PSN-L Email List Message

Subject: RE: noise
From: Bob Hancock Bob.Hancock@............
Date: Sun, 03 Apr 2005 15:50:22 -0700

Bryan - 

Not sure where you are located, but the microseisms are high right now.  You
can check out a Navy web site that shows ocean wave height around the world,
from current, to projected wave height for 144 hours in the future.  Ocean
waves are a big contributor to seismic noise in the 6 to 10 second period
noise.  The link to web site is

More information can be found with the ALBUQUERQUE SEISMOLOGICAL LABORATORY
This can be downloaded from the following link

Another quick reference for microseisms is the Lamont-Daugherty Cooperative
Seismic Network (LCSN), near New York City.  Their link is

Hopefully these links will help you in making determinations of your seismic
activity.  As you can see the microseisms are high on the LCSN web site, and
I am experiencing high microseisms at my location, about 30 miles west of
Tucson, Arizona.

Bob Hancock
Tucson, AZ

-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of 1goss@...........
Sent: Sunday, April 03, 2005 15:02
To: psn-l@..............
Subject: Re: noise

I am having problems with noise during the night. Oddly it starts about
9:00pm and ends about 11:00 am.

9:00pm WinSDR screenshot

11:00am WinSDR screenshot

I think these pictures will explain much more than I can.

I thought it could be because the shop has a concrete floor and the air in
the shop heats up to aournd 70F during the day and cools to around 36F at
night. I believe the slower cooling of the floor during the night could be
causing  convection in the box. I tried to seal the box off and covered it
with a blanket but that did not work. Could it be caused by the temperature
change in the mineral oil and the vertical dampener?

I ran FFT but to be honest, I'm not sure how to read it.

Thank you for any help you can offer.

Bryan S. Goss


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