitely not be a good > first project, though I think we are coming to the point where we can > provide some more detail if there is any particular interest. > > Regards, > Brett > > > >
Hi Brett and Dave,

=A0

I'am "assuming" the "2" instruments is really = the one ~ same ~ vertical (?), with either mechanical changes and/or

feedback changes?

=A0

As usual (for me), the main spring (phosphor bronze) and the two pivot= flexure assemblys=A0(with presumably 6 total pieces) are of=A0quite some c= uriosity.=A0 Of what material, size/s, thickness are you guys using?=A0 Som= e of the flexures shown almost look

like cut thin flat spring=A0steel from the photo.

=A0

Take care, Meredith=A0

On Fri, Aug 14, 2009 at 10:51 AM, Brett Nordgren= <brett3nt@b= nordgren.org> wrote:

Meredith,

We certainly do= n't want to be accused of torture, though we'll gladly plead guilty= to some discreet teasing.

For a little more tease, see =A0 http://bnordgren.org/seismo/FBVert01.zip =A0 =A0a photo and a couple of sketches. =A0The photo shows a slightly e= arlier configuration, but is basically what Dave is running now.

We want to go slowly in regards to encouraging folks to start trying to= make something like this until we feel we're able to do our part to he= lp with any problems. =A0Building one of these would definitely not be a go= od first project, though I think we are coming to the point where we can pr= ovide some more detail if there is any particular interest.=20

Regards,
Brett

Subject: Re: Real time traces/ Vault design From: "Dave Nelson" davefnelson@....... Date: Fri, 14 Aug 2009 18:00:59 -0000 I think Its time for me to join the conversation. The installation for my broadband seismometers is a concrete pier set on the local bedrock . The pier is poured with the traditional 50/50 sand cement mixture with 2 or 3 inches of clearance between the pier and the sides of the hole . The pier is topped with a granite slab bonded to the pier with a layer of thinset mortar. The pier is enclosed by a commercial plastic building with an interior door separating the building into two compartments creating an insulated and sealed inner "vault" for the instruments. No part of the plastic building is in contact with the pier. Power is brought into the building from an external UPS and multiple internet connections are also internal to the enclosure. The computers are remotely located connected to the A/D with an Edgeport USD to serial converter and USB over Cat 5 extenders. I have two of Larry's A/D's in the vault. All instruments and in the vault are powered by a battery with a floating charger. In spite of being in the Los Angeles urban area the noise below 5 Hz is quite low. The Palos Verdes Peninsula is a large monolith which is essentially a part of the coastal mountain range. The Los Angeles "basin" is alluvium which seems to isolate urban noise from the rock I sit on. I am 200 M above sea level and surrounded on three sides by ocean (the land mass is a peninsula). The closest beach is about 4 km. Currently I am running a modified 3 axis Guralp borehole instrument of early (1987) vintage along with two of my fluid based FMES horizontals which respond from 4 Hz to 20 seconds and are seismic background noise limited. I have two vertical force balance instruments as Brett is describing in the vault in pressure sealed cases. The enclosure for these instruments and the method for employing them for is extremely important to reduce/eliminate atmospheric buoyancy noise without introducing flexure in the instrument base plate. The Force Balance Verticals are still somewhat developmental but work extremely well. I have a new version of the circuit board with minor revisions about to be installed and some ideas for simplifying the mechanical design which will be tried in the next month or two. Dave Nelson (Los Angeles) ----- Original Message ----- From: "Kay Wyatt" To: Sent: Friday, August 14, 2009 17:03 Subject: Re: Real time traces > Brett, > > I am curious about the installation enclosure for your seismometer. It > looks like a granite slab surrounded by a plastic enclosure. Is this > located in a basement or is it outside. How do you insure it is > waterproof? What is the granite slab setting on? What type of plastic > enclosure are you using. > > Thanks so much, > Kay Wyatt > > > ----- Original Message ----- > From: "Brett Nordgren" > To: > Sent: Friday, August 14, 2009 9:51 AM > Subject: Re: Real time traces > > >> Meredith, >> >> We certainly don't want to be accused of torture, though we'll gladly >> plead guilty to some discreet teasing. >> >> For a little more tease, see http://bnordgren.org/seismo/FBVert01.zip a >> photo and a couple of sketches. The photo shows a slightly earlier >> configuration, but is basically what Dave is running now. >> >> We want to go slowly in regards to encouraging folks to start trying to >> make something like this until we feel we're able to do our part to help >> with any problems. Building one of these would definitely not be a good >> first project, though I think we are coming to the point where we can >> provide some more detail if there is any particular interest. >> >> Regards, >> Brett >> >> >> >> At 11:09 PM 8/13/2009 -0600, you wrote: >>>Brett, >>> >>>Boy....you guys sure know how to torture people...with the 2 mysterious >>>unseen undefined experimental instruments. >>>How about a web photo's "sneak peek" of the verticals? :>) >>> >>>Meredith Lamb >>> >>>On Thu, Aug 13, 2009 at 1:47 PM, Brett Nordgren wrote: >>>>Hello All, >>>> >>>>We just put up a Web page which displays some near real time outputs >>>>from two of our experimental vertical feedback seismographs. There are >>>>displays showing three different combinations of sensitivity and >>>>low-pass filtering, which highlight different types of ground motion. >> >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: "Dave Nelson" davefnelson@....... Date: Fri, 14 Aug 2009 18:12:22 -0000 Hi Meredith, The spring is 17-7 stainless condition C heat treated to condition = CH900. Thickness is 12 mils. The pivots are 2 mil stainless single axis = .. Pivot length is only about 12 mils. They are held tension by the C = spring. A two axis pivot is not necessary. Dave=20 ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Friday, August 14, 2009 17:51 Subject: Re: Real time traces Hi Brett and Dave, I'am "assuming" the "2" instruments is really the one ~ same ~ = vertical (?), with either mechanical changes and/or feedback changes? As usual (for me), the main spring (phosphor bronze) and the two pivot = flexure assemblys (with presumably 6 total pieces) are of quite some = curiosity. Of what material, size/s, thickness are you guys using? = Some of the flexures shown almost look like cut thin flat spring steel from the photo. Take care, Meredith=20 On Fri, Aug 14, 2009 at 10:51 AM, Brett Nordgren = wrote: Meredith, We certainly don't want to be accused of torture, though we'll = gladly plead guilty to some discreet teasing. For a little more tease, see = http://bnordgren.org/seismo/FBVert01.zip a photo and a couple of = sketches. The photo shows a slightly earlier configuration, but is = basically what Dave is running now. We want to go slowly in regards to encouraging folks to start trying = to make something like this until we feel we're able to do our part to = help with any problems. Building one of these would definitely not be a = good first project, though I think we are coming to the point where we = can provide some more detail if there is any particular interest.=20 Regards, Brett
Hi Meredith,

The spring is 17-7 stainless = condition C heat=20 treated to condition CH900. Thickness is 12 mils. The pivots are 2 = mil=20 stainless single axis . Pivot length is only about 12 mils. = They are=20 held tension by the C spring. A two axis pivot is not=20 necessary.

Dave

----- Original Message -----
From:=20 meredith lamb
To: psn-l@..............

Sent: Friday, August 14, 2009 = 17:51

Subject: Re: Real time = traces

Hi Brett and Dave,

I'am "assuming" the "2" instruments is really the one ~ same ~ = vertical=20 (?), with either mechanical changes and/or

feedback changes?

As usual (for me), the main spring (phosphor bronze) and the two = pivot=20 flexure assemblys (with presumably 6 total pieces) are = of quite some=20 curiosity. Of what material, size/s, thickness are you guys = using? =20 Some of the flexures shown almost look

like cut thin flat spring steel from the photo.

Take care, Meredith

On Fri, Aug 14, 2009 at 10:51 AM, Brett = Nordgren <brett3nt@.............>=20 wrote:
Meredith,

We certainly don't want to be = accused of=20 torture, though we'll gladly plead guilty to some discreet=20 teasing.

For a little more tease, see http://bnordgren.org/seismo/FBVert01.zip = a=20 photo and a couple of sketches. The photo shows a slightly = earlier=20 configuration, but is basically what Dave is running now.

We = want to=20 go slowly in regards to encouraging folks to start trying to make = something=20 like this until we feel we're able to do our part to help with any = problems.=20 Building one of these would definitely not be a good first = project,=20 though I think we are coming to the point where we can provide some = more=20 detail if there is any particular interest.=20

Regards,
Brett

Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Fri, 14 Aug 2009 14:12:44 -0400 Kay, Here are some pictures of Dave's vault to add to his description. http://bnordgren.org/seismo/vault01.zip I'm assuming he doesn't mind my sharing them--it is quite a beautiful job. Regards, Brett At 10:03 AM 8/14/2009 -0700, you wrote: >Brett, > >I am curious about the installation enclosure for your seismometer. It >looks like a granite slab surrounded by a plastic enclosure. Is this >located in a basement or is it outside. How do you insure it is >waterproof? What is the granite slab setting on? What type of plastic >enclosure are you using. > >Thanks so much, >Kay Wyatt __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: "Dave Nelson" davefnelson@....... Date: Fri, 14 Aug 2009 18:32:00 -0000 Hi Meredith, Just one other point . The free period can be adjusted easily by = changing the spring length from fairly short periods to infinite period = and over to the negative period region where the spring mass system is = unstable. The free period is usually set to about 3 seconds. The free period in a = closed loop system is relatively unimportant as long as it is somewhere = in the 1 second and longer region. The Guralp sensors have a free period = of only 1/2 second and a 360 second long period response. Dave=20
Hi Meredith,

Just one other point . The free period = can be=20 adjusted easily by changing the spring length from fairly short = periods to=20 infinite period and over to the negative period region where the = spring=20 mass system is unstable.

The free period is usually set to = about 3=20 seconds. The free period in a closed loop system is relatively = unimportant=20 as long as it is somewhere in the 1 second and longer region. The Guralp = sensors=20 have a free period of only 1/2 second and a 360 second long period=20 response.

Dave

Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Fri, 14 Aug 2009 15:10:28 -0400 Meredith, The 2 instruments are two copies of almost exactly the same design. There are a few minor evolutionary changes, but the only significant difference is in the design of the pressure containers surrounding them. It is much fun (for me anyway) to watch them draw out virtually identical traces of the microseisms, right along with the Guralp. One thing we have learned in working on this design is that the pivot flexures have almost no effect. All my earlier efforts at making zero-moment designs just aren't necessary. Any slight restoring moment that the flexures create is completely cancelled when the period is adjusted as Dave described, by tweaking the spring length. And the angle that they flex through during normal operation is essentially zero because of the feedback. For Kay: I just checked on the Garden Shed/Vault that I believe Dave had used: Rubbermaid RHP3673 Approximately a 6' x 6' base. In looking for the model number I ran across this somewhat amusing clip of a couple assembling a similar shed. http://blog.rubbermaid.com/home/2008/06/heres-how-to-bu.html Regards, Brett At 11:51 AM 8/14/2009 -0600, you wrote: >Hi Brett and Dave, > >I'am "assuming" the "2" instruments is really the one ~ same ~ vertical >(?), with either mechanical changes and/or >feedback changes? > >As usual (for me), the main spring (phosphor bronze) and the two pivot >flexure assemblys (with presumably 6 total pieces) are of quite some >curiosity. Of what material, size/s, thickness are you guys using? Some >of the flexures shown almost look >like cut thin flat spring steel from the photo. > >Take care, Meredith __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Latest Quakes as seen from GVA From: "Geoffrey" gmvoeth@........... Date: Sat, 15 Aug 2009 09:34:32 -0700 Hello PSN; As I am not up to your level of expertise I shall post the latest quakes I get always to my personal web space as the following images to download. 9:17 AM 8/15/2009 http://gmvoeth.home.mchsi.com/GVA_LATEST.gif http://gmvoeth.home.mchsi.com/GVA_LATEST.bmp http://gmvoeth.home.mchsi.com/GVA_LATEST.jpg These will be updated only sporadically since if errors are found in timing or missed by my automated recorder they will not be posted. I do not keep a history since the USGS never requested I do so. To save bandwidth; Please choose only one file format they are all B/W images originally produced by Larry's Program Winquake3x. This very first one I am doing this way seems to be Mexico according to the USGS. You can check from time to time and As I verify the ones I catch they will be posted here with the very same filenames. I am truly an layman amateur most interested in the instrumentation above all else. If you are unable to download via this address, I will be happy to send an image as an attachment if you make a personal request to me at gmvoeth@........... I do not really understand the PSN postings of images so will not use that method yet. Best regards to all within PSN; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: meredith lamb paleoartifact@......... Date: Sat, 15 Aug 2009 18:18:57 -0600 Hi Dave, Thanks for the info. Was wondering about the main spring width...its hard to judge from the photo; and where you got such and the ~ cost? The photo spring looks to be a original coil strip or a good home shear. I understand (via the web) its magnetic; but apparently it works fine regardless of the boom end coil/magnet actuator feedback influence. Midway atop your vertical mechanism there appears to be a screw adjustable mass balance or centering counterweight. I presume....that the main spring period is adjusted via the back clamp alone. The very small size of the vertical is rather startling for the ~ giant ~ mechanisms we're used too seeing on PSN. I can't really tell if their is more added mass to the boom via the photo's besides the ~ frame, coil, capacitance plate. What did you use for the coil? Homebrew wound or otherwise a commerical coil? What is the magnet, ring ceramic or neodymium? Take care, Meredith Lamb On Fri, Aug 14, 2009 at 12:12 PM, Dave Nelson wrote: > Hi Meredith, > > The spring is 17-7 stainless condition C heat treated to condition CH900. > Thickness is 12 mils. The pivots are 2 mil stainless single axis . Pivot > length is only about 12 mils. They are held tension by the C spring. A two > axis pivot is not necessary. > > > Dave > > > > > >
Hi Dave,

=A0

Thanks for the info.=A0 Was wondering about the main spring width...it= s hard to judge from the photo; and where you got such

and the ~ cost?=A0 The photo spring looks to be a original coil strip = or a good home shear.=A0 I understand (via the web) its

magnetic; but apparently it works fine regardless of the boom end coil= /magnet actuator feedback influence.=A0

=A0

Midway atop your vertical mechanism there appears to be a screw adjust= able mass balance or centering=A0counterweight.

=A0

I presume....that the main spring period is adjusted via the back clam= p alone.=A0

=A0

The very small size=A0of the vertical is rather=A0startling for the ~ = giant ~ mechanisms we're used too seeing on PSN.

I can't really tell if their is more added mass to the boom via th= e=A0photo's besides the ~ frame, coil,=A0capacitance plate.

=A0

What did you use for the coil?=A0 Homebrew wound or otherwise a commer= ical coil?

=A0

What is the magnet, ring ceramic or neodymium?

=A0

Take care, Meredith Lamb

=A0

=A0

On Fri, Aug 14, 2009 at 12:12 PM, Dave Nelson <davefnelson@.......> wrote:

Hi Meredith,

=A0

The spring is 17-7=A0 stainless condit= ion C heat treated to condition CH900. Thickness is 12 mils. =A0The pivots = are 2 mil stainless single axis=A0.=A0 Pivot length is only about 12 mils. = They are held=A0 tension by the=A0C spring. A two axis pivot is not necessa= ry.

