PSN-L Email List Message
Subject: Re: Galitzin-type seismometer
From: John Popelish jpopelish@........
Date: Mon, 31 Oct 2005 21:21:14 -0500
Rick Groleau wrote:
> John Popelish wrote:
>> Rick Groleau wrote:
>>>For anyone who's interested, I've just put together a page of my
>> Mechanically, the design looks very nice. Electronically, it is
>> pretty primitive and simple upgrades could improve it significantly.
>> The coil is unshielded, and the amplifier has no filter function
>> included to reject either 60 cycle hum or other mechanical noise that
>> isn't part of the seismic signal. Still it does pretty well with what
>> it's got.
>> Are you interested in changing anything at this point?
> Thanks for the comments, John. And yes, I wouldn't mind replacing the
> amplifier with something more up-to-date, and with connecting the system
> to my computer (which may be difficult, since I use a Mac). Any suggestions?
I am fascinated with the germanium amplifier and how it might be
simply upgraded. Are you interested in replacing a few components to
get more gain and less noise from it before you replace it? It is a
If so, I would like to know what the collector voltage is with respect
to ground for each stage. I suspect that the choice of bias resistors
is not at all optimum to get the full capability out of these old
The cheapest digitizer I know of to get something into your computer
would be one of the DATAQ units available on this page:
One of these could be hooked up between your present amplifier and the
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