Yes, the older cesiums (5061, 5040, etc.) had an analog adjustment for the C-Field, which could push the frequency by a few parts in 10^10.
The modern cesiums (5071, 4040, 4310, etc.) automatically servo the C-Field to the atomic spectrum with high accuracy. They can be digitally tuned via RS232 commands with typical resolution of 1e-15. -RL p.s. I don't know how y'all are adding up the Time-Nuts and clocks represented at PTTI but I was there and I have a hundred or so cesiums and a few thousand rubidiums. :-) ----- Original Message ----- From: "Bill Hawkins" <[EMAIL PROTECTED]> To: "'Discussion of precise time and frequency measurement'" <time-nuts@febo.com> Sent: Saturday, December 09, 2006 11:11 AM Subject: Re: [time-nuts] Time Nuts at PTTI this past week > Ah, yes, the C field. A change in magnetic field can change > the clock frequency. Parts in 1e-14 are exceedingly small. > > Is it necessary to correct for the Earth's magnetic field > when the clock travels? > > Bill Hawkins > > Actually, that's a test that can be done at home with a > couple of 2-3 foot diameter solenoid coils. Be tough to > find an ammeter good to 1e-15, though. > > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