=A0

=A0

Dave

=A0

=A0

=A0
Subject: Re: Real time traces From: "Dave Nelson" davefnelson@....... Date: Sun, 16 Aug 2009 01:43:20 -0000 Hi Meredith. The spring is cut to width on my personal shear and heat treated in the = home oven in the automatic cleaning mode. The heat treat significantly = increases the yield strength. The temperature is just right as measured = with a thermocouple. The width for the instrument pictured is 16 mm and = thickness is 12 mils. (Sorry for the mixed units -- our European = friends will think we can't make up our minds )=20 I have a large quantity of the raw material for the springs -- enough = for any conceivable quantity of instruments. I am working on the = repeatability in the shearing process. Right now I can do +- ~.15mm. As you suggest the period is a function of the spring length and = adjusted at the clamp. It sometimes takes a few tries but the process is = quite easy. The period and rough centering are done with the center = capacitor plate PC board removed to allow for a motion over large angle = for convenience. The final mass centering is done by adjusting the = moveable mass either by eye or using the LED's on the electronics board = with the loop open. The integrator is designed to hold center over a = wide temperature range so reentering is probably not necessary under all = but the most severe climatic temperature changes. We estimate +- 30C = but that is not fully confirmed. Actuator is homebrew based in a Neodymium magnet purchased on Ebay. The = coil is wound on a modified PAC plumbing part (1 1/4 Schedule 40 plug = from Lowes). It takes a few minutes of lathe work to make it . The coil = is 770 turns of # 32 for about 50 ohms and 15 N/A. I fabricate the = magnet assembly also but it does take some minor MIG tack welds. The = materials are available from Online Metals.=20 There is another small mass at he coil attach point of ~ 10 grams. =20 The overall size of the basic mechanism exclusive of the case is 4.5 x = 9.5 inches. I have a new (untried) design which will be 4.5 x 5 inches = in a somewhat different configuration which may allow for buoyancy = compensation. The new design is also easier to build or at least that = is the goal.=20 Regards, Dave=20 ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Sunday, August 16, 2009 00:18 Subject: Re: Real time traces Hi Dave, Thanks for the info. Was wondering about the main spring width...its = hard to judge from the photo; and where you got such and the ~ cost? The photo spring looks to be a original coil strip or = a good home shear. I understand (via the web) its magnetic; but apparently it works fine regardless of the boom end = coil/magnet actuator feedback influence.=20 Midway atop your vertical mechanism there appears to be a screw = adjustable mass balance or centering counterweight. I presume....that the main spring period is adjusted via the back = clamp alone. =20 The very small size of the vertical is rather startling for the ~ = giant ~ mechanisms we're used too seeing on PSN. I can't really tell if their is more added mass to the boom via the = photo's besides the ~ frame, coil, capacitance plate. What did you use for the coil? Homebrew wound or otherwise a = commerical coil? What is the magnet, ring ceramic or neodymium? Take care, Meredith Lamb On Fri, Aug 14, 2009 at 12:12 PM, Dave Nelson = wrote: Hi Meredith, The spring is 17-7 stainless condition C heat treated to condition = CH900. Thickness is 12 mils. The pivots are 2 mil stainless single axis = .. Pivot length is only about 12 mils. They are held tension by the C = spring. A two axis pivot is not necessary. Dave=20
Hi Meredith.

The spring is cut to width on my = personal shear and=20 heat treated in the home oven in the automatic cleaning mode. The = heat=20 treat significantly increases the yield strength. The temperature is = just right=20 as measured with a thermocouple. The width for the instrument pictured = is 16 mm=20 and thickness is 12 mils. (Sorry for the mixed units -- our = European=20 friends will think we can't make up our minds )

I have a large quantity of the = raw material=20 for the springs -- enough for any conceivable quantity of instruments. I = am=20 working on the repeatability in the shearing process. Right now I = can do=20 +- ~.15mm.

As you suggest the period is a = function of=20 the spring length and adjusted at the clamp. It sometimes takes a few = tries but=20 the process is quite easy. The period and rough centering are done = with=20 the center capacitor plate PC board removed to allow for a = motion=20 over large angle for convenience. The final mass centering is done by = adjusting=20 the moveable mass either by eye or using the LED's on the = electronics=20 board with the loop open. The integrator is designed to hold center over = a wide=20 temperature range so reentering is probably not necessary under all but = the most=20 severe climatic temperature changes. We estimate +- 30C but that = is not=20 fully confirmed.

Actuator is homebrew based in a = Neodymium magnet=20 purchased on Ebay. The coil is wound on a modified PAC plumbing = part (1=20 1/4 Schedule 40 plug from Lowes).  It takes a few minutes of = lathe=20 work to make it . The coil is 770 turns of # 32 for about 50 = ohms and=20 15 N/A. I fabricate the magnet assembly also but it does take some = minor =20 MIG tack welds. The materials are available  from Online = Metals.=20

There is another small mass at he coil = attach point=20 of ~ 10 grams.

The overall size of the basic mechanism = exclusive=20 of the case is 4.5 x 9.5 inches. I have a new (untried) design which = will be 4.5=20 x 5 inches in a somewhat different configuration which may allow = for =20 buoyancy compensation. The new design is also easier to build or = at least=20 that is the goal.

Regards, Dave

----- Original Message -----
From:=20 meredith lamb
To: psn-l@..............

Sent: Sunday, August 16, 2009 = 00:18

Subject: Re: Real time = traces

Hi Dave,

Thanks for the info. Was wondering about the main spring=20 width...its hard to judge from the photo; and where you got such

and the ~ cost? The photo spring looks to be a original = coil strip=20 or a good home shear. I understand (via the web) its

magnetic; but apparently it works fine regardless of the boom end = coil/magnet actuator feedback influence.

Midway atop your vertical mechanism there appears to be a screw=20 adjustable mass balance or centering counterweight.

I presume....that the main spring period is adjusted via the back = clamp=20 alone.

The very small size of the vertical is rather startling = for the=20 ~ giant ~ mechanisms we're used too seeing on PSN.

I can't really tell if their is more added mass to the boom via=20 the photo's besides the ~ frame, coil, capacitance = plate.

What did you use for the coil? Homebrew wound or otherwise = a=20 commerical coil?

What is the magnet, ring ceramic or neodymium?

Take care, Meredith Lamb

On Fri, Aug 14, 2009 at 12:12 PM, Dave Nelson = <davefnelson@.......> wrote:

Hi Meredith,

The spring is 17-7 stainless = condition C=20 heat treated to condition CH900. Thickness is 12 mils. The = pivots are=20 2 mil stainless single axis . Pivot length is only about = 12 mils.=20 They are held tension by the C spring. A two axis pivot = is not=20 necessary.

Dave

=

Subject: Re: Real time traces From: meredith lamb paleoartifact@......... Date: Sat, 15 Aug 2009 23:18:45 -0600 Hi Dave, I'am totally impressed with all that has been done.....its been rather amazing to hear of the extent to which you guys have pursued to derive the materials for the parts of the seismometer; and of course the patience and determination to bring such about! It will certainly be most interesting to hear about the even smaller (potential) vertical seismometer in time. That kind of time delayed anticipation torture (ha) is good for us. Take care, Meredith On Sat, Aug 15, 2009 at 7:43 PM, Dave Nelson wrote: > Hi Meredith. > > The spring is cut to width on my personal shear and heat treated in the > home oven in the automatic cleaning mode. The heat treat significantly > increases the yield strength. The temperature is just right as measured with > a thermocouple. The width for the instrument pictured is 16 mm and thickness > is 12 mils. (Sorry for the mixed units -- our European friends will think > we can't make up our minds ) > > I have a large quantity of the raw material for the springs -- enough for > any conceivable quantity of instruments. I am working on the repeatability > in the shearing process. Right now I can do +- ~.15mm. > > As you suggest the period is a function of the spring length and adjusted > at the clamp. It sometimes takes a few tries but the process is quite easy. > The period and rough centering are done with the center capacitor plate PC > board removed to allow for a motion over large angle for convenience. The > final mass centering is done by adjusting the moveable mass either by eye > or using the LED's on the electronics board with the loop open. The > integrator is designed to hold center over a wide temperature range so > reentering is probably not necessary under all but the most severe climatic > temperature changes. We estimate +- 30C but that is not fully confirmed. > > > Actuator is homebrew based in a Neodymium magnet purchased on Ebay. The > coil is wound on a modified PAC plumbing part (1 1/4 Schedule 40 plug from > Lowes). It takes a few minutes of lathe work to make it . The coil is 770 > turns of # 32 for about 50 ohms and 15 N/A. I fabricate the magnet assembly > also but it does take some minor MIG tack welds. The materials are > available from Online Metals. > > There is another small mass at he coil attach point of ~ 10 grams. > > The overall size of the basic mechanism exclusive of the case is 4.5 x 9.5 > inches. I have a new (untried) design which will be 4.5 x 5 inches in a > somewhat different configuration which may allow for buoyancy compensation. > The new design is also easier to build or at least that is the goal. > > > Regards, Dave > > > > >
Hi Dave,

=A0

I'am totally impressed with all that has been done.....its been ra= ther amazing to hear of the extent to which

you guys have pursued to derive the materials for the parts of the sei= smometer; and of course the patience

and determination to=A0bring such about!

=A0

It will certainly be most interesting to hear about the even smaller (= potential) vertical seismometer in time.

That kind of time delayed anticipation torture (ha) is good for us.
=A0

Take care, Meredith

=A0

=A0

On Sat, Aug 15, 2009 at 7:43 PM, Dave Nelson <davefnelson@.......> wrote:

Hi Meredith.

=A0

The spring is cut to width on my perso= nal shear and heat treated in the home oven in the automatic cleaning mode.= =A0 The heat treat significantly increases the yield strength. The temperat= ure is just right as measured with a thermocouple. The width for the instru= ment pictured is 16 mm and thickness is 12 mils.=A0 (Sorry for the mixed un= its -- our European friends will think we can't=A0 make up our minds )= =A0

=A0

=A0I have a large quantity of the raw = material for the springs -- enough for any conceivable quantity of instrume= nts. I am working on the =A0repeatability in the shearing process. Right no= w I can do +- ~.15mm.

=A0

As you suggest the period is=A0 a func= tion of the spring length and adjusted at the clamp. It sometimes takes a f= ew tries but the process is quite easy.=A0 The period and rough centering a= re done with the=A0 center capacitor plate PC board =A0removed to allow for= a motion over large angle for convenience. The final mass centering is don= e by adjusting the moveable mass =A0either by eye or using the LED's on= the electronics board with the loop open. The integrator is designed to ho= ld center over a wide temperature range so reentering is probably not neces= sary under all but the most severe climatic temperature changes. We estimat= e +- 30C=A0 but that is not fully confirmed.

=A0

=A0

Actuator is homebrew based in a Neodym= ium magnet purchased on Ebay. The coil is wound on a modified PAC plumbing = part=A0 (1 1/4 Schedule 40 plug from Lowes).=A0=A0It takes a few minutes of= lathe work to make it=A0. The coil is 770 turns=A0of # 32 for about 50 ohm= s and 15 N/A. I fabricate the magnet assembly also but it does take some mi= nor=A0 MIG tack welds. The materials are available=A0=A0from Online Metals.=

=A0

There is another small mass at he coil= attach point of=A0~ 10 grams.=A0

=A0

The overall size of the basic mechanis= m exclusive of the case is 4.5 x 9.5 inches. I have a new (untried) design = which will be 4.5 x 5 inches in a somewhat different configuration which ma= y=A0allow for=A0 buoyancy compensation. =A0The new design is also easier to= build or at least that is the goal.

=A0

=A0

Regards, Dave

=A0

=A0

=A0

=A0
Subject: Re: Real time traces From: Barry Lotz barry_lotz@............. Date: Sun, 16 Aug 2009 04:18:19 -0700 (PDT) Dave I'm interested in finding out more and impressed also. I reduced the size o= f the STM style vertical 12" but like your design. Didn't you try a hacksaw= blade(s)=A0 before? I don't remember the thickness but would the taping bl= ade material STM mentioned work? I'm not sure about my heat treating abilit= ies (proper annealing etc). I have read Bretts excellent documentation in t= he past. Regards Barry --- On Sat, 8/15/09, Dave Nelson wrote: From: Dave Nelson Subject: Re: Real time traces To: psn-l@.............. Date: Saturday, August 15, 2009, 6:43 PM =0A=0A =0A =0A=0AHi Meredith.=0A=A0=0AThe spring is cut to width on my pers= onal shear and =0Aheat treated in the home oven in the automatic cleaning m= ode.=A0 The heat =0Atreat significantly increases the yield strength. The t= emperature is just right =0Aas measured with a thermocouple. The width for = the instrument pictured is 16 mm =0Aand thickness is 12 mils.=A0 (Sorry for= the mixed units -- our European =0Afriends will think we can't=A0 make up = our minds )=A0=0A=A0=0A=A0I have a large quantity of the raw material =0Afo= r the springs -- enough for any conceivable quantity of instruments. I am = =0Aworking on the =A0repeatability in the shearing process. Right now I can= do =0A+- ~.15mm.=0A=A0=0AAs you suggest the period is=A0 a function of =0A= the spring length and adjusted at the clamp. It sometimes takes a few tries= but =0Athe process is quite easy.=A0 The period and rough centering are do= ne with =0Athe=A0 center capacitor plate PC board =A0removed to allow for a= motion =0Aover large angle for convenience. The final mass centering is do= ne by adjusting =0Athe moveable mass =A0either by eye or using the LED's on= the electronics =0Aboard with the loop open. The integrator is designed to= hold center over a wide =0Atemperature range so reentering is probably not= necessary under all but the most =0Asevere climatic temperature changes. W= e estimate +- 30C=A0 but that is not =0Afully confirmed.=0A=A0=0A=A0=0AActu= ator is homebrew based in a Neodymium magnet =0Apurchased on Ebay. The coil= is wound on a modified PAC plumbing part=A0 (1 =0A1/4 Schedule 40 plug fro= m Lowes).=A0=A0It takes a few minutes of lathe =0Awork to make it=A0. The c= oil is 770 turns=A0of # 32 for about 50 ohms and =0A15 N/A. I fabricate the= magnet assembly also but it does take some minor=A0 =0AMIG tack welds. The= materials are available=A0=A0from Online Metals. =0A=0A=A0=0AThere is anot= her small mass at he coil attach point =0Aof=A0~ 10 grams.=A0 =0A=A0=0AThe = overall size of the basic mechanism exclusive =0Aof the case is 4.5 x 9.5 i= nches. I have a new (untried) design which will be 4.5 =0Ax 5 inches in a = somewhat different configuration which may=A0allow for=A0 =0Abuoyancy compe= nsation. =A0The new design is also easier to build or at least =0Athat is t= he goal. =0A=A0=0A=A0=0ARegards, Dave =0A=A0=0A=A0=0A=A0=0A=A0=0A----- Orig= inal Message ----- =0A=0A From: =0A meredith lamb =0A To: psn-l@webtroni= cs.com =0A Sent: Sunday, August 16, 2009 00:18=0A Subject: Re: Real time = traces=0A =20 =0A Hi Dave,=0A =A0=0A Thanks for the info.=A0 Was wondering about the m= ain spring =0A width...its hard to judge from the photo; and where you got= such=0A and the ~ cost?=A0 The photo spring looks to be a original coil s= trip =0A or a good home shear.=A0 I understand (via the web) its=0A magne= tic; but apparently it works fine regardless of the boom end =0A coil/magn= et actuator feedback influence.=A0=0A =A0=0A Midway atop your vertical me= chanism there appears to be a screw =0A adjustable mass balance or centeri= ng=A0counterweight.=0A =A0=0A I presume....that the main spring period is= adjusted via the back clamp =0A alone.=A0 =0A =A0=0A The very small siz= e=A0of the vertical is rather=A0startling for the =0A ~ giant ~ mechanisms= we're used too seeing on PSN.=0A I can't really tell if their is more add= ed mass to the boom via =0A the=A0photo's besides the ~ frame, coil,=A0cap= acitance plate.=0A =A0=0A What did you use for the coil?=A0 Homebrew woun= d or otherwise a =0A commerical coil?=0A =A0=0A What is the magnet, ring= ceramic or neodymium?=0A =A0=0A Take care, Meredith Lamb=0A =A0=0A =A0= =0A On Fri, Aug 14, 2009 at 12:12 PM, Dave Nelson wr= ote: =0A =0A =0A Hi Meredith,=0A =A0=0A The spring is 17-7=A0 stain= less condition C =0A heat treated to condition CH900. Thickness is 12 mi= ls. =A0The pivots are =0A 2 mil stainless single axis=A0.=A0 Pivot lengt= h is only about 12 mils. =0A They are held=A0 tension by the=A0C spring.= A two axis pivot is not =0A necessary.=0A =A0=0A =A0=0A Dave = =0A =A0=0A =A0=0A =0A =A0
Dave
I'm interested in finding out more an= d impressed also. I reduced the size of the STM style vertical 12" but like= your design. Didn't you try a hacksaw blade(s) before? I don't remem= ber the thickness but would the taping blade material STM mentioned work? I= 'm not sure about my heat treating abilities (proper annealing etc). I have= read Bretts excellent documentation in the past.
Regards
Barry

