[rescue] Oh no! This poor Origin server.....
mcguire at neurotica.com
Thu Apr 1 21:43:36 CST 2004
On Apr 1, 2004, at 10:19 PM, Joshua Boyd wrote:
>>>> because I have an interest in proton-precession magnetometry and
>>>> gradiometry. Someday I hope to have that much free time.
>>> I, in my insignificance, bow before the radiance of your magnificent
>>> |bergeekdom. :) I wouldn't know a proton-precession magnetometer if
>>> it leaped out from behind a field of monopoles and bit me in the ass.
>> Uhh, what?
>> Dude, they are *really* simple. You could build one in an evening.
Uhh, I'm not going to type up huge amounts of detail, but here's the
Go to Home Depot (or equiv.) and get a 9-12" section of 3 or 4"
diameter PVC pipe and some end caps. Fasten one end, fill it with
kerosene, then fasten the other end. Be sure to get a good seal. Wrap
a few dozen turns of fairly thick (~14ga) wire around it.
Build an amplifier and a bandpass filter centered around 2.46KHz.
Get a large-ish 12V battery (like a lantern battery) and a beefy DPDT
toggle switch. Wire up the bandpass filter/amp combo, the coil around
the kerosene cell, and the battery in such a way that the coil can be
alternately switched between the battery and the filter/amp combo.
Connect the output of the amp to a speaker or a set of headphones, as
well as a frequency counter.
Voila. A proton-precession magnetometer.
Of course, myself, I would do it with some big MOSFETs, a
microcontroller (no, not some monster with an MMU and an operating
system, Josh. ;)), and an LCD.
Here are some links:
Dave McGuire "PC users only know two 'solutions'...
Cape Coral, FL reboot and upgrade." -Jonathan Patschke
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