It would be interesting to switch the A and B oscillators. The 10811 spec can vary widely.
Thomas Knox > Date: Mon, 22 Oct 2012 07:21:08 +1000 > From: [email protected] > To: [email protected] > Subject: [time-nuts] GPSDO three cornered comparisons > > Hi All, > > I have an HP 58503A and a Symmetricom 58503B which are behaving quite > differently to one another using a common antenna. Using Z38xx, there's > almost an order of magnitude difference between the reported ADEVs at > 40k seconds (HP:7e-13, Sym:5e-12). Both have 10811 oscillators and are > reporting similar ADEVs up to about 1000 seconds. The Symmetricom is > also showing large daily temperature variations, while the HP is stable, > noting that ambient is varying 5-10dC over a day (I'll measure this from > now on). > > I connected my modified Tbolt (new/good oscillator removed from PCB, old > temperature sensor chip removed from PCB and bonded to oscillator can), > which is showing performance between the two 58503s, although it's only > been connected for a day (but has been powered for weeks). > > So is my HP 58503A telling me fibs, or is the Symmetricom crook? > > I'd like to do a three cornered hat comparison between them. I'll > collect PPS TI data (A-B, A-T, B-T) using Timelab and a PM6681 (the only > TIC I have), but need help on how to post-process the data sets to > isolate the individual units' performances. > > Any tools out there to help (without purchasing Stable32)? I can use > Perl to manipulate the raw data, but don't have the maths skills to do > the analysis myself. > > Thanks, > > david (still an apprentice TN, but probably addicted already). > > > _______________________________________________ > 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.
