To me, the interesting part is that both the Thunderbolt and the Miller designs appear to degrade the performance of the OCXO in locked mode at short Tau compared to unlocked. The Z3801 does very well < 300sec, but degrades the ADEV at Tau farther out. The Fury does best, never worse locked than unlocked. The practical difference between the Fury and Z3801 at short Tau looks to be mostly in the OCXO, the Fury is the one that actually has the least degradation of the OCXO performance overall.
Performance at short Tau cannot be better locked than unlocked, so it is driven by the OCXO and software, but the fact that two designs (we will forgive the Miller design, which looks to be mated to a very good OCXO, but the Thunderbolt is less excusable) actually degrade the ADEV at short Tau is surprising to me. Didier KO4BB > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brian Kirby > Sent: Tuesday, February 12, 2008 6:57 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] GPS Locked and Unlocked Performance > Comparison > > Its interesting that the Miller/Jupiter design appears to > outperform everything except the Z3801, in the GPS locked > modes. Maybe the KISS principle at work. > > [EMAIL PROTECTED] wrote: > > Hello Tom, > > > > excellent web-page! That looks like a lot of work was done. > > > > Would you have data for 24 hour hold-over performance > (86400s ADEV) > > for these units? > > > > thanks, > > bye, > > Said > > > > > > In a message dated 2/11/2008 21:17:49 Pacific Standard Time, > > [EMAIL PROTECTED] writes: > > > > Sifting through old data, in addition to recent > measurements made in > > the past few months, I have 4 very interesting plots of GPSDO > > performance. > > > > The goal was to see real-life plots of disciplining in action by > > contrasting free (unlocked) vs. GPS-locked performance as compared > > with my 10 MHz house reference. The four GPSDO measured so > far are: > > Z3801A, Fury, Thunderbolt, and Miller. > > > > http://www.leapsecond.com/pages/gpsdo/ > > > > Comments & questions welcome. > > > > I hope to measure quite a few more this year. Contact me > offline if > > you want your favorite one included in the list. Note that I'm not > > necessarily looking for the best GPSDO; instead, for this page at > > least, the more variety the better. > > > > /tvb > > > > > > _______________________________________________ > > 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. > > > > > > > > > > > > **************The year's hottest artists on the red carpet > at the Grammy > > Awards. Go to AOL Music. > > (http://music.aol.com/grammys?NCID=aolcmp00300000002565) > > _______________________________________________ > > 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. > > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.516 / Virus Database: 269.20.4/1275 - Release > Date: 2/12/2008 3:20 PM > > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.4/1275 - Release Date: 2/12/2008 3:20 PM _______________________________________________ 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.
