WWVB not WWV. IMO, WWVB is MUCH fussier than LORAN. It's just utter stupidity that LORAN is being shut down.
-John ============ > You will need a receiver to compare your references to. It appears that > LORAN will be shut off, so that leaves two services available, either > WWV 60 Khz or GPS. I do not use WWV any more, I can tell you about GPS. > > To compare against GPS you will need a timing receiver, there are > several available. A lot of us got Motorola Oncore VPs, UTs, or M12+, > The Rockwell Jupiter is one and there are several more. They provide a > 1 PPS signal that is locked to the on board standards on the GPS > satellite. You put this signal in one input of a time interval > counter. You use a 1 PPS divider on your local reference and put its > signal in the other input of the time interval counter. You can record > continuous or take daily 24 hour readings and derive your drift rates. > > GPS corrections are published at NIST; > http://tf.nist.gov/service/gpstrace.htm > > You can also compare against a GPS disciplined oscillator. In the long > term it should be dead on, you will have to have it characterized for > the short term. The HP Z3801A was on the surplus market several years > back, its probably one of the best. The Trimble Thunderbolts were > available to the group a while back. > > Brian KD4FM > > Glenn Little WB4UIV wrote: >> While I was in the US Navy we had two Cesium standards for the >> navigation center on SSBN submarines. >> While in port, we would track LORAN C and compute the drift rate of >> the two cesium standards. >> Is there a service, that has drift rates published, that I can compare >> my standards to, so that I can determine the standard drift rate. >> I do not remember the drift rates that we determined on the submarine, >> that was a few years ago, but, I seem to remember that the rate was in >> the low nanoseconds. >> If a rubidium standard drifts in one direction (does it?) a drift rate >> could be calculated and, after a comparison to a known standard, with >> known drift rate, a very accurate standard could be had for the lab. >> >> What would I expect the drift rate, or jitter, to be in a FRK class >> rubidium oscillator? >> >> Is the drift rate constant enough that a drift rate could be applied >> to a rubidium oscillator to determine it's real frequency at any given >> time. >> >> We calibrated the submarine Cesium standards every three months. >> We had to know the drift rate of our standard as well as the drift >> rate of the standard in each of the LORAN stations to be able to do >> the type of LORAN navigation that we did. >> >> I would like to be able to verify that my PTB-100 rubidium oscillator >> is on frequency. >> >> If I compare two rubidium oscillators, what would I expect the >> relative drift rate to be? >> >> Thanks >> 73 >> Glenn >> WB4UIV >> >> >> >> >> _______________________________________________ >> 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. >> > > _______________________________________________ > 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. > > _______________________________________________ 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.