--- On Sat, 8/15/09, Dave Nelson <davefnelson@.......> wrote:

From: Dave Nelson <davefnel= son@.......>
Subject: Re: Real time traces
To: psn-l@.............. m
Date: Saturday, August 15, 2009, 6:43 PM

=0A=0A =0A =0A=0A
Hi M= eredith.
=0A
<= /div>=0A
The spring is cut to width on = my personal shear and =0Aheat treated in the home oven in the automatic cle= aning mode. The heat =0Atreat significantly increases the yield stren= gth. The temperature is just right =0Aas measured with a thermocouple. The = width for the instrument pictured is 16 mm =0Aand thickness is 12 mils.&nbs= p; (Sorry for the mixed units -- our European =0Afriends will think we can'= t make up our minds )
=0A

=0A
= ;I have a large quantity of the raw material =0Afor the springs -- enough f= or any conceivable quantity of instruments. I am =0Aworking on the re= peatability in the shearing process. Right now I can do =0A+- ~.15mm.
=0A

=0A
<= font size=3D"2" face=3D"Arial">As you suggest the period is a functio= n of =0Athe spring length and adjusted at the clamp. It sometimes takes a f= ew tries but =0Athe process is quite easy. The period and rough cente= ring are done with =0Athe center capacitor plate PC board remov= ed to allow for a motion =0Aover large angle for convenience. The final mas= s centering is done by adjusting =0Athe moveable mass either by eye o= r using the LED's on the electronics =0Aboard with the loop open. The integ= rator is designed to hold center over a wide =0Atemperature range so reente= ring is probably not necessary under all but the most =0Asevere climatic te= mperature changes. We estimate +- 30C but that is not =0Afully confir= med.
=0A
=0A

=0A
Actuator is homebrew based in a Neodymium magnet = =0Apurchased on Ebay. The coil is wound on a modified PAC plumbing part&nbs= p; (1 =0A1/4 Schedule 40 plug from Lowes).  It takes a few minute= s of lathe =0Awork to make it . The coil is 770 turns of # 32 for= about 50 ohms and =0A15 N/A. I fabricate the magnet assembly also but it d= oes take some minor =0AMIG tack welds. The materials are available&nb= sp; from Online Metals. =0A
=0A

=0A
There= is another small mass at he coil attach point =0Aof ~ 10 grams. =
=0A

= =0A
The overall size of the basic mecha= nism exclusive =0Aof the case is 4.5 x 9.5 inches. I have a new (untried) d= esign which will be 4.5 =0Ax 5 inches in a somewhat different configuratio= n which may allow for =0Abuoyancy compensation. The new de= sign is also easier to build or at least =0Athat is the goal.
= =0A

=0A

=0A
Regards, Dave
=0A
=
=0A
=0A

=0A

=0A
----- Original Messag= e -----
=0A
=0A
From: =0A meredith lamb =
=0A
To:= psn-l@..............
=0A
Sent: Sunday, August 16, 2009 00:18
=0A =
Subject: Re: R= eal time traces
=0A

=0A
Hi Dave,
=0A
=
=0A
Thanks for the info. Was wondering about the ma= in spring =0A width...its hard to judge from the photo; and where you got = such
=0A
and the ~ cost? The photo spring looks to be a or= iginal coil strip =0A or a good home shear. I understand (via the we= b) its
=0A
magnetic; but apparently it works fine regardless of = the boom end =0A coil/magnet actuator feedback influence.
=0A =

=0A
Midway atop your vertical mechanism there appear= s to be a screw =0A adjustable mass balance or centering counterweigh= t.
=0A

=0A
I presume....that the main spring p= eriod is adjusted via the back clamp =0A alone.
=0A
&nbs= p;
=0A
The very small size of the vertical is rather s= tartling for the =0A ~ giant ~ mechanisms we're used too seeing on PSN.=0A
I can't really tell if their is more added mass to the boom vi= a =0A the photo's besides the ~ frame, coil, capacitance plate.<= /div>=0A

=0A
What did you use for the coil? H= omebrew wound or otherwise a =0A commerical coil?
=0A
=0A
What is the magnet, ring ceramic or neodymium?
=0A
=
=0A
Take care, Meredith Lamb
=0A

= =0A

=0A
On Fri, Aug 14, 2009 = at 12:12 PM, Dave Nelson <davefnelson@.......> wrote:
=0A =0A
=0A Hi Meredith,
=0A

=0A
The spring is 17-7 stainless condition C =0A heat= treated to condition CH900. Thickness is 12 mils. The pivots are =0A= 2 mil stainless single axis . Pivot length is only about 12 = mils. =0A They are held tension by the C spring. A two axis p= ivot is not =0A necessary.
=0A

=0A

=0A
Dave
=0A

=0A
<= /div>=0A
=0A

<= /div>
Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Sun, 16 Aug 2009 09:32:32 -0400 Barry, Thanks for the kind words. I'll try to keep more coming. Regarding spring thickness: There is a direct relationship between the stress level in the spring, its thickness and how sharply it is bent as defined by its radius of bending. Approximately: max stress = Elastic modulus * thickness / (2 * min bend radius) So for a given max stress we get thickness = 2 * max stress * min bend radius / Elastic modulus This obviously works for any units, so long the units of thickness and radius are the same, and stress and Elastic modulus are also. Putting some numbers to that: desired max stress 72,000 psi min bend radius = 2.5" Elastic Modulus from a table of metal properties = 3E7 psi (or a little less) So thickness = 2 * 72,000 * 2.5 / 3E7 = 0.012" Bending the spring more sharply requires thinner material to stay below the same max stress. For a spring bent to this radius, hacksaw blades and taping blades are quite a bit too thick. One issue is that you want to keep the stress level much lower than the yield stress of the spring material to stay far away from any issues like creep or hysteresis losses. Clock makers seem to be designing their springs to stay under 40% of yield. When hardened , the 17-7 stainless appears to achieve a yield strength above 280,000 psi, so we're in great shape, only 25% of yield. Even without hardening, the 17-7 is not so bad (198,000 psi), but from Dave's reports the hardening process for this material is not all that difficult.....bake it at 900 +/- 10 deg F for 1 hour, then let it cool. If you want all the gory details about the material, and more, see. http://bnordgren.org/seismo/17-7_Stainless.zip You can watch the seismo make wiggles on Larry's page http://psn.quake.net/currentseismicity.html Thanks, Larry Big quake this morning. Regards, Brett At 04:18 AM 8/16/2009 -0700, you wrote: >Dave >I'm interested in finding out more and impressed also. I reduced the size >of the STM style vertical 12" but like your design. Didn't you try a >hacksaw blade(s) before? I don't remember the thickness but would the >taping blade material STM mentioned work? I'm not sure about my heat >treating abilities (proper annealing etc). I have read Bretts excellent >documentation in the past. >Regards >Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: Barry Lotz barry_lotz@............. Date: Sun, 16 Aug 2009 15:12:07 -0700 (PDT) Brett I'm an engineer but more familiar with small deflection theory. I'll go bac= k to my college notes :) Thanks for the info on the stainless. Barry --- On Sun, 8/16/09, Brett Nordgren wrote: From: Brett Nordgren Subject: Re: Real time traces To: psn-l@.............. Date: Sunday, August 16, 2009, 6:32 AM Barry, Thanks for the kind words.=A0 I'll try to keep more coming. Regarding spring thickness:=A0 There is a direct relationship between the s= tress level in the spring, its thickness and how sharply it is bent as defi= ned by its radius of bending. Approximately:=A0 max stress =3D Elastic modulus * thickness / (2 * min ben= d radius) So for a given max stress we get=A0=A0=A0thickness =3D 2 * max stress * min= bend radius / Elastic modulus This obviously works for any units, so long the units of thickness and radi= us are the same, and stress and Elastic modulus are also. Putting some numbers to that: desired max stress 72,000 psi min bend radius =3D 2.5" Elastic Modulus from a table of metal properties =3D 3E7 psi (or a little l= ess) So=A0=A0=A0thickness =3D 2 * 72,000 * 2.5 / 3E7 =3D 0.012" Bending the spring more sharply requires thinner material to stay below the= same max stress. For a spring bent to this radius, hacksaw blades and taping blades are quit= e a bit too thick. One issue is that you want to keep the stress level much lower than the yie= ld stress of the spring material to stay far away from any issues like cree= p or hysteresis losses.=A0 Clock makers seem to be designing their springs = to stay under 40% of yield. When hardened , the 17-7 stainless appears to achieve a yield strength abov= e 280,000 psi, so we're in great shape, only 25% of yield.=A0 Even without = hardening, the 17-7 is not so bad (198,000 psi), but from Dave's reports th= e hardening process for this material is not all that difficult.....bake it= at 900 +/- 10 deg F for 1 hour, then let it cool. If you want all the gory details about the material, and more, see.=A0 =A0 = http://bnordgren.org/seismo/17-7_Stainless.zip You can watch the seismo make wiggles on Larry's page=A0 http://psn.quake.n= et/currentseismicity.html=A0 =A0 Thanks, Larry Big quake this morning. Regards, Brett At 04:18 AM 8/16/2009 -0700, you wrote: > Dave > I'm interested in finding out more and impressed also. I reduced the size= of the STM style vertical 12" but like your design. Didn't you try a hacks= aw blade(s)=A0 before? I don't remember the thickness but would the taping = blade material STM mentioned work? I'm not sure about my heat treating abil= ities (proper annealing etc). I have read Bretts excellent documentation in= the past. > Regards > Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Brett
I'm an engineer but more familiar wi= th small deflection theory. I'll go back to my college notes :) Thanks for = the info on the stainless.
Barry

--- On Sun, 8/16/09, = Brett Nordgren <brett3nt@.............> wrote:

From: Brett Nordgren <brett3nt@.............>Subject: Re: Real time traces
To: psn-l@..............
Date: Sunday,= August 16, 2009, 6:32 AM

Barry,

Tha= nks for the kind words. I'll try to keep more coming.

Regardin= g spring thickness: There is a direct relationship between the stress= level in the spring, its thickness and how sharply it is bent as defined b= y its radius of bending.

Approximately: max stress =3D Elastic= modulus * thickness / (2 * min bend radius)

So for a given max stress we ge= t   thickness =3D 2 * max stress * min bend radius / Elastic= modulus

This obviously works for any units, so long the units of th= ickness and radius are the same, and stress and Elastic modulus are also.
Putting some numbers to that:
desired max stress 72,000 psi
min= bend radius =3D 2.5"
Elastic Modulus from a table of metal properties = =3D 3E7 psi (or a little less)

So   thickness =3D 2 *= 72,000 * 2.5 / 3E7 =3D 0.012"

Bending the spring more sharply requi= res thinner material to stay below the same max stress.

For a spring= bent to this radius, hacksaw blades and taping blades are quite a bit too = thick.

One issue is that you want to keep the stress level much lowe= r than the yield stress of the spring material to stay far away from any is= sues like creep or hysteresis losses. Clock makers seem to be designi= ng their springs to stay under 40% of yield.

When hardened , the 17-7 = stainless appears to achieve a yield strength above 280,000 psi, so we're i= n great shape, only 25% of yield. Even without hardening, the 17-7 is= not so bad (198,000 psi), but from Dave's reports the hardening process fo= r this material is not all that difficult.....bake it at 900 +/- 10 deg F f= or 1 hour, then let it cool.

If you want all the gory details about = the material, and more, see. http://bnordgren.org/seismo/17-= 7_Stainless.zip

You can watch the seismo make wiggles on Larry's= page http://psn.quake.net/currentseismicity.html Th= anks, Larry
Big quake this morning.

Regards,
Brett

At 0= 4:18 AM 8/16/2009 -0700, you wrote:
> Dave
> I'm interested in finding out more and impressed also. I reduced the size of the STM style v= ertical 12" but like your design. Didn't you try a hacksaw blade(s) b= efore? I don't remember the thickness but would the taping blade material S= TM mentioned work? I'm not sure about my heat treating abilities (proper an= nealing etc). I have read Bretts excellent documentation in the past.
&g= t; Regards
> Barry

_______________________________________= ___________________

Public Seismic Network Mailing List (PSN-L)
<= br>To leave this list email PSN-L-REQUEST@SE= ISMICNET.COM with the body of the message (first line only): unsubscrib= e
See http://www.seismicnet.com/maillist.html for more information.
Subject: New mag 8> earthquake coming near Sumatra ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 16 Aug 2009 22:52:10 +0000 Hi all. I have been watching the earthquake swarm near Sumatra and Andman Islands (KEP. MENTAWAI REGION, INDONESIA) that is currently going on. Over the past few hours I have been seeing partterns that worries me. There are clues building up that a new major earthquake might strike in the area soon, when exacly I am not sure at this time. But it might happen soon, given the current earthquake swarm development. A magnitude 8> earthquake has been prediected by sicetists in earthquake research, according to news from 2008. News about new large (megathrust?) earthquake in the Sumatra area. http://www.sciencedaily.com/releases/2008/12/081203131042.htm I fear that this might happen soon. The clues that I am getting do come from the current earthquake swarm in the area, but it was started by a Mw6.9 earthquake today, and there is a good chance that the Mw7.6 earthquake the other day has something to do with this swarm also due to near breaking point of the fault lines over there. At current, the best time frame that I can give somewhere around 3 to 5 weeks time at the earliest. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: WinSDR question From: Brett Nordgren brett3nt@............. Date: Mon, 17 Aug 2009 14:55:19 -0400 Hi All, I have been trying to provide calibration data for our 24-hour displays, by going to Settings > Channel Control > DC Offset, putting in a number, then watching how far the trace moves up/down. Knowing the instrument sensitivity per count, I can translate that into velocity units per line. I had been assuming that the number I was entering for the DC Offset is always representing counts, but now I am not so sure. Does anyone know how that works? BTW I am getting frequent short data dropouts in the output display. I have tracked that down to the possibility that I don't have enough RAM (512MB) and am planning to add some more to see if that makes things better. Thanks, Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: ChrisAtUpw@....... Date: Mon, 17 Aug 2009 21:01:48 EDT In a message dated 17/08/2009, brett3nt@............. writes: BTW I am getting frequent short data dropouts in the output display. I have tracked that down to the possibility that I don't have enough RAM (512MB) and am planning to add some more to see if that makes things better. Hi Brett, This is most likely to be due to timing problems or to data rate settings near critical values. You can also get it if the processor tries to switch RAM. Check the free RAM and check that the data rates are within specification. The AS-1s have these problems due to a PZT timing ''crystal'' on the processor board in place of quartz. Regards, Chris

In a message dated 17/08/2009, brett3nt@............. writes:
BTW I am=20 getting frequent short data dropouts in the output display. I
= have=20 tracked that down to the possibility that I don't have enough RAM
(5= 12MB)=20 and am planning to add some more to see if that makes things=20 better.

Hi Brett,

    This is most likely to be due to timing probl= ems or=20 to data rate settings near critical values. You can also get it if the pro= cessor=20 tries to switch RAM. Check the free RAM and check that the data rates are= within=20 specification. The AS-1s have these problems due to a PZT timing ''crystal= '' on=20 the processor board in place of quartz.

