Glenn, >From my experience, most precision 10 MHz OCXOs should be settable to within 5 ppb. If settability is not specified, it can be estimated from the tune range and the number of turns of the adjusting device. A rule of thumb is to use one point of resolution for every three degrees of rotation. The 10811 has +/- 10 Hz minimum - assuming they threw in some margin - 30 Hz total range with 18 turns gives 1.4 ppb - you're doing quite well with 0.25 ppb. But, of course the OCXO is probably aging 0.5 ppb/day........... 73, Bob
On Fri, Nov 13, 2009 at 12:59 AM, Glenn Little WB4UIV < [email protected]> wrote: > I just got a system that allows me to compare the phase difference between > a reference and an external oscillator. > I am using a Vectron oscillator installed in a HP 5345A counter as the > external oscillator and a PTB-100 as the reference. > How close to the reference should I be able to set the OCXO? > After a 3 day warm up, it appears that I have gotten the OCXO to within > 0.0025 Hz of the Rubidium reference. > I am checking with a strip chart recorder over a three hour period for the > next few days to see if the OCXO stays at this accuracy. > Is it really possible to set an OCXO this close or have I made some errors > in my computation of frequency offset? > > 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.
