I have a corby ocxo (datum-1111c) that I am coupling with a fury oem board soon (need some connectors). I wish someone with good measurement equipment lived nearby. I would like to measure this vs my standard fury. I think the ocxo is mid 10-13 at 1s. Anybody near Kansas City?
Doc Sent from my iPad On Sep 30, 2012, at 7:02 PM, ewkeh...@aol.com wrote: > Doc > The units I mentioned have been done by Corby, but I let units run two > weeks before I do any test. In the future when I do the 40+ two a week > running > parallel and the best rerun after 4 week soak. > Bert > > > In a message dated 9/30/2012 7:55:43 P.M. Eastern Daylight Time, > docdai...@gmail.com writes: > > Bert, > > When you do tests like this, how long do you let the oscillators "settle" > prior to testing? > > Doc > > Sent from my iPad > > On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: > >> Rick >> I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few > as >> low as 4 E-13 at 10 seconds. How low have you seen, I have the > opportunity >> to test 40+ units and hope to find a few even better ones. Any guidance > will >> be appreciated. >> My best reference is 3 E-13 so any thing as good or better would have to > be >> tested by some one else after initial test. >> Bert Kehren >> . >> >> >> In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, >> rich...@karlquist.com writes: >> >> I only measured one 10811. However, John Vig's tutorial >> (available at IEEE UFFC) rather categorically states that >> piezoelectric resonators have flicker noise of frequency. >> What I measured was most closely related to phase noise, >> as opposed to Allan Deviation. Phase noise of 10811's is >> more consistent unit to unit than ADEV and certain more consistent >> than aging. BTW, ADEV at HP was measured against a >> special 10811 that was 500 Hz off frequency. I was never >> able to find out how they arrived at this "golden" unit. >> But it seems clear that it could not have been the >> best ever unit for ADEV, thus the real "golden" units >> that came down the pike were simply rated as ADEV too good >> to measure. I tried to get a project started where we >> would use a frequency synthesizer to do the offset. >> Then we could take the best units and compared them against >> each other. Then, as well accumulated test data, the >> cream would gradually rise to the top and we would have >> some true golden units. The problem was that there ADEV >> at those levels wasn't a "money spec". >> >> Rick >> >> On 9/30/2012 12:16 PM, Ed Palmer wrote: >>> Would this characteristic be similar across all 10811s or would there > be >>> as much unit to unit variation as there is for aging and Allan > Deviation? >>> >>> Ed >>> >>> On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: >>>> I recently modified an old 10811 to bring out the crystal >>>> leads on miniature coax (instead of having them connect >>>> to the oscillator circuit). This allowed me to measure >>>> the crystal's inherent flicker noise of frequency. >>>> The measurements indicate that the 10811 phase noise out >>>> to at least 100 Hz is entirely due to the crystal. >>>> An interesting aspect of flicker noise of frequency >>>> is that Allan deviation is independent of tau. Thus, >>>> just one number describes the crystal noise. >>>> >>>> Rick >>>> >>>> On 9/30/2012 4:44 AM, Bob Camp wrote: >>>>> Hi >>>>> >>>>> Close in, it looks like it's pretty much the crystal and the loading >>>>> of the bridge oscillator. >>>>> >>>>> Bob >>>>> >>>>> On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist >>>>> <rich...@karlquist.com> wrote: >>>>> >>>>>> The E1938A uses a crystal that is basically the same as >>>>>> the 10811 crystal except that it is in a reduced height >>>>>> package. However the phase noise is not as good as a >>>>>> 10811 due to broadband noise in the automatic frequency >>>>>> control circuit. By the time I discovered this, it >>>>>> was too late to try to fix it. >>>>>> >>>>>> Rick Karlquist N6RK >>>>>> E1938A designer >>> >>> >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. > > _______________________________________________ > 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.