    Regards,

    Chris
Subject: Re: WinSDR question From: Brett Nordgren brett3nt@............. Date: Mon, 17 Aug 2009 21:23:22 -0400 Hi Chris, At 09:01 PM 8/17/2009 -0400, you wrote: >In a message dated 17/08/2009, brett3nt@............. writes: >>BTW I am getting frequent short data dropouts in the output display. I >>have tracked that down to the possibility that I don't have enough RAM >>(512MB) and am planning to add some more to see if that makes things better. >Hi Brett, > > This is most likely to be due to timing problems or to data rate > settings near critical values. You can also get it if the processor tries > to switch RAM. Check the free RAM and check that the data rates are > within specification. The AS-1s have these problems due to a PZT timing > ''crystal'' on the processor board in place of quartz. I didn't mention that I am running as a Client to Dave's machine. He usually doesn't have the dropouts at his end. Also in a 24x1hour display, the currently drawing line doesn't have a problem, but when it gets to the end of the line and the screen redraws to make room for the next one, the line which was just completed now has had a ~1 minute 'dropout' inserted near its beginning. The reason the gaps are not at the beginning of the hour in the gif's is because my screen display is rarely synchronized to the start of the hour. I was just considering how much data it takes to display 24 hours at 200 samples per second. A bunch. Thanks for the suggestions, Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: Larry Cochrane lcochrane@.............. Date: Tue, 18 Aug 2009 19:41:40 -0700 Brett, > Hi All, > > I have been trying to provide calibration data for our 24-hour displays, by > going to Settings > Channel Control > DC Offset, putting in a number, then > watching how far the trace moves up/down. Knowing the instrument > sensitivity per count, I can translate that into velocity units per > line. I had been assuming that the number I was entering for the DC Offset > is always representing counts, but now I am not so sure. > > Does anyone know how that works? Looking at the code the offset is applied to the A/D count and then divided by a number to get the trace to show up in the right Y location depending on the Y Scale. Here's the code: yLoc = lineOffset + -( ( adcData + dcOffset ) / divScale ); > > BTW I am getting frequent short data dropouts in the output display. I > have tracked that down to the possibility that I don't have enough RAM > (512MB) and am planning to add some more to see if that makes things better. > Adding more memory may help, but you might be trying to displaying too many data points. As WinSDR draws the screen it is not reading the TCP/IP packets for the network stack so you will loose data if it takes to long to draw the screen. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: Brett Nordgren brett3nt@............. Date: Wed, 19 Aug 2009 08:33:01 -0400 Larry, Many thanks for your information and suggstions. Regarding offset, I'll play with that some more with your information in hand. Regarding the data drop, your explanation fits what I am seeing reasonably well, though I am still trying to reconcile that with the fact that the current hour displays fine--the data must have gotten into the computer from the network OK. It's just when the screen refreshes that roughly a minute of the previously collected data gets dropped. If you look on your Current Seismicity page, you will see that the currently-writing line (which is now starting at 40 min after the hour) has no dropouts, but that same data will show a gap after my screen has been redrawn to start a new line. I may think about increasing the XP TCP/IP buffer to allow it to absorb the roughly 200k which can arrive during redraw. No idea if that can be done, or how to do it, or if it's the right answer, but expect I'll be able to find something on line. We would prefer to maintain the data rate if we can. We want to gather as much information on how the instruments are working as possible. I suppose we can drop the rate if there's no other answer. Thanks again, Brett At 07:41 PM 8/18/2009 -0700, you wrote: >Brett, > >>Hi All, >>I have been trying to provide calibration data for our 24-hour displays, >>by going to Settings > Channel Control > DC Offset, putting in a number, >>then watching how far the trace moves up/down. Knowing the instrument >>sensitivity per count, I can translate that into velocity units per >>line. I had been assuming that the number I was entering for the DC >>Offset is always representing counts, but now I am not so sure. >>Does anyone know how that works? > >Looking at the code the offset is applied to the A/D count and then >divided by a >number to get the trace to show up in the right Y location depending on >the Y Scale. >Here's the code: > >yLoc = lineOffset + -( ( adcData + dcOffset ) / divScale ); > >>BTW I am getting frequent short data dropouts in the output display. I >>have tracked that down to the possibility that I don't have enough RAM >>(512MB) and am planning to add some more to see if that makes things better. > >Adding more memory may help, but you might be trying to displaying too >many data >points. As WinSDR draws the screen it is not reading the TCP/IP packets >for the >network stack so you will loose data if it takes to long to draw the screen. > >Regards, >Larry Cochrane >Redwood City, PSN Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: Brett Nordgren brett3nt@............. Date: Wed, 19 Aug 2009 13:28:47 -0400 Larry, This may help track it down based on what I am seeing. I don't really need the answers, but thinking through them may help point us in the right direction. In the "View last 24 hours" 24 line display, what is the source for the 24th, currently drawing, line? What is the source for the previous 23 redrawn lines? What happens to the data from the 24th line when it completes and the screen refreshes? I am coming to believe that the data gap is being inserted during that process. Thanks much, Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: rbenitez@........ Date: Wed, 19 Aug 2009 13:06:39 -0500 (CDT) Hello Brett, In regard the data drop, I had this very same problem some time ago. At first it dropped a few seconds of data every hour, then it get worse and dropped as much as 3 minutes of data. I run concurrently in the same machine other programs, all of them take data from external sensors, (Wx, lightning, audio stream, APRS, etc.), I turned off one of each programs at a time in order to isolate the problem and the bad guy was the weather station program that took all cpu resources when updating its database, in that very moment the seismic data was dropped. I did not have a conclusive explanation of the cause, but was related to the writing/reading process of the virtual memory file in the hard disk. I solved the problem installing an USB memory stick and declared it as the residence of the paging virtual memory,(win XP), and also installed the logging SDR files in that volume. After this I totally solved the problem. My xp box is running all the programs and I doesn´t loose any data. It is a 3Ghz single core pentium, 2MB ram. It worked for me, hope it helps. Regards, Rolando PS You can monitor the disk, mem and cpu activity with the task manager or other similar program and check at the dropping time, chances are that one of any of them are at 100% and this may cause the data loss. rb > If you look on your Current Seismicity page, you will see that the > currently-writing line (which is now starting at 40 min after the hour) > has > no dropouts, but that same data will show a gap after my screen has been > redrawn to start a new line. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Not very big, but it's there From: Brett Nordgren brett3nt@............. Date: Wed, 19 Aug 2009 15:29:47 -0400 I think this is about the smallest we have recorded to date (except for the 1.9 @ 10Km from the vault) See: http://bnordgren.org/seismo/gif_images.htm On the "Instrument #1 high gain channel" image, at about 18:35 UCT Aug 19, 2009 is the LR surface wave from a Mag. 4.6 at 132 degrees (Indonesia). It's not that big a trace, but the long period seismic background is fairly low so it is easy to see. It must have been aimed straight at us. Regards, Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Not very big, but it's there - but maybe not From: Brett Nordgren brett3nt@............. Date: Wed, 19 Aug 2009 18:36:48 -0400 "I think this is about the smallest we have recorded to date (except for the 1.9 @ 10Km from the vault) " It now seems much more likely that we were seeing the 5.0 in Alaska with a predicted LR arrival time 51 seconds after the Indonesia 4.6, and a predicted amplitude more than 3x larger. Ah well, it's good but maybe not quite that good. Regards, Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinSDR question From: Brett Nordgren brett3nt@............. Date: Wed, 19 Aug 2009 22:34:03 -0400 Larry, At about 23:06 UTC I shut the computer down and added 1GB of additional memory, increasing RAM from 0.5GB to 1.5GB. At the moment it appears that the problem has either been greatly reduced or eliminated. Time will tell. Brett Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: meredith lamb paleoartifact@......... Date: Thu, 20 Aug 2009 12:35:41 -0600 Dave and Brett, Online Metals seems to have discontinued the main spring thickness of 0.12", and only lists a 0.16" thickness now. The 2.5" x 3.0" x 1/4" thick aluminum angle "L" bracket is also discontinued. The nearest size is 3" x 3" x 1/4" thick. The above are just cursory notes. Just for design thought fun....I'd almost think that a extruded aluminum (capital I) beam could potentially work at least for the main spring rear spring clamp on the one flat side...and then it crosses over to the other upright flat side...which with a added square piece attached to that upright flat top side (either in or outside) would provide a flat area for the smaller horizontal pivot spring. The (capital I) beam could ~ eliminate the presently used support square upright pieces on the base. Of course the (capital I) beam would still have to anchored to the base plate. Conversely, a (selected size) I beam could also be upright with front and rear end plates added...and henceforth..but may not be suitable as such. Of course the various sizes probably wouldn't fit the dimensions presently used without adding other "adjustment" pieces. Obviously, Online metal can cut to length (+- 1/8") at a reasonable added piece cost. Suspect you folks may have already pondered such. True, it probably wouldn't look "professionally made"; but if it reduces costs and works just as well; it might well be worth considering such. Any possibility of a "sneak peek" at the new untried smaller length size...I'am having a time visualizing such? Take care, Meredith On Sat, Aug 15, 2009 at 7:43 PM, Dave Nelson wrote: > Hi Meredith. > > The spring is cut to width on my personal shear and heat treated in the > home oven in the automatic cleaning mode. The heat treat significantly > increases the yield strength. The temperature is just right as measured with > a thermocouple. The width for the instrument pictured is 16 mm and thickness > is 12 mils. (Sorry for the mixed units -- our European friends will think > we can't make up our minds ) > (snip) > > > The overall size of the basic mechanism exclusive of the case is 4.5 x 9.5 > inches. I have a new (untried) design which will be 4.5 x 5 inches in a > somewhat different configuration which may allow for buoyancy compensation. > The new design is also easier to build or at least that is the goal. > > > Regards, Dave > > > > >
Dave and=A0Brett,

=A0

Online Metals seems to have discontinued the main spring thickness of = 0.12", and only lists a 0.16" thickness now.

=A0

The 2.5" x 3.0" x 1/4" thick aluminum angle "L&quo= t; bracket is also discontinued.=A0 The nearest size is 3" x 3" x= 1/4" thick.

=A0

The above are just cursory notes.

=A0

Just for design thought fun....I'd almost think that a extruded al= uminum=A0(capital I)=A0beam could potentially work at least for the main sp= ring=A0rear spring clamp on the one flat side...and then it crosses over to= the other upright flat side...which with a

added square piece attached to that upright flat top side (either in o= r outside) would provide a flat area for the smaller horizontal pivot sprin= g.=A0=A0The (capital I) beam could ~ eliminate the presently used=A0support= square upright pieces on the base.=A0 Of course the (capital I) beam would= still have to anchored to the base plate.=A0=A0 Conversely, a (selected si= ze) I beam=A0could also=A0be upright with front and rear end plates added..= ..and henceforth..but may not be suitable as such.=A0 Of course the various = sizes probably wouldn't fit the dimensions presently used without addin= g other "adjustment" pieces.=A0 Obviously, Online metal can cut t= o length (+- 1/8") at a reasonable added piece cost.=A0 Suspect you fo= lks may have

already pondered such.=A0 True, it probably wouldn't look "pr= ofessionally made"; but if it reduces costs and works just

as well; it might well be worth considering such.

=A0

Any possibility of a "sneak peek" at the new untried smaller= length size...I'am having a time visualizing such?

=A0

Take care, Meredith

=A0

=A0

=A0

=A0

On Sat, Aug 15, 2009 at 7:43 PM, Dave Nelson <davefnelson@.......> wrote:

Hi Meredith.

=A0

The spring is cut to width on my perso= nal shear and heat treated in the home oven in the automatic cleaning mode.= =A0 The heat treat significantly increases the yield strength. The temperat= ure is just right as measured with a thermocouple. The width for the instru= ment pictured is 16 mm and thickness is 12 mils.=A0 (Sorry for the mixed un= its -- our European friends will think we can't=A0 make up our minds )= =A0

(snip)

=A0

=A0=A0

The overall size of the basic mechanis= m exclusive of the case is 4.5 x 9.5 inches. I have a new (untried) design = which will be 4.5 x 5 inches in a somewhat different configuration which ma= y=A0allow for=A0 buoyancy compensation. =A0The new design is also easier to= build or at least that is the goal.

=A0

=A0

Regards, Dave

=A0

=A0

=A0

=A0
Subject: Jon, How about That 6.1 Shaker From: "Gary Lindgren" gel@................. Date: Thu, 20 Aug 2009 16:14:19 -0700 Jon, You were fairly close to that 6.1M earthquake in the Norwegian Sea. How did you equipment display this close by disturbance. Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com Check out Lastest Seismometer Reading cymonsplace.blogspot.com dtvtransitioninfo.blogspot.com Information on how to cope with the transition to DTV

Jon,

You were fairly close to that 6.1M earthquake in = the Norwegian Sea. How did you equipment display this close by = disturbance.

Gary

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

650-326-0655<= /span>

www.blue-eagle-technologies.com &nbs= p; Check out Lastest Seismometer = Reading

cymonsplace.blogspot.com =

dtvtransitioninfo.blogspot.com  = ;      Information on how to cope with the transition = to DTV

Subject: Re: Jon, How about That 6.1 Shaker From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 20 Aug 2009 23:30:38 +0000 Hi, The geophones at Hvammstangi, along with my lehman sensor test sensor did pick it up. It was also seen on my Hekla geophone, clearly. Due to wind noise, it was not seen as clearly on my Hvammstangi station. The best surfice wave signal was recorded on the lehman sensor. But I did also record surfice waves on my geophones. I have send the traces to the psn website. Here is my webpage with my helicorders, http://www.simnet.is/jonfr500/earthquake/tremoren.htm Hvammstangi was at the distance of ~1100 km, while Hekla was at the distance of ~1200 km. Regards. J=F3n Fr=EDmann.=20 On fim, 2009-08-20 at 16:14 -0700, Gary Lindgren wrote: > Jon, >=20 > You were fairly close to that 6.1M earthquake in the Norwegian Sea. > How did you equipment display this close by disturbance. >=20 > Gary >=20 > =20 >=20 > =20 >=20 > =20 >=20 > =20 >=20 > =20 >=20 > =20 >=20 > Gary Lindgren >=20 > 585 Lincoln Ave >=20 > Palo Alto CA 94301 >=20 > =20 >=20 > 650-326-0655 >=20 > =20 >=20 > www.blue-eagle-technologies.com Check out Lastest Seismometer > Reading >=20 > cymonsplace.blogspot.com=20 >=20 > dtvtransitioninfo.blogspot.com Information on how to cope with > the transition to DTV >=20 > =20 >=20 > =20 >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: Karl Cunningham karlc@.......... Date: Thu, 20 Aug 2009 21:11:57 -0700 Hi Brett, Please excuse the tardiness of this reply. Congratulations on your progress and good looking data. I can see from the photo on the web page roughly what the instrument is and how it's constructed. Other than the links already mentioned in this thread, have you published a description of the design and/or schematics of the electronics? Sorry if this has been covered here before. I've been away from monitoring the PSN list for some time, and a brief review of the archives didn't turn up a description. Curious minds want to know... Thanks. Regards, Karl Cunningham Brett Nordgren wrote: > Hello All, > > We just put up a Web page which displays some near real time outputs > from two of our experimental vertical feedback seismographs. There are > displays showing three different combinations of sensitivity and > low-pass filtering, which highlight different types of ground motion. > > http://bnordgren.org/seismo/gif_images.htm > > Currently these are updated every 30 minutes, though in the future we > may be able to reduce the update interval. As these are experimental > instruments, it may happen that they will occasionally be off line as we > make improvements. > > We sometime see short data dropouts, possibly related to the convoluted > data path we use to distribute the gif's. Data starts in Dave Nelson's > seismo vault in California, arrives via the Internet at my WinSDR client > in New Jersey where the gif files get generated. They then are uploaded > to my Web site, hosted in Pittsburgh... and so on. I am still working > to figure out the cause of the data drops. Suggestions welcomed. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Jon, How about That 6.1 Shaker From: Steinar Midtskogen steinar@............. Date: Fri, 21 Aug 2009 06:40:42 +0200 Jón Frímann writes: > Hi, > > The geophones at Hvammstangi, along with my lehman sensor test sensor > did pick it up. It was also seen on my Hekla geophone, clearly. Due to > wind noise, it was not seen as clearly on my Hvammstangi station. > > The best surfice wave signal was recorded on the lehman sensor. But I > did also record surfice waves on my geophones. > > I have send the traces to the psn website. > > Here is my webpage with my helicorders, > http://www.simnet.is/jonfr500/earthquake/tremoren.htm > > Hvammstangi was at the distance of ~1100 km, while Hekla was at the > distance of ~1200 km. My sensors (SEP + 3 channel 4.5 Hz geophone) were 1400 km away. Not a huge event. The seismometer recorded this: http://voksenlia.net/nytt/2009/jordskjelv-20090820.png (N-S 0.1 Hz lowpass) The geophone recorded a 2 second spike in all three directions at the arrival of the P wave, but this was nearly one minute after the calculated arrival time, so it might have been local noise. Otherwise, the quake only becomes clear on the geophone by some filtering, e.g. lowpass at 1 Hz. -- Steinar __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Fri, 21 Aug 2009 15:53:42 -0400 Hi Karl, Good to hear from you again. We're working on finishing up the docs and I'll keep you updated on what's happening. Can't run my CAD program and keep up with WinSDR at the same time (running at 200SPS), so am setting it up on another computer. Then back to documentation. For starters we just began by posting waveforms, but it shouldn't be too long before the docs are ready for prime time. Regards, Brett At 09:11 PM 8/20/2009 -0700, you wrote: >Hi Brett, > >Please excuse the tardiness of this reply. > >Congratulations on your progress and good looking data. > >I can see from the photo on the web page roughly what the instrument is >and how it's constructed. Other than the links already mentioned in this >thread, have you published a description of the design and/or schematics >of the electronics? > >Sorry if this has been covered here before. I've been away from monitoring >the PSN list for some time, and a brief review of the archives didn't turn >up a description. > >Curious minds want to know... > >Thanks. > >Regards, >Karl Cunningham Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: which seismometer? From: Robert Thomasson rlthomasson@......... Date: Fri, 21 Aug 2009 23:11:07 +0300 Jay, I'm kind of late jumping on the bandwagon here, but I'd like to also suggest adding the Volksmeter to your list of devices you're considering. I find the Volksmeter to be a very useful and practical instrument. For educational use it is not only a very good seismometer but demonstrates principles of pendulum physics and the capacitive sensor is also very interesting. The designer, Dr. Randall Peters of Mercer University in Georgia, is also an educator and you may find some synergy there. I have no first hand experience with the three other devices you mentioned and of course they also may be very suitable for your application. Regards, Bob Thomasson On Sat, Jul 25, 2009 at 12:23 AM, Jay Muza wrote: > Hi > I would like to purchase one of the inexpensive Lehman type seismometers > currently on the market. The three I am considering are the AS-1, the UK > School of Seismology SEP Seismometer System, and the Rockwave HS-3. Any > guidance..any at all...would be greatly appreciated. Thank you. > > > Dr. Jay Muza > Department of Physical Sciences > Broward College > Davie, FL 33314 > > Office: 954.201.6771 > Cell: 954.736.8231 > > jmuza@........... > > Please Note: Due to Florida's very broad public records law, most written > communications to or from College employees regarding College business are > public records, available to the public and media upon request. Therefore, > this email communication may be subject to public disclosure. > > Please consider the environment before printing this email. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > Jay,

