fred jones wrote:
> This is a proton precession magnetometer.

There was a very good article by James Koehler on this topic in
Circuit Cellar #202, May 2007.

   http://www.dtweed.com/circuitcellar/caj00202.htm#3455

He used a LM394 SuperMatch NPN transistor pair as the first two stages of
his amplifier. You should probably look at the rest of his design as well.

-- Dave Tweed

P.S. Seriously, you need to get a new email client. This one is sending out
your messages as one long line of text, broken every 990 characters with a
"!\n" sequence. They're virtually unreadable.
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