once again, a simple experiment would suffice. Got a refrigerator magnet handy? Don
Lux, Jim (337C) >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of Rick Karlquist >> Sent: Thursday, August 13, 2009 3:35 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] OCXO sensitive to gravity >> >> Tom Duckworth wrote: >> > The orientation change is due more to the earth's magnetic flux >> effect on >> > the oscillator, and less so from gravity. >> > >> > Tom >> > Tom Duckworth >> > [email protected] >> >> Sorry, this is simply incorrect. Magnetic flux from the >> earth has no effect on quartz oscillators. There is no >> mechanism there. Acceleration definitely affects quartz. >> >> > > Hmm. We're investigating just this at work, in connection with things > destined to orbit Jupiter, where we expect to see a periodically varying > flux as the spacecraft spins. The quartz is insensitive, but the mounting > isn't necessarily insensitive to magnetic fields, especially if any > magnetic materials (i.e. Kovar seems to be of interest) are used. > > If you have any circuits sensitive to DC offsets, then a varying magnetic > field can cause problems (e.g. the VCO input in a PLL). > > I suppose it depends on "how good" the oscillator is expected to be... > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
