[time-nuts] Proton Precession Magnetometer

John Miles jmiles at pop.net
Wed Apr 6 02:36:29 UTC 2011


> Hi,
> I am boxing up my LPRO rubidium source in a steel box. The device is
> to be thermostated
> by controlling a small fan outside the box to keep the LPRO at about
> 40*C.
> Although the unit is in a mumetal box I assume there may be some
> penetration of earths magnetic field.
> The steel box should help that.
> To test this I want to build a very stable magnetometer. Now I know
> that all you need is a jar of water or kerosene
> to give you protons, and a coil around the jar to kick the protons
> and then listen to them sing.
> I have also been told that these instruments do not work in a
> laboratory, as the AC magnetic field
> drives them crazy.
> I am thinking of lock in amplifiers and phase locked loops.
> Also toroidal coil or paired coils.
> Can anyone in this group point me to an easy to construct and
> fiercely accurate design to build?

Check out Joe Geller's work ( http://www.gellerlabs.com/index.html ) and
also Jim Koehler's (
http://www.geotech1.com/cgi-bin/pages/common/index.pl?page=mag&file=/info/ko
ehler/index.dat&zoom ).  The May 2007 issue of Circuit Cellar had a shorter
article by Jim.

-- john, KE5FX




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