On Sat, Jul 5, 2014 at 10:47 PM, Bob Stewart <b...@evoria.net> wrote:
> First, an apology. When I changed the topic on my original post, I > thought that would be OK. Apparently that's still a thread-jacking. Sorry. > > I'm still interested in this Magnetic Resonance Spectrometer thing, > though. On page 335 of the pdf linked below by Dave, there's an experiment > with an MRS using water and the magnet from a magnetron available back > then. Apparently the resonant frequency of hydrogen nuclei in water is > 6.131325 MHz in that magnetic field. Did anyone ever pursue this with the > idea of creating a frequency standard, or was the technology just too > primitive at the time? Perhaps it's a repeatability problem from the > magnetic flux standpoint? I can guess that temperature changes would cause > enough of a flux strength change to cause a problem, but that's just a > guess. > The substance recommended was Ferric Chloride as I recall. The characteristic was that the peak occurred quickly even with the rapid change in the B-field. The B-field was modulated at a 60Hz rate, enough to sweep the resonance across the oscillator's frequency. When the nuclei precessed at the frequency of the oscillator, the nuclei would absorb power from the oscillator, changing the plate-current of the oscillator. It was really just a fast grid-dip oscillator. (Well, plate dip oscillator.) Pretty simple. I keep threatening to build a new one that works much better and has a wider range, just to prove that I can. :-) And I can't think of any way of tying this to time-nuttery. If there are others still interested in this topic perhaps we can just communicate off-channel. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.