I'm kind of late jumping on the bandwagon here, but I'd= like to also suggest adding the Volksmeter to your list of devices you'= ;re considering.=A0=A0 I find the Volksmeter to be a very useful and practi= cal instrument. =A0 For educational use it is not only a very good seismome= ter but demonstrates principles of pendulum physics=A0 and the capacitive s= ensor is also very interesting.=A0=A0

The designer, Dr. Randall Peters of Mercer University in Georgia, is al= so an educator and you=A0 may find some synergy there.

I have no first hand experience with the three other devices you mentio= ned and of course they also may be very suitable for your application.
<= br>Regards,

Bob Thomasson

On Sat, = Jul 25, 2009 at 12:23 AM, Jay Muza <jmuza@...........> wrote= :

Hi
I would like to purchase one of the inexpensive Lehman type seismometers cu= rrently on the market. =A0The three I am considering are the AS-1, the UK S= chool of Seismology SEP Seismometer System, and the Rockwave HS-3. =A0Any g= uidance..any at all...would be greatly appreciated. =A0Thank you.

Dr. Jay Muza
Department of Physical Sciences
Broward College
Davie, FL =A033314

Office: 954.201.6771
Cell: =A0 =A0954.736.8231

jmuza@...........

Please Note: Due to Florida's very broad public records law, most writt= en communications to or from College employees regarding College business a= re public records, available to the public and media upon request. Therefor= e, this email communication may be subject to public disclosure.

Please consider the environment before printing this email.

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See h= ttp://www.seismicnet.com/maillist.html for more information.

Subject: Re: Real time traces From: Karl Cunningham karlc@.......... Date: Fri, 21 Aug 2009 13:57:26 -0700 Hi Brett, Thanks for the reply. I have a mechanical design question about your sensor. Did you do any thing special with the spring anchor / clamp mechanism? For some time I've been focused on creep when leaf springs are clamped and stressed. The thought is that when the spring gets bent, the stress in the outer fibers of the spring will be beyond what the clamp can retain. This is especially true right where the spring emerges from the clamp. In some of my experiments this has caused noticeable hysteresis and creep. I surmise the same problem might occur when clamping flexures although the stress is bound to be much lower than in a leaf spring. Possibly some of this can be dealt with by stressing the spring and then clamping it, and maybe even artificially aging the assembly after clamping. Ideally the spring would be made with thicker ends for clamping but this is obviously impractical for our purposes. I'm curious if you did anything to help mitigate this effect. Karl Brett Nordgren wrote: > Hi Karl, > > Good to hear from you again. > > We're working on finishing up the docs and I'll keep you updated on > what's happening. Can't run my CAD program and keep up with WinSDR at > the same time (running at 200SPS), so am setting it up on another > computer. Then back to documentation. > > For starters we just began by posting waveforms, but it shouldn't be too > long before the docs are ready for prime time. > > Regards, > Brett > > At 09:11 PM 8/20/2009 -0700, you wrote: >> Hi Brett, >> >> Please excuse the tardiness of this reply. >> >> Congratulations on your progress and good looking data. >> >> I can see from the photo on the web page roughly what the instrument >> is and how it's constructed. Other than the links already mentioned in >> this thread, have you published a description of the design and/or >> schematics of the electronics? >> >> Sorry if this has been covered here before. I've been away from >> monitoring the PSN list for some time, and a brief review of the >> archives didn't turn up a description. >> >> Curious minds want to know... >> >> Thanks. >> >> Regards, >> Karl Cunningham > > Watch our wiggles > http://bnordgren.org/seismo/gif_images.htm > > or watch some very very good wiggles > http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: SPLIT SIGNAL PROBLEM From: AHrubetz@....... Date: Fri, 21 Aug 2009 18:34:49 EDT Some months ago I purchased a Geotech Instruments Helicorder RV-301B with the accompanying amplifier AR-320B. It works just fine when I drive it using one channel from one of Larry's older amp/filter boards. The input is from a Lehman-type horizontal detector utilizing a coil with 8k resistance. (hz1 detector). I normally have the Lehman hz1 output going into a second, newer version of Larry's amp/filter A/D boards, and then on to WinSDR. Here is my problem: I want to split the output from hz1 using a Y connector to both the WinSDR display and the helicorder so I can record analog and digital simultaneously. When I do this, the helicorder stylus goes dead and the CRT display from the amp/filter/AD board displays rhythmic amplitude spiking. There appeared to be an impedance mismatch, so an EE designed a buffer amplifier for me with two outputs. Unfortunately, when using the buffer amp, the helicorder stylus still is inoperative and the spiking again shows up on the CRT display from the amp/filter/AD board, just as before. I am at a loss at what to try next. The Geotech Instrument people say they are too busy to give me any advice. I am wondering if any of you using the RV301B helicorder has tried to use a split signal such as I described? I would appreciate any suggestions from the PSN family. Thanks and regards, Al Hrubetz Dallas, Texas
Some months ago I purchased a Geotech Ins= truments=20 Helicorder RV-301B with the accompanying amplifier AR-320B. It works= just=20 fine when I drive it using one channel from one of Larry's older amp/filte= r=20 boards. The input is from a Lehman-type horizontal=20 detector utilizing a coil with 8k resistance. (hz1 detector). = =20

I normally have the Lehman hz1 outpu= t going=20 into a second, newer version of Larry's amp/filter A/D boards,= and=20 then on to WinSDR.

Here is my problem: I want to split the= output=20 from hz1 using a Y connector to both the WinSDR display and the helicorder= so I=20 can record analog and digital simultaneously. When I do this, the=20 helicorder stylus goes dead and the CRT display from the amp/filter/AD boa= rd=20 displays rhythmic amplitude spiking.  There appeared to be = an=20 impedance mismatch, so an EE designed a buffer amplifier for me= with=20 two outputs. Unfortunately, when using the buffer amp, the helicorde= r=20 stylus still is inoperative and the spiking again shows up on the CRT disp= lay=20 from the amp/filter/AD board, just as before.

I am at a loss at what to try next. = The=20 Geotech Instrument people say they are too busy to give me any advice.&nbs= p; I=20 am wondering if any of you using the RV301B helicorder has tried to use a= split=20 signal such as I described? I would appreciate any suggestions from= the=20 PSN family.

Thanks and regards,

Al Hrubetz

Dallas, Texas

Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Fri, 21 Aug 2009 19:01:59 -0400 Hi Karl, Nothing particular at the ends. The stress builds from the center of the spring as you move toward the ends by maybe 25 or 30%, but nothing terribly exciting happens at the clamps. However there is another problem related to creep that we did address. By using relatively thin (0.012") spring material we kept the max stress level down to roughly 70-75,000 psi, while using material with a yield strength of 280,000 psi. By working at 1/4 of yield, creep is a non-issue. If you missed it, I ran through some numbers in my 8/16 message to Barry Lotz. In general, I feel that most home designs use springs which are much too thick and hence too highly stressed and prone to creep, etc. Of course if you use a thin spring, the mass has to go down too, but in a feedback instrument, that's all to the good. (up to a point, of course). Actually, Dave was the one who designed the spring. He may want to add something. Regards, Brett At 01:57 PM 8/21/2009 -0700, you wrote: >Hi Brett, > >Thanks for the reply. > >I have a mechanical design question about your sensor. Did you do any >thing special with the spring anchor / clamp mechanism? > >For some time I've been focused on creep when leaf springs are clamped and >stressed. The thought is that when the spring gets bent, the stress in the >outer fibers of the spring will be beyond what the clamp can retain. This >is especially true right where the spring emerges from the clamp. > >In some of my experiments this has caused noticeable hysteresis and creep. >I surmise the same problem might occur when clamping flexures although the >stress is bound to be much lower than in a leaf spring. > >Possibly some of this can be dealt with by stressing the spring and then >clamping it, and maybe even artificially aging the assembly after clamping. > >Ideally the spring would be made with thicker ends for clamping but this >is obviously impractical for our purposes. > >I'm curious if you did anything to help mitigate this effect. > >Karl Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: SPLIT SIGNAL PROBLEM From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 21 Aug 2009 23:17:59 +0000 Hello. The Y connector most likley does not carry the frequancy that your sensor is sending to the amp board. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote: > Some months ago I purchased a Geotech Instruments Helicorder RV-301B > with the accompanying amplifier AR-320B. It works just fine when I > drive it using one channel from one of Larry's older amp/filter > boards. The input is from a Lehman-type horizontal detector utilizing > a coil with 8k resistance. (hz1 detector). =20 > =20 > I normally have the Lehman hz1 output going into a second, > newer version of Larry's amp/filter A/D boards, and then on > to WinSDR. =20 > =20 > Here is my problem: I want to split the output from hz1 using a Y > connector to both the WinSDR display and the helicorder so I can > record analog and digital simultaneously. When I do this, the > helicorder stylus goes dead and the CRT display from the amp/filter/AD > board displays rhythmic amplitude spiking. There appeared to be an > impedance mismatch, so an EE designed a buffer amplifier for me with > two outputs. Unfortunately, when using the buffer amp, the helicorder > stylus still is inoperative and the spiking again shows up on the CRT > display from the amp/filter/AD board, just as before. > =20 > I am at a loss at what to try next. The Geotech Instrument people say > they are too busy to give me any advice. I am wondering if any of you > using the RV301B helicorder has tried to use a split signal such as I > described? I would appreciate any suggestions from the PSN family. > Thanks and regards, > =20 > Al Hrubetz > Dallas, Texas > =20 > =20 >=20 >=20 > ______________________________________________________________________ Hello.

The Y connector most likley does not carry the frequancy that your sensor is sending to the amp board.

Regards.
Jón Frímann.

On fös, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote:
Some months ago I purchased a Geotech Instruments Helicorder RV-301B with the accompanying amplifier AR-320B. It works just fine when I drive it using one channel from one of Larry's older amp/filter boards. The input is from a Lehman-type horizontal detector utilizing a coil with 8k resistance. (hz1 detector).

I normally have the Lehman hz1 output going into a second, newer version of Larry's amp/filter A/D boards, and then on to WinSDR.

Here is my problem: I want to split the output from hz1 using a Y connector to both the WinSDR display and the helicorder so I can record analog and digital simultaneously. When I do this, the helicorder stylus goes dead and the CRT display from the amp/filter/AD board displays rhythmic amplitude spiking.  There appeared to be an impedance mismatch, so an EE designed a buffer amplifier for me with two outputs. Unfortunately, when using the buffer amp, the helicorder stylus still is inoperative and the spiking again shows up on the CRT display from the amp/filter/AD board, just as before.

I am at a loss at what to try next. The Geotech Instrument people say they are too busy to give me any advice. I am wondering if any of you using the RV301B helicorder has tried to use a split signal such as I described? I would appreciate any suggestions from the PSN family.

Thanks and regards,

Al Hrubetz

Dallas, Texas

Subject: Re: SPLIT SIGNAL PROBLEM From: AHrubetz@....... Date: Fri, 21 Aug 2009 19:38:48 EDT Thanks, Jon. I am using the standard RCA type connectors and plugs,=20 including the Y connector. I have used the Y connector for many years in= the=20 past with a split signal to the amp/filter board and to a Omniscribe char= t=20 recorder with no problems. Regards, Al =20 =20 In a message dated 8/21/2009 6:18:32 P.M. Central Daylight Time, =20 jonfr@......... writes: Hello. The Y connector most likley does not carry the frequancy that your sensor= =20 is sending to the amp board. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote: =20 Some months ago I purchased a Geotech Instruments Helicorder RV-301B with= =20 the accompanying amplifier AR-320B. It works just fine when I drive it= =20 using one channel from one of Larry's older amp/filter boards. The input= is=20 from a Lehman-type horizontal detector utilizing a coil with 8k resistanc= e.=20 (hz1 detector). =20 I normally have the Lehman hz1 output going into a second, newer version= =20 of Larry's amp/filter A/D boards, and then on to WinSDR. =20 Here is my problem: I want to split the output from hz1 using a Y=20 connector to both the WinSDR display and the helicorder so I can record= analog and=20 digital simultaneously. When I do this, the helicorder stylus goes dead= =20 and the CRT display from the amp/filter/AD board displays rhythmic =20 amplitude spiking. There appeared to be an impedance mismatch, so an EE= designed=20 a buffer amplifier for me with two outputs. Unfortunately, when using th= e=20 buffer amp, the helicorder stylus still is inoperative and the spiking=20 again shows up on the CRT display from the amp/filter/AD board, just as= before.=20 =20 I am at a loss at what to try next. The Geotech Instrument people say=20 they are too busy to give me any advice. I am wondering if any of you us= ing =20 the RV301B helicorder has tried to use a split signal such as I described= ? =20 I would appreciate any suggestions from the PSN family.=20 Thanks and regards,=20 Al Hrubetz=20 Dallas, Texas=20 =20 ____________________________________
Thanks, Jon. I am using the standard RCA= type=20 connectors and plugs, including the Y connector. I have used the Y= =20 connector for many years in the past with a split signal to the amp/filter= board=20 and to a Omniscribe chart recorder with no problems.

Regards,

Al

In a message dated 8/21/2009 6:18:32 P.M. Central Daylight Time,=20 jonfr@......... writes:
Hello.

The Y connector most likley does not carry th= e=20 frequancy that your sensor is sending to the amp board.

Regards.<= BR>J=F3n=20 Fr=EDmann.

