Photos of Other PSN Stations

Last Updated: 06/06/2002

Pearland, Texas, USA

Operator: John Cole

Photos of John's sensor can be found here.


Kailua-Kona Hawaii Station

Operator: Tony Potenzo (quakekona@yahoo.com)
Station ID: KO1, KO2 and KO3

Photos of Tony's sensors can be found here.


Western Australia Station

Operator: Arie Verveer (ajbv@iinet.net.au)
Station ID: AU1, AU2, AU3 and AU4

Photos can be found on Arie's Home Page


Buda Texas Station

Operator: Charlie Thompson (ct@onr.com)
Station ID: BUE

The following are links to Charlie's Home Page.

Side View and Top View of Charlie's Lehman sensor.


Corinth Mississippi Station

Operator: Bryan Goss (bgoss@freedom2000net.com)

Photos can be found on Bryan's Home Page


San Francisco California Station

Operator: Phil Giannini (pgianni@hooked.net)
Station ID: SFN and SFZ

The sensor on the right is a 3 sec. vertical with electronic period lengthening and magnetic repulsion. The feedback coil is hidden from view by the repelling magnets. I've been trying to increase the time period of the unit, but as of yet I haven't been able to increase the period much beyond 3 seconds without it starting to oscillate. (natural period of about 1.5 sec.)

To the left is my version of a Lehman sensor with about a 10 second period. Kind-a hidden way in the back of the sensor is a little tub of power steering fluid for the dampening. I used a couple of flywheels from a tape machine for the mass. I plan to replace the guitar string and turnbuckle with a solid rod and a couple of needle valve type adjusters so that it is suspended on the needle points for the pivoting point. The reason for the modification is to try to stop the vertical oscillation around 4.5 hz that I am getting with the present setup. After the modification I plan to turn it more to the west to align it with true north and maybe increase the period as well.

Other modifications to the home-made sensors will include rolling off a little bit more of the high frequencies, as I still am bothered by bus and truck noise from a busy street near me. I find that the street noise is in the 10 hz and up range, and that even the close quakes seem to peter-out above about 8 hz. Currently I am starting to roll off at about 8 hz and am down about 30 db at about 12 hz, so I think I can slide the response down about another 1 or 2 hz.

Lastly way back in the left corner is a plate with three strong motion accelerometer type sensors attached. These are hooked to a Kinemetrics SSA-2 recorder. I also have two of the sensors connected to the SDR recorder through a little preamp that is also mounted on the plate. Not shown is a similar SSA-2 system rigged up in my hanger at the Oakland airport. Each week I down load the data stored in the recorder and compare it with the USGS lists.


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Larry Cochrane - www.seismicnet.com/contact.html