Jim, Would an inexpensive Rubidium unit do what you want? I know it won't be closer than a few ppb, but in my experience (LPR101, FE-5650A, FE-5680A) they are stable inside about four minutes. The big advantage is they don't need GPS at all.
Regards, Murray ZL1BPU Message: 1 Date: Wed, 14 Jul 2010 06:42:50 -0700 From: jimlux <jim...@earthlink.net> Subject: [time-nuts] rapid startup GPSDO To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Message-ID: <4c3dbeda.7010...@earthlink.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Is there some (inexpensive) GPSDO that has a "time from power on in an unknown location to reasonably stable" in the <5 minute category? Frequency accuracy in the 1E-9 range would be fine. A regular old GPS has a Time to First Fix well under that, and it should be cranking out 1pps pulses with 1E-7 or 1E-8 precision pretty quickly.. Would it be fair to say that after 100 seconds, one could theoretically have driven that down another factor of 10? As I understand it, a thunderbolt needs some number of hours after turn on to stabilize, but just how bad is it after, say, 5 minutes. _______________________________________________ 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.