On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@........ wrote:=20
Some= months ago=20 I purchased a Geotech Instruments Helicorder RV-301B with the=20 accompanying amplifier AR-320B. It works just fine when I drive= it=20 using one channel from one of Larry's older amp/filter boards. = The=20 input is from a Lehman-type horizontal detector utilizing a= coil=20 with 8k resistance. (hz1 detector).   =20

I norm= ally have=20 the Lehman hz1 output going into a second, newer versio= n of=20 Larry's amp/filter A/D boards, and then on=20 to WinSDR.

Here= is my=20 problem: I want to split the output from hz1 using a Y connector= to=20 both the WinSDR display and the helicorder so I can record analog and= =20 digital simultaneously. When I do this, the helicorder stylus go= es=20 dead and the CRT display from the amp/filter/AD board displays rhythmi= c=20 amplitude spiking.  There appeared to be an impedance= =20 mismatch, so an EE designed a buffer amplifier for me with= two=20 outputs. Unfortunately, when using the buffer amp, the helicorde= r=20 stylus still is inoperative and the spiking again shows up on the CRT= =20 display from the amp/filter/AD board, just as before.=20

I am= at a=20 loss at what to try next. The Geotech Instrument people say= they=20 are too busy to give me any advice. I am wondering if any of you= using=20 the RV301B helicorder has tried to use a split signal such as I=20 described? I would appreciate any suggestions from the PSN=20 family.

Thanks= and=20 regards,

Al=20 Hrubetz

Dallas= ,=20 Texas

= =20

Subject: Re: SPLIT SIGNAL PROBLEM From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 21 Aug 2009 23:44:51 +0000 Hi RCA Y type connectors can send signal only one way. RCA Y type connectors do carry the frequancy that seismomters send to the amp board. But you need to make sure that the signal is going to right path trouth the Y connector. It might be a better solution for you to use RCA cable with one main connector with two out connectors. As that is just a simple caple split. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-21 at 19:38 -0400, AHrubetz@....... wrote: > Thanks, Jon. I am using the standard RCA type connectors and plugs, > including the Y connector. I have used the Y connector for many years > in the past with a split signal to the amp/filter board and to a > Omniscribe chart recorder with no problems. > Regards, > Al > =20 > In a message dated 8/21/2009 6:18:32 P.M. Central Daylight Time, > jonfr@......... writes: > =20 > Hello. > =20 > The Y connector most likley does not carry the frequancy that > your sensor is sending to the amp board. > =20 > Regards. > J=F3n Fr=EDmann. > =20 > On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote:=20 > =20 > > Some months ago I purchased a Geotech Instruments Helicorder > > RV-301B with the accompanying amplifier AR-320B. It works > > just fine when I drive it using one channel from one of > > Larry's older amp/filter boards. The input is from a > > Lehman-type horizontal detector utilizing a coil with 8k > > resistance. (hz1 detector). =20 > > I normally have the Lehman hz1 output going into a second, > > newer version of Larry's amp/filter A/D boards, and then on > > to WinSDR. =20 > > Here is my problem: I want to split the output from hz1 > > using a Y connector to both the WinSDR display and the > > helicorder so I can record analog and digital > > simultaneously. When I do this, the helicorder stylus goes > > dead and the CRT display from the amp/filter/AD board > > displays rhythmic amplitude spiking. There appeared to > > be an impedance mismatch, so an EE designed a buffer > > amplifier for me with two outputs. Unfortunately, when > > using the buffer amp, the helicorder stylus still is > > inoperative and the spiking again shows up on the CRT > > display from the amp/filter/AD board, just as before.=20 > > I am at a loss at what to try next. The Geotech Instrument > > people say they are too busy to give me any advice. I am > > wondering if any of you using the RV301B helicorder has > > tried to use a split signal such as I described? I would > > appreciate any suggestions from the PSN family.=20 > > Thanks and regards,=20 > > Al Hrubetz=20 > > Dallas, Texas=20 > > =20 > >=20 > >=20 > > ____________________________________________________________ >=20 >=20 > ______________________________________________________________________ Hi

RCA Y type connectors can send signal only one way. RCA Y type connectors do carry the frequancy that seismomters send to the amp board. But you need to make sure that the signal is going to right path trouth the Y connector.

It might be a better solution for you to use RCA cable with one main connector with two out connectors. As that is just a simple caple split.

Regards.
Jón Frímann.

On fös, 2009-08-21 at 19:38 -0400, AHrubetz@....... wrote:
Thanks, Jon. I am using the standard RCA type connectors and plugs, including the Y connector. I have used the Y connector for many years in the past with a split signal to the amp/filter board and to a Omniscribe chart recorder with no problems.

Regards,

Al

In a message dated 8/21/2009 6:18:32 P.M. Central Daylight Time, jonfr@......... writes:

Hello.

The Y connector most likley does not carry the frequancy that your sensor is sending to the amp board.

Regards.
Jón Frímann.

On fös, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote:

Some months ago I purchased a Geotech Instruments Helicorder RV-301B with the accompanying amplifier AR-320B. It works just fine when I drive it using one channel from one of Larry's older amp/filter boards. The input is from a Lehman-type horizontal detector utilizing a coil with 8k resistance. (hz1 detector).
I normally have the Lehman hz1 output going into a second, newer version of Larry's amp/filter A/D boards, and then on to WinSDR.
Here is my problem: I want to split the output from hz1 using a Y connector to both the WinSDR display and the helicorder so I can record analog and digital simultaneously. When I do this, the helicorder stylus goes dead and the CRT display from the amp/filter/AD board displays rhythmic amplitude spiking.  There appeared to be an impedance mismatch, so an EE designed a buffer amplifier for me with two outputs. Unfortunately, when using the buffer amp, the helicorder stylus still is inoperative and the spiking again shows up on the CRT display from the amp/filter/AD board, just as before.
I am at a loss at what to try next. The Geotech Instrument people say they are too busy to give me any advice. I am wondering if any of you using the RV301B helicorder has tried to use a split signal such as I described? I would appreciate any suggestions from the PSN family.
Thanks and regards,
Al Hrubetz
Dallas, Texas

Subject: Re: SPLIT SIGNAL PROBLEM From: AHrubetz@....... Date: Fri, 21 Aug 2009 20:03:14 EDT Hi Jon, Yes, I am using an RCA cable with one main connector with two out=20 connectors - a simple cable split - as you mentioned. Thanks and regards, Al =20 =20 In a message dated 8/21/2009 6:45:08 P.M. Central Daylight Time, =20 jonfr@......... writes: Hi RCA Y type connectors can send signal only one way. RCA Y type connectors= =20 do carry the frequancy that seismomters send to the amp board. But you ne= ed=20 to make sure that the signal is going to right path trouth the Y connecto= r. It might be a better solution for you to use RCA cable with one main=20 connector with two out connectors. As that is just a simple caple split. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-21 at 19:38 -0400, AHrubetz@....... wrote: =20 Thanks, Jon. I am using the standard RCA type connectors and plugs,=20 including the Y connector. I have used the Y connector for many years in= the =20 past with a split signal to the amp/filter board and to a Omniscribe chart= =20 recorder with no problems.=20 Regards,=20 Al=20 In a message dated 8/21/2009 6:18:32 P.M. Central Daylight Time,=20 jonfr@......... writes:=20 Hello. The Y connector most likley does not carry the frequancy that your sensor= =20 is sending to the amp board. Regards. J=F3n Fr=EDmann. On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote: =20 Some months ago I purchased a Geotech Instruments Helicorder RV-301B with= =20 the accompanying amplifier AR-320B. It works just fine when I drive it= =20 using one channel from one of Larry's older amp/filter boards. The input= is=20 from a Lehman-type horizontal detector utilizing a coil with 8k resistanc= e.=20 (hz1 detector). =20 I normally have the Lehman hz1 output going into a second, newer version= =20 of Larry's amp/filter A/D boards, and then on to WinSDR. =20 Here is my problem: I want to split the output from hz1 using a Y=20 connector to both the WinSDR display and the helicorder so I can record= analog and=20 digital simultaneously. When I do this, the helicorder stylus goes dead= =20 and the CRT display from the amp/filter/AD board displays rhythmic =20 amplitude spiking. There appeared to be an impedance mismatch, so an EE= designed=20 a buffer amplifier for me with two outputs. Unfortunately, when using th= e=20 buffer amp, the helicorder stylus still is inoperative and the spiking=20 again shows up on the CRT display from the amp/filter/AD board, just as= =20 before. =20 I am at a loss at what to try next. The Geotech Instrument people say = =20 they are too busy to give me any advice. I am wondering if any of you us= ing=20 the RV301B helicorder has tried to use a split signal such as I described= ? =20 I would appreciate any suggestions from the PSN family. =20 Thanks and regards, =20 Al Hrubetz =20 Dallas, Texas =20 =20 ____________________________________ =20 ____________________________________
Hi Jon,

    Yes, I am using an RCA= cable=20 with one main connector with two out connectors - a simple cable split -= as you=20 mentioned.

    Thanks and=20 regards,

    Al

In a message dated 8/21/2009 6:45:08 P.M. Central Daylight Time,=20 jonfr@......... writes:
Hi

RCA Y type connectors can send signal only one wa= y. RCA Y=20 type connectors do carry the frequancy that seismomters send to the amp= board.=20 But you need to make sure that the signal is going to right path trouth= the Y=20 connector.

It might be a better solution for you to use RCA cable= with=20 one main connector with two out connectors. As that is just a simple cap= le=20 split.

Regards.
J=F3n Fr=EDmann.

On f=F6s, 2009-08-21= at 19:38=20 -0400, AHrubetz@....... wrote:=20
Thanks= ,=20 Jon. I am using the standard RCA type connectors and plugs, incl= uding=20 the Y connector. I have used the Y connector for many years in= the=20 past with a split signal to the amp/filter board and to a Omniscribe= chart=20 recorder with no problems.

Regards,

Al

In a mess= age dated=20 8/21/2009 6:18:32 P.M. Central Daylight Time, jonfr@............ writes:

Hello.

The Y connector most likley does not carry the frequ= ancy=20 that your sensor is sending to the amp board.

<= FONT=20 size=3D2>Regards.
J=F3n Fr=EDmann.

On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... m wrote:=20

So= me months=20 ago I purchased a Geotech Instruments Helicorder RV-301B with= the=20 accompanying amplifier AR-320B. It works just fine when I dr= ive it=20 using one channel from one of Larry's older amp/filter boards.&nbs= p; The=20 input is from a Lehman-type horizontal detector utilizin= g a=20 coil with 8k resistance. (hz1 detector). =20   =20
I normal= ly have=20 the Lehman hz1 output going into a second, newer ve= rsion=20 of Larry's amp/filter A/D boards, and then on=20 to WinSDR.
Here is my=20 problem: I want to split the output from hz1 using a Y conne= ctor=20 to both the WinSDR display and the helicorder so I can record anal= og and=20 digital simultaneously. When I do this, the helicorder stylu= s goes=20 dead and the CRT display from the amp/filter/AD board displays rhy= thmic=20 amplitude spiking.  There appeared to be an impedan= ce=20 mismatch, so an EE designed a buffer amplifier for me= with=20 two outputs. Unfortunately, when using the buffer amp, the= =20 helicorder stylus still is inoperative and the spiking again shows= up on=20 the CRT display from the amp/filter/AD board, just as=20 before.=20
I am at= a=20 loss at what to try next. The Geotech Instrument people= say=20 they are too busy to give me any advice. I am wondering if= any of=20 you using the RV301B helicorder has tried to use a split signal su= ch as=20 I described? I would appreciate any suggestions from the PSN= =20 family.=20
Thanks= and=20 regards,=20
Al=20 Hrubetz=20
Dallas,= =20 Texas=20
= =20

=
Subject: Larry's AtoD board From: Richard Webb dwebb002@............. Date: Fri, 21 Aug 2009 20:22:24 -0400 Hi, Is the AtoD board provided by Larry Cochrane compatible with Amaseis or other software? I tried to find something in the archives but was not successful. Dick -- Richard Webb Raleigh, NC Farr and Webb Family Genealogy site: http://Genequake.com/Genealogy Family and Seismology site: http://Genequake.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Thank You Larry From: Jan Froom JDarwin@............. Date: Sat, 22 Aug 2009 07:48:27 -0700 I understand next week is Larry's Birthday. Wouldn't it be nice if those of us who enjoy and use the services Larry provides with this PSN web site... to send him a card... *with maybe a few bucks enclosed.* It costs to run the PSN site... yet Larry absorbs all the costs... we all really should help. You can send Larry a card at: Larry Cochrane 24 Garden Street Redwood City, CA. 94063 USA I understand next week is Larry's Birthday.

Wouldn't it be nice if those of us who enjoy and use the services Larry provides
with this PSN web site... to send him a card... with maybe a few bucks enclosed.
It costs to run the PSN site... yet Larry absorbs all the costs... we all really should help.

You can send Larry a card at:
Larry Cochrane
24 Garden Street
Redwood City, CA. 94063
USA

Subject: A spring's constant From: "tchannel" tchannel@............ Date: Sat, 22 Aug 2009 12:07:39 -0600 Hi Folks, This question maybe a simple one........Is a spring's = constant, its "stiffness" I have a formulas for finding the constant, = but I am unclear what it is. As an example, I hung a spring, with no addition mass, and I measured = how much force is required to pull it 2". Next I add 100g of weight to = the end of the spring, and measure the force it took to move it 2". = The force was now different. Easier? Is this the change in the = springs constant? I did this with several different weights, and using the formula = K=3Dmg/x, I noted the different constants. I was surprised that these = numbers were not close, they were not "constant". On one spring this K decreased as I added weight, On a different = spring the K increased as I added weight. I also would like to a formula to find the frequency of a spring. Please if you can, would you include an example, showing your math = figures? I am not very good at math and the examples help a lot. Thanks, Ted
   Hi Folks, This = question=20 maybe a simple one........Is a spring's constant, its = "stiffness"   I=20 have a formulas for finding the constant, but I am unclear what it=20 is.

As an example, I hung a spring, with no = addition=20 mass, and I measured how much force is required to pull it = 2".   Next=20 I add 100g of weight to the end of the spring, and measure the force it = took to=20 move it 2".   The force was now different. =20 Easier?   Is this the change in the springs = constant?

I did this with several different = weights, and=20 using the formula K=3Dmg/x, I noted the different constants.   = I was=20 surprised that these numbers were not close, they were not=20 "constant".

On one spring this K decreased as I = added=20 weight,   On a different spring the K increased as I added=20 weight.

I also would like to a formula to find = the=20 frequency of a spring.

Please if you can, would you include an = example,=20 showing your math figures?   I am not very good at math and = the=20 examples help a lot.

Thanks, Ted
Subject: Re: Thank You Larry From: Robert Thomasson rlthomasson@......... Date: Sat, 22 Aug 2009 22:10:10 +0300 Jan, Didn't know it was Larry's birthday coming up but I've been thinking similar thoughts lately about taking much more from the psn than I'll ever be able to return. I think we can also send money via his website. Instead of a payment for hardware I think we should be able to send a donation. On Sat, Aug 22, 2009 at 5:48 PM, Jan Froom wrote: > I understand next week is Larry's Birthday. > > Wouldn't it be nice if those of us who enjoy and use the services Larry > provides > with this PSN web site... to send him a card... *with maybe a few bucks > enclosed.* > It costs to run the PSN site... yet Larry absorbs all the costs... we all > really should help. > > You can send Larry a card at: > Larry Cochrane > 24 Garden Street > Redwood City, CA. 94063 > USA > > Jan,

Didn't know it was Larry's birthday coming up but I'= ;ve been thinking similar thoughts lately about taking much more from the p= sn than I'll ever be able to return.=A0 I think we can also send money = via his website.=A0 Instead of a payment for hardware I think we should be = able to send a donation.

On Sat, Aug 22, 2009 at 5:48 PM, Jan Froom <= span dir=3D"ltr"><JDarwin@launc= hnet.com> wrote:
=20
I understand next week is Larry's Birthday.

