## PSN-L Email List Message

Subject: Whip antenna
From: tchannel1@............
Date: Sat, 5 Apr 2008 10:01:11 -0600

```Hi Folks, If I had a 36" whip antenna, just a piece of spring steel rod, =
with a small mass on the tip, how much would the tip move during a =
earthquake?
I know that is just a general question, and it would depend on many =
factors.   Let's say the size of the event was 6.0M, 1000 mile away.  =
This event would be recorded by all three of my sensors.  The movement =
of sensor's pendulum or vertical spring during this type of event would =
probably not be noticeable to the eye.  If the event was a large one, =
then surely it would be noticeable to the eye, perhaps even 1/8" or =
more.

I am still trying to come up with a Earthquake Directional Device.   I =
have seen articles on the Chinese versions, and turn of the century =
devices which used a variety of approaches, where a normal pendulum or =
even a  "Wipe Antenna" / inverted pendulum would be set in motion and =
make contact with a circuit.   I know such devices would work in =
California, but I don't know how small or weak events would work. =20

My thinking is, if I just use the motion of a "Whip Antenna" to close a =
contact, it would not record much, unless I could move the two points of =
contact to within the thickness of a human hair.

I know I could use a magnet/coil and the device would work on most all =
earthquakes, presently recordable, but I don't want to dismiss these old =
approaches either.

Just wanted to get an opinion.

Thanks, Ted

Hi Folks, If I had a 36" whip antenna, =
just a piece=20
of spring steel rod, with a small mass on the tip, how much would the =
tip move=20
during a earthquake?
I know that is just a general question, =
and it=20
would depend on many factors.   Let's say the size of the =
event was=20
6.0M, 1000 mile away.  This event would be recorded by all three of =
my=20
sensors.  The movement of sensor's pendulum or vertical spring =
during=20
this type of event would probably not be noticeable to the eye.  If =
the=20
event was a large one, then surely it would be noticeable to the eye, =
perhaps=20
even 1/8" or more.

I am still trying to come up with a =
Earthquake=20
Directional Device.   I have seen articles on the Chinese =
versions,=20
and turn of the century devices which used a variety of approaches, =
where a=20
normal pendulum or even a  "Wipe Antenna" / inverted pendulum =
would be=20
set in motion and make contact with a circuit.   I know such =
devices=20
would work in California, but I don't know how small or weak events =
would=20
work.

My thinking is, if I just use the =
motion of a "Whip=20
Antenna" to close a contact, it would not record much, unless I could =
move the=20
two points of contact to within the thickness of a human =
hair.

I know I could use a magnet/coil and =
the device=20
would work on most all earthquakes, presently recordable, but I don't =
want to=20
dismiss these old approaches either.

Just wanted to get an =
opinion.

Thanks, Ted

```