Oops I found more just as you suspected. "Rb RF frequency stability After a minimum of 22 minutes of warm-up at 25° C (77° F), interface circuitry with 0.05-ppm 15-MHz accuracy can be maintained for a minimum of seven years with CTU adjustment of the OM frequency. For temperatures between 0-10° C (32-50° F), a minimum of 26 minutes warm-up is required for frequency stability."
It would appear that the Rb is disciplined if I'm reading the above correctly. 73, Paul On Sun, Dec 12, 2010 at 11:35 PM, Paul Cloud <jpclou...@gmail.com> wrote: > Well I suppose that my use of the word "spec" was incorrect the quote > is listed below. > > "OM redundancy The Oscillator Module provides a highly stable timing reference > capable of being disciplined from an external source, such as the GPS > receiver or network clock. Two versions are available: Rubidium based > (OMR), which is capable of running for 24 hrs without an external > reference (flywheeling), and Quartz Crystal based (OMQ), which can > flywheel for eight hours. The OMR serves as a primary timing > reference where high long term accuracy is required. The OMQ can be > used as a primary source, where long term drift accuracies are more > relaxed or as a secondary (back-up), to be used upon the primary’s > failure. The OMR may also be used as secondary if desired, in > applications where low cost is not a requirement." > > I should also state that this is not from actual documentation for the > unit that I have. But, it is actual documentation for a system later > by some 3 years. > > Thanks and 73, Paul > > > > On Sun, Dec 12, 2010 at 11:00 PM, Hal Murray <hmur...@megapathdsl.net> wrote: >> >>> Are you under the impression that the Rb is disciplined also? I had thought >>> that the GPSDO side was disciplined and the Rb was only for holdover, they >>> seem to call it fly-wheeling. They spec 8 hour holdover for the GPSDO and 24 >>> hour holdover for the Rb in the limited info I've been able to snag. I'm >>> still digging for more info. >> >> Holdover is more than just a single number. >> >> I'd expect something like: >> The PPS will be within X microseconds for Y hours. >> >> It might be that there are two sets of specs, one for a crystal and another >> for a Rb option. I'd expect the Rb option to have smaller X or longer Y. >> >> >> Most Rb units have an adjustment (screwdriver or voltage) to correct for the >> local magnetic field. If you have that sort of adjustment voltage, you can >> easily turn it into a GPSDO. >> >> >> -- >> These are my opinions, not necessarily my employer's. I hate spam. >> >> >> >> >> _______________________________________________ >> 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. >> > _______________________________________________ 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.