Wouldn't it be nice if those of us who enjoy and use the services Larry provides
with this PSN web site... to send him a card... with maybe a few bucks enclosed.=A0
It costs to run the PSN site... yet Larry absorbs all the costs... we all really should help.

You can send Larry a card at:
Larry Cochrane
24 Garden Street
Redwood City, CA. 94063
USA

Subject: Re: A spring's constant From: Tangazazen@....... Date: Sat, 22 Aug 2009 15:31:24 EDT Hi, The subject of springs constantly pops up. It might be of interest to look at the spring from the base of an old angle poise lamp. This is in fact a negative length spring for small loads; the intersect passes though zero to become a positive length as the load increases. It is possible to adjust a seismometer fitted with such a spring to give a period of 15 seconds but it will not remain in this state for long. As in all springs the elastic stain is slowly replaced by creep strain. In general the mechanism of creep is divided into dislocation and diffusion creep both of which are temperature dependent . Dislocation creep is usually at a max for a new spring and hence the use of an old angle poise lamp spring. Regards Martin
Hi,

The subject of springs constantly pops up. It might be of inter= est to=20 look at the spring from the base of an old angle poise lamp. This is in fa= ct a=20 negative length spring for small loads; the intersect passes though= zero to=20 become a positive length as the load increases. It is possible to adjust= a=20 seismometer fitted with such a spring to give a period of 15=20 seconds but it will not remain in this state for long.  As= in all=20 springs the elastic stain is slowly replaced by creep strain. In=20 general the mechanism of creep is divided into dislocation and diffus= ion=20 creep both of which are temperature dependent . Dislocation creep is usual= ly at=20 a max for a new spring and hence the use of an old angle poise lamp spring= ..=20

Regards Martin
Subject: Re: Real time traces From: Barry Lotz barry_lotz@............. Date: Sat, 22 Aug 2009 14:39:13 -0700 (PDT) Brett et al I think this discussion has been made before but... I was trying to decide = the best displacement sensor style. What was the problem with inductive sty= le sensors? I agree LVDT's can have clearance issues. VRTD's - I like, but = someone had a problem with it but I can't remember what the reason was. I u= se it on a small version of STM style sensor. I do get an occasional low fr= equency oscillation which I can't nail down (~0.01 hz). I tentatively attri= bute to maybe my triple feedback is slightly off. I would use a capacitive = sensor but they seem so large to get a nominal capacitance value. Especiall= y when one is trying to design a small unit.=20 Barry =A0 --- On Fri, 8/21/09, Brett Nordgren wrote: From: Brett Nordgren Subject: Re: Real time traces To: psn-l@.............. Date: Friday, August 21, 2009, 4:01 PM Hi Karl, Nothing particular at the ends.=A0 The stress builds from the center of the= spring as you move toward the ends by maybe 25 or 30%, but nothing terribl= y exciting happens at the clamps.=A0 However there is another problem relat= ed to creep that we did address.=A0 By using relatively thin (0.012") sprin= g material we kept the max stress level down to roughly 70-75,000 psi, whil= e using material with a yield strength of 280,000 psi.=A0 By working at 1/4= of yield, creep is a non-issue.=A0 If you missed it, I ran through some nu= mbers in my 8/16 message to Barry Lotz. In general, I feel that most home designs use springs which are much too th= ick and hence too highly stressed and prone to creep, etc.=A0 Of course if = you use a thin spring, the mass has to go down too, but in a feedback instr= ument, that's all to the good. (up to a point, of course). Actually, Dave was the one who designed the spring.=A0 He may want to add s= omething. Regards, Brett At 01:57 PM 8/21/2009 -0700, you wrote: > Hi Brett, >=20 > Thanks for the reply. >=20 > I have a mechanical design question about your sensor. Did you do any thi= ng special with the spring anchor / clamp mechanism? >=20 > For some time I've been focused on creep when leaf springs are clamped an= d stressed. The thought is that when the spring gets bent, the stress in th= e outer fibers of the spring will be beyond what the clamp can retain. This= is especially true right where the spring emerges from the clamp. >=20 > In some of my experiments this has caused noticeable hysteresis and creep= .. I surmise the same problem might occur when clamping flexures although th= e stress is bound to be much lower than in a leaf spring. >=20 > Possibly some of this can be dealt with by stressing the spring and then = clamping it, and maybe even artificially aging the assembly after clamping. >=20 > Ideally the spring would be made with thicker ends for clamping but this = is obviously impractical for our purposes. >=20 > I'm curious if you did anything to help mitigate this effect. >=20 > Karl Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Brett et al
I think this discussion has be= en made before but... I was trying to decide the best displacement sensor s= tyle. What was the problem with inductive style sensors? I agree LVDT's can= have clearance issues. VRTD's - I like, but someone had a problem with it = but I can't remember what the reason was. I use it on a small version of ST= M style sensor. I do get an occasional low frequency oscillation which I ca= n't nail down (~0.01 hz). I tentatively attribute to maybe my triple feedba= ck is slightly off. I would use a capacitive sensor but they seem so large = to get a nominal capacitance value. Especially when one is trying to design= a small unit.
Barry

--- On Fri, 8/21/09, Brett Nor= dgren <brett3nt@.............> wrote:

From: Brett Nordgren <brett3nt@.............>
Subject: = Re: Real time traces
To: psn-l@..............
Date: Friday, August 21= , 2009, 4:01 PM

Hi Karl,

Nothing par= ticular at the ends. The stress builds from the center of the spring = as you move toward the ends by maybe 25 or 30%, but nothing terribly exciti= ng happens at the clamps. However there is another problem related to= creep that we did address. By using relatively thin (0.012") spring = material we kept the max stress level down to roughly 70-75,000 psi, while = using material with a yield strength of 280,000 psi. By working at 1/= 4 of yield, creep is a non-issue. If you missed it, I ran through som= e numbers in my 8/16 message to Barry Lotz.

In general, I feel that = most home designs use springs which are much too thick and hence too highly= stressed and prone to creep, etc. Of course if you use a thin spring, the mass has to go down too, but in a feedback instrument, that's = all to the good. (up to a point, of course).

Actually, Dave was the = one who designed the spring. He may want to add something.

Reg= ards,
Brett

At 01:57 PM 8/21/2009 -0700, you wrote:
&g= t; Hi Brett,
>
> Thanks for the reply.
>
> I have= a mechanical design question about your sensor. Did you do any thing speci= al with the spring anchor / clamp mechanism?
>
> For some time= I've been focused on creep when leaf springs are clamped and stressed. The= thought is that when the spring gets bent, the stress in the outer fibers = of the spring will be beyond what the clamp can retain. This is especially = true right where the spring emerges from the clamp.
>
> In som= e of my experiments this has caused noticeable hysteresis and creep. I surm= ise the same problem might occur when clamping flexures although the stress is bound to be much lower than in a leaf spring.
>
> P= ossibly some of this can be dealt with by stressing the spring and then cla= mping it, and maybe even artificially aging the assembly after clamping.>
> Ideally the spring would be made with thicker ends for clamp= ing but this is obviously impractical for our purposes.
>
> I'= m curious if you did anything to help mitigate this effect.
>
>= ; Karl

Watch our wiggles
http://bnordgren.org/seismo/gif_images.htm=

or watch some very very good wiggles
http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html

__________________________________________________________
Public Seismic Network Mailing List (PSN-L)

To leave this list emai= l PSN-L-REQUEST@.............. with the = body of the message (first line only): unsubscribe
See http://www.seismicnet.= com/maillist.html for more information.
Subject: Re: A spring's constant From: "Geoffrey" gmvoeth@........... Date: Sat, 22 Aug 2009 15:23:05 -0700 Hello Group; Does this mean that although I set the Hs10-1 vertical to its center point prior to burying it in the ground a couple years ago I should occasionally dig it up and reset the center point since it has a spring inside ?? Also, would it hurt to open it up and increase its mechanicanical damping and water resistance by filling its cavity with low viscosity machine oil ( like 3 in one oil) ? Like, does oil eat the insulation off the wires even tho it protects metal against water a bit better than nothing ? Is there a "water getter" you might put into an oil bath to chemically react and neutralize any water present at the bottom of the oil ? Ill just set back and listen to any responses. I have heard you can dismantle a handgun and put it in an oil bath in a jar or something then 20 years later dig it up reassemble it and its as good as new ? Might work for geophones too ? Best Regards; geoff ----- Original Message ----- From: To: Sent: Saturday, August 22, 2009 12:31 PM Subject: Re: A spring's constant Hi, The subject of springs constantly pops up. It might be of interest to look at the spring from the base of an old angle poise lamp. This is in fact a negative length spring for small loads; the intersect passes though zero to become a positive length as the load increases. It is possible to adjust a seismometer fitted with such a spring to give a period of 15 seconds but it will not remain in this state for long. As in all springs the elastic stain is slowly replaced by creep strain. In general the mechanism of creep is divided into dislocation and diffusion creep both of which are temperature dependent . Dislocation creep is usually at a max for a new spring and hence the use of an old angle poise lamp spring. Regards Martin __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: A spring's constant From: "Geoffrey" gmvoeth@........... Date: Sat, 22 Aug 2009 15:51:13 -0700 There is a company called Century spring which I believe you can find knowledge about their springs. It is my personal experience with extension springs that if they are a simple coil of a certain diameter wire with a certain diameter coil it will be fairly linear in ounces per inch or inch per ounces as the constant so the formula is linear like y=mx+b as seen in most algebra books. Sometimes they have pretension on them so like they do not extend 10 inches to get one second of period but 9 because one inch of tension is already in the spring. You need to subtract the no weight length from the weighted length and possibly add any pretension length. if you look at overall spring length. Also I have found the pendulum formula good for linear springs Period = 2*Pi* SQR(INCHESextension/386.0885827averagegravityat sea level) Which means with any weight which extends a spring about 10 inches will give you about one second of period. Id like to have a 20 foot spring with this idea. With a one ton weight (2000 lbs Avdp.) Avodupoise not Troy. Avi.....Oh Darn Darn Darn I just cant spell. Thats all I know which isnt much. Best regards; geoff ----- Original Message ----- From: "tchannel" To: "psn" Sent: Saturday, August 22, 2009 11:07 AM Subject: A spring's constant Hi Folks, This question maybe a simple one........Is a spring's constant, its "stiffness" I have a formulas for finding the constant, but I am unclear what it is. As an example, I hung a spring, with no addition mass, and I measured how much force is required to pull it 2". Next I add 100g of weight to the end of the spring, and measure the force it took to move it 2". The force was now different. Easier? Is this the change in the springs constant? I did this with several different weights, and using the formula K=mg/x, I noted the different constants. I was surprised that these numbers were not close, they were not "constant". On one spring this K decreased as I added weight, On a different spring the K increased as I added weight. I also would like to a formula to find the frequency of a spring. Please if you can, would you include an example, showing your math figures? I am not very good at math and the examples help a lot. Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: ChrisAtUpw@....... Date: Sat, 22 Aug 2009 19:06:51 EDT In a message dated 22/08/2009, barry_lotz@............. writes: I was trying to decide the best displacement sensor style. What was the problem with inductive style sensors? Hi Barry, Ordinary amateur coil + magnet sensors tend to be more limited by noise. You can't use them to correct position drift with temperature. The use of NdFeB quad magnet blocks will give a greatly increased output compared to Alnico U magnets. I agree LVDT's can have clearance issues. This depends on whether you use commercial sensors or design your own. You can buy commercial sensors with a wide clearance. Schaevitz produce them amongst others. Commercial LVDTs seem to have quite noisy electronic detector circuits, but good designs are available VRTD's - I like, but someone had a problem with it but I can't remember what the reason was. I don't know of any problems / can't remember hearing of any. You do need the moving plate to considerably overlap the field coil poles. I use it on a small version of STM style sensor. I do get an occasional low frequency oscillation which I can't nail down (~0.01 hz). I tentatively attribute to maybe my triple feedback is slightly off. I would use a capacitive sensor but they seem so large to get a nominal capacitance value. Especially when one is trying to design a small unit. A capacitance of ~10 pF is commonly used. You can get much lower overall noise with a capacitative system - so long as you use sine wave excitation. The common problem with the variable plate separation design, is the large change possible in the air damping as the plate gap varies. The allowable movement is small and this is better used in a feedback design. Plates with drilled array of holes may be used. A shaded pole design with the shadow plate moving parallel to the other plates may be used. These can be used in open circuit or feedback designs and can measure movements from nano metres to metres. See also LCDTs. Could this be an undamped torsional oscillation? Alternatively, are you sure that it is correctly damped? What sort of capacitors did you use? Sounds more like a phase shift problem? Regards, Chris Chapman
In a message dated 22/08/2009, barry_lotz@............. writes:
I was=20 trying to decide the best displacement sensor style. What was the proble= m with=20 inductive style sensors?
Hi Barry,

    Ordinary amateur coil + magnet sensors tend= to be=20 more limited by noise. You can't use them to correct position drift with= =20 temperature. The use of NdFeB quad magnet blocks will give a greatly incre= ased=20 output compared to Alnico U magnets.
I agree=20 LVDT's can have clearance issues.
    This depends on whether you use commercial se= nsors=20 or design your own. You can buy commercial sensors with a wide clearance.= =20 Schaevitz produce them amongst others. Commercial LVDTs seem to have quite= noisy=20 electronic detector circuits, but good designs are available
VRTD's -=20 I like, but someone had a problem with it but I can't remember what the= reason=20 was.
    I don't know of any problems / can't remember= =20 hearing of any. You do need the moving plate to considerably overlap the= field=20 coil poles.
I use it=20 on a small version of STM style sensor. I do get an occasional low frequ= ency=20 oscillation which I can't nail down (~0.01 hz). I tentatively attribute= to=20 maybe my triple feedback is slightly off. I would use a capacitive senso= r but=20 they seem so large to get a nominal capacitance value. Especially when= one is=20 trying to design a small unit.

    A capacitance of ~10 pF is commonly used. You= can=20 get much lower overall noise with a capacitative system - so long as you= use=20 sine wave excitation. The common problem with the variable plate sepa= ration=20 design, is the large change possible in the air damping as the plate= gap=20 varies. The allowable movement is small and this is better used in a= =20 feedback design. Plates with drilled array of holes may be used. A sh= aded=20 pole design with the shadow plate moving parallel to the other plates= may=20 be used. These can be used in open circuit or feedback designs and can mea= sure=20 movements from nano metres to metres. See also LCDTs.

    Could this be an undamped torsional oscillati= on?=20 Alternatively, are you sure that it is correctly damped? What sort of capa= citors=20 did you use? Sounds more like a phase shift problem?

    Regards,

    Chris Chapman
Subject: Re: Real time traces From: Brett Nordgren brett3nt@............. Date: Sat, 22 Aug 2009 20:30:35 -0400 Barry, The main problem that I saw with using inductive sensors in a feedback design is that their excitation frequency tended to be relatively low. After demodulating there is a lot of residual 2xcarrier which needs to be filtered. To filter it out adds a great amount of phase shift in the loop, right near the gain crossover frequency, (the instrument's high-frequency corner) that annoys the feedback loop no end and makes it difficult or impossible to crank up the loop to really do its job. If you try, it oscillates. Capacitive sensors operate at much higher frequencies and so the residue is much easier to filter in a way that allows the feedback loop to work really well without oscillating. Ours uses a quasi-square wave drive, so the filtering is also less than it might otherwise have to be. I sort of agree with Chris, that a sine-wave drive seems like it would work much better, but Dave's design really works--a lot better than I could have imagined. Capacitive sensors can work well with very small capacitors, ours is roughly 48pF and 2.5" x 3", which is probably significantly larger than necessary. When I look at the Nanometrics Trillium compact, which packs three force-balance sensors into a can slightly over 5" high and 3.5" dia, I have the feeling that good capacitive sensors can be made quite small. Regards, Brett At 02:39 PM 8/22/2009 -0700, you wrote: >Brett et al >I think this discussion has been made before but... I was trying to decide >the best displacement sensor style. What was the problem with inductive >style sensors? I agree LVDT's can have clearance issues. VRTD's - I like, >but someone had a problem with it but I can't remember what the reason >was. I use it on a small version of STM style sensor. I do get an >occasional low frequency oscillation which I can't nail down (~0.01 hz). I >tentatively attribute to maybe my triple feedback is slightly off. I would >use a capacitive sensor but they seem so large to get a nominal >capacitance value. Especially when one is trying to design a small unit. >Barry > Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Real time traces From: "Geoffrey" gmvoeth@........... Date: Sat, 22 Aug 2009 18:20:57 -0700 Hello PSN; for you radio buffs. Id think you'd make the capacitive sensor as part of some kind of oscillator circuit like (colpits or heartly), not sure which. or something like that then you'd make a FM modulated transmitter at some fundamental frequency. If you can do so without violating FCC law simply transmit that to a receiver where it is FM demodulated to get your trace. No wires between sensor and receiver. The smaller the cap the higher the freq for any given reactance value. You must isolate the oscillator through buffering so loads do not change frequency. You must tightly regulate voltage also directly to the oscillator. And it all must be tightly shielded. But in the USA you most probably are limited to what frequencies you can use less than 5 milliwatts into the oscillator itself. With a quarter wave whip you get maybe 7dbv of gain so at most 5mw effective radiated power in the vertical plane. It is quieter in the horizontal plane but then with a three element yagi-uda antenna you get more gain and better directional capabilities. At 100MHZ ( FM BAND) the driven element is like 4 feet 10 and some odd inches long. The reflector is like 100% speed of light and the director is like 90% the speed of light and like the spacing is like 0.2 wavelength at the driven parameters like 98.5% light speed. You need no test equipment just a good meter bar with mm markings. Gamma match it and a baluns into a 50 ohm coaxial cable and to the Antenna maybe 50 ft away. For you science peoples its probably more complex than this. I have heard of flea power going around the world if you have a very good high class receiver. Something the NSA might use. I was told by a special forces cheif the fastest way to die is to play with radio transmitters so I guess a ham license may be a must before you try such a thing in the USA. Or so it seems. geoff ----- Original Message ----- From: "Brett Nordgren" To: Sent: Saturday, August 22, 2009 5:30 PM Subject: Re: Real time traces Barry, The main problem that I saw with using inductive sensors in a feedback design is that their excitation frequency tended to be relatively low. After demodulating there is a lot of residual 2xcarrier which needs to be filtered. To filter it out adds a great amount of phase shift in the loop, right near the gain crossover frequency, (the instrument's high-frequency corner) that annoys the feedback loop no end and makes it difficult or impossible to crank up the loop to really do its job. If you try, it oscillates. Capacitive sensors operate at much higher frequencies and so the residue is much easier to filter in a way that allows the feedback loop to work really well without oscillating. Ours uses a quasi-square wave drive, so the filtering is also less than it might otherwise have to be. I sort of agree with Chris, that a sine-wave drive seems like it would work much better, but Dave's design really works--a lot better than I could have imagined. Capacitive sensors can work well with very small capacitors, ours is roughly 48pF and 2.5" x 3", which is probably significantly larger than necessary. When I look at the Nanometrics Trillium compact, which packs three force-balance sensors into a can slightly over 5" high and 3.5" dia, I have the feeling that good capacitive sensors can be made quite small. Regards, Brett At 02:39 PM 8/22/2009 -0700, you wrote: >Brett et al >I think this discussion has been made before but... I was trying to decide >the best displacement sensor style. What was the problem with inductive >style sensors? I agree LVDT's can have clearance issues. VRTD's - I like, >but someone had a problem with it but I can't remember what the reason >was. I use it on a small version of STM style sensor. I do get an >occasional low frequency oscillation which I can't nail down (~0.01 hz). I >tentatively attribute to maybe my triple feedback is slightly off. I would >use a capacitive sensor but they seem so large to get a nominal >capacitance value. Especially when one is trying to design a small unit. >Barry > Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Thank You Larry From: Larry Cochrane lcochrane@.............. Date: Sat, 22 Aug 2009 21:25:15 -0700 Jan, my birthday is in January not next week. Regards, Larry Cochrane Redwood City, PSN Jan Froom wrote: > I understand next week is Larry's Birthday. > > Wouldn't it be nice if those of us who enjoy and use the services Larry > provides > with this PSN web site... to send him a card... *with maybe a few bucks > enclosed.* > It costs to run the PSN site... yet Larry absorbs all the costs... we > all really should help. > > You can send Larry a card at: > Larry Cochrane > 24 Garden Street > Redwood City, CA. 94063 > USA > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Thank You Larry From: Jan Froom JDarwin@............. Date: Sat, 22 Aug 2009 22:33:11 -0700 Shoot.... so I guessed wrong. :-D *None the less... what I said about sending Larry a donation still applies*. Then how about.... A Very Merry /Unbirthday/ to Larry! Larry Cochrane wrote: > Jan, my birthday is in January not next week. > > Regards, > Larry Cochrane > Redwood City, PSN > > > Jan Froom wrote: >> I understand next week is Larry's Birthday. >> >> Wouldn't it be nice if those of us who enjoy and use the services >> Larry provides >> with this PSN web site... to send him a card... *with maybe a few >> bucks enclosed.* It costs to run the PSN site... yet Larry absorbs >> all the costs... we all really should help. >> >> You can send Larry a card at: >> Larry Cochrane >> 24 Garden Street >> Redwood City, CA. 94063 >> USA >> >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > Shoot.... so I guessed wrong. :-D
None the less... what I said about sending Larry a donation still applies.
Then how about.... A Very Merry Unbirthday to Larry!

Larry Cochrane wrote:
Jan, my birthday is in January not next week.

Regards,
Larry Cochrane
Redwood City, PSN

Jan Froom wrote:

I understand next week is Larry's Birthday.

Wouldn't it be nice if those of us who enjoy and use the services Larry provides
with this PSN web site... to send him a card... *with maybe a few bucks enclosed.* It costs to run the PSN site... yet Larry absorbs all the costs... we all really should help.

You can send Larry a card at:
Larry Cochrane
24 Garden Street
Redwood City, CA. 94063
USA

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

Subject: Drop Outs From: Richard Webb dwebb002@............. Date: Sun, 23 Aug 2009 14:18:02 -0400 Hi, Need some advice. I am using larry's ATD board ver 1.4 with the latest version of WINSDR on a gateway P5-2000 (1997 vintage) with Win 2000, 256 memory and a 160 GB HD. I have also observed the following with a Dell Latitude laptop running XP with significantly more memory and processor speed. The trace moves along the screen displaying properly for a few minutes, all of the lines disappear and then reappear, except that the recent portion of the trace is a straight green line. The trace continues to display properly. The result is a series of green lines and traces. The length of the green line, which is dead straight, can vary from a minute or two to tens of minutes. It happens on all channels simultaneously. I have removed all other programs, stopped all updating programs and even tried to use a thumb drive for storage. No effect except that the thumb seemed to have more green lines. Help, Dick -- Richard Webb Raleigh, NC Farr and Webb Family Genealogy site: http://Genequake.com/Genealogy Family and Seismology site: http://Genequake.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Drop Outs From: Barry Lotz barry_lotz@............. Date: Mon, 24 Aug 2009 05:03:48 -0700 (PDT) Hi Dick I have had the same symptom on occasion, though not to frequently. I notice= d Brett's/Dave's display posted also had one. I have seen a GIF error messa= ge in my log viewer which might have something to do with it. Regards Barry --- On Sun, 8/23/09, Richard Webb wrote: From: Richard Webb Subject: Drop Outs To: "psn-l@.............." Date: Sunday, August 23, 2009, 11:18 AM Hi, Need some advice.=A0 I am using larry's ATD board ver 1.4 with the latest v= ersion of WINSDR=A0 on a gateway P5-2000 (1997 vintage) with Win 2000, 256 = memory and a 160 GB HD.=A0 I have also observed the following with a Dell L= atitude laptop running XP with significantly more memory and processor spee= d. The trace moves along the screen displaying properly for a few minutes, all= of the lines disappear and then reappear, except that the recent portion o= f the trace is a straight green line.=A0 The trace continues to display pro= perly.=A0 The result is a series of green lines and traces.=A0 The length o= f the green line, which is dead straight, can vary from a minute or two to = tens of minutes.=A0 It happens on all channels simultaneously. I have removed all other programs, stopped all updating programs and even t= ried to use a thumb drive for storage.=A0 No effect except that the thumb s= eemed to have more green lines. Help, Dick -- Richard Webb Raleigh, NC Farr and Webb Family Genealogy site:=A0 http://Genequake.com/Genealogy Family and Seismology site:=A0 http://Genequake.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Hi Dick
I have had the same symptom on occ= asion, though not to frequently. I noticed Brett's/Dave's display posted al= so had one. I have seen a GIF error message in my log viewer w= hich might have something to do with it.
Regards
Barry

---= On Sun, 8/23/09, Richard Webb <dwebb002@.............>= wrote:

From: Richard Webb <dwebb002@ear= thlink.net>
Subject: Drop Outs
To: "psn-l@.............." <psn-= l@..............>
Date: Sunday, August 23, 2009, 11:18 AM

Hi,
Need some advice. I am using larry's ATD = board ver 1.4 with the latest version of WINSDR on a gateway P5-2000 = (1997 vintage) with Win 2000, 256 memory and a 160 GB HD. I have also observed the following with a Dell Latitude laptop running XP with signifi= cantly more memory and processor speed.

The trace moves along the sc= reen displaying properly for a few minutes, all of the lines disappear and = then reappear, except that the recent portion of the trace is a straight gr= een line. The trace continues to display properly. The result i= s a series of green lines and traces. The length of the green line, w= hich is dead straight, can vary from a minute or two to tens of minutes.&nb= sp; It happens on all channels simultaneously.

I have removed all ot= her programs, stopped all updating programs and even tried to use a thumb d= rive for storage. No effect except that the thumb seemed to have more= green lines.

Help,
Dick

-- Richard Webb
Raleigh, NC
Farr and Webb Family Genealogy site: http://Genequake.com/Genealogy
Family and Seismol= ogy site: http://G= enequake.com

___________________________________________________= _______

Public Seismic Network Mailing List (PSN-L)

To leave = this list email PSN-L-REQUEST@............... with the body of the message (first line only): unsubscribe
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Subject: Re: Drop Outs From: Larry Cochrane lcochrane@.............. Date: Mon, 24 Aug 2009 18:02:59 -0700 Hi Dick, Adding more RAM memory may help. It fixed Brett Nordgren's problem he report the other day. Regards, Larry Cochrane Webtronics Richard Webb wrote: > Hi, > Need some advice. I am using larry's ATD board ver 1.4 with the latest > version of WINSDR on a gateway P5-2000 (1997 vintage) with Win 2000, > 256 memory and a 160 GB HD. I have also observed the following with a > Dell Latitude laptop running XP with significantly more memory and > processor speed. > > The trace moves along the screen displaying properly for a few minutes, > all of the lines disappear and then reappear, except that the recent > portion of the trace is a straight green line. The trace continues to > display properly. The result is a series of green lines and traces. > The length of the green line, which is dead straight, can vary from a > minute or two to tens of minutes. It happens on all channels > simultaneously. > > I have removed all other programs, stopped all updating programs and > even tried to use a thumb drive for storage. No effect except that the > thumb seemed to have more green lines. > > Help, > Dick > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Drop Outs From: "Geoffrey" gmvoeth@........... Date: Mon, 24 Aug 2009 18:38:51 -0700 Although I do not know the details of exactly what you are doing I will say that I use only DOS systems to record since windows is a time share kind of thing that never fully relenquishes control to the owner of the machine. If somehow you can give real time priority to your record program then there should be no interruptions of any kind excepting power losses or equipment failure or human tampering. Dos is the only thing I know that gives you maximum control of your own machine. Unless you do your own assembly programming. ( very difficult to master since you need all your hardware register maps and the manufacturers are not cooperating to give technical information) Regards geoff ----- Original Message ----- From: "Richard Webb" To: Sent: Sunday, August 23, 2009 11:18 AM Subject: Drop Outs Hi, Need some advice. I am using larry's ATD board ver 1.4 with the latest version of WINSDR on a gateway P5-2000 (1997 vintage) with Win 2000, 256 memory and a 160 GB HD. I have also observed the following with a Dell Latitude laptop running XP with significantly more memory and processor speed. The trace moves along the screen displaying properly for a few minutes, all of the lines disappear and then reappear, except that the recent portion of the trace is a straight green line. The trace continues to display properly. The result is a series of green lines and traces. The length of the green line, which is dead straight, can vary from a minute or two to tens of minutes. It happens on all channels simultaneously. I have removed all other programs, stopped all updating programs and even tried to use a thumb drive for storage. No effect except that the thumb seemed to have more green lines. Help, Dick -- Richard Webb Raleigh, NC Farr and Webb Family Genealogy site: http://Genequake.com/Genealogy Family and Seismology site: http://Genequake.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Drop Outs From: Brett Nordgren brett3nt@............. Date: Tue, 25 Aug 2009 11:12:43 -0400 Hi Larry and Dick, Adding more memory did help significantly after I went from 500MB to 1500MB. My own problem seems to relate to the fact that the screen represented 24 hours of data at 200 samples per second. That is 17.28 million samples x the number of bytes stored per sample. The dropouts still happen, but not nearly so often now. Since then I have been doing some more checking with the Performance Monitor (XP) and have a couple of observations. For me, dropouts mostly happen when redisplaying the screen (F8), not so often when the screen redraws itself at the end of the line, nor when generating the gif's. Although virtual memory reads and writes go up a lot during a redisplay, so far I haven't found any indication that memory is causing a big problem. At times the swapping rates to virtual memory get quite high, but as far as I can tell the machine appears to be handling it. However..... During redisplay, the processor usage goes solidly to 100%. I am wondering how much processor effort it takes to filter 17 million data points? I had the feeling that the problem was in some way related to filtering, but I never could really see what the relationship was. I am pretty sure that when filtering is turned off the redisplay dropouts disappear. I'll try to confirm that. Hope there is something useful here. Brett At 06:02 PM 8/24/2009 -0700, you wrote: >Hi Dick, > >Adding more RAM memory may help. It fixed Brett Nordgren's problem he >report the other day. > >Regards, >Larry Cochrane >Webtronics Watch our wiggles http://bnordgren.org/seismo/gif_images.htm or watch some very very good wiggles http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Drop Outs From: "Geoffrey" gmvoeth@........... Date: Tue, 25 Aug 2009 09:31:39 -0700 "I have never been able to get consistent results from any Microsoft Windows Operating System. And, error reporting is horrible. And, Windows is not yet user friendly even tho it is the most user friendly one out there today. If you want to have some control MSDOS is the only way for the poor man." You can quote me there, anytime, any place. signed; Geoffrey Morgan Voeth 2009AUG25 0930 MST ROFL ----- Original Message ----- From: "Brett Nordgren" To: Sent: Tuesday, August 25, 2009 8:12 AM Subject: Re: Drop Outs Hi Larry and Dick, Adding more memory did help significantly after I went from 500MB to 1500MB. My own problem seems to relate to the fact that the screen represented 24 hours of data at 200 samples per second. That is 17.28 million samples x the number of bytes stored per sample. The dropouts still happen, but not nearly so often now. Since then I have been doing some more checking with the Performance Monitor (XP) and have a couple of observations. For me, dropouts mostly happen when redisplaying the screen (F8), not so often when the screen redraws itself at the end of the line, nor when generating the gif's. Although virtual memory reads and writes go up a lot during a redisplay, so far I haven't found any indication that memory is causing a big problem. At times the swapping rates to virtual memory get quite high, but as far as I can tell the machine appears to be handling it. However..... During redisplay, the processor usage goes solidly to 100%. I am wondering how much processor effort it takes to filter 17 million data points? I had the feeling that the problem was in some way related to filtering, but I never could really see what the relationship was. I am pretty sure that when filtering is turned off the redisplay dropouts disappear. I'll try to confirm that. Hope there is something useful here. Brett At 06:02 PM 8/24/2009 -0700, you wrote: >Hi Dick, > >Adding more RAM memory may help. It fixed