Hi I do not know of any commercial GPSDO's that do not have a holdover feature. There are a lot of variables. With a large package OCXO and a couple days operation, the numbers I gave should be good 90 to 99% of the time.(99 seconds out of 100).
If the unit has such a poor antenna location that (unlike the original post) it never completes survey, then all bets are off... The basic assumption is "locked to > 4 sats at all times. That generally translates to 6 or more most of the time. Bob Sent from my iPad > On Aug 20, 2016, at 5:43 AM, Bryan _ <[email protected]> wrote: > > Bob: > With a GPSDO as a general rule is there much variation of the 0.005 to 0.02 > ppb range. Would there me much if only 2 satellites were visible but the unit > was no in holdover vs say 6 satellites. I assume there is probably a lot of > variables such as quality of GPSDO and OCXO, multi path interference, antenna > location, etc, but worse case what would a user expect assuming the unit > isn't in holdover. > > -=Bryan=- > >> From: [email protected] >> Date: Fri, 19 Aug 2016 20:03:59 -0400 >> To: [email protected] >> Subject: Re: [time-nuts] Expected 10 MHz offset from a GPSDO? >> >> Hi >> >> Ok let's toss some numbers into the mix. >> >> The counter time base one day after calibration is in the 0.5 to 1.5 ppb >> range. >> >> The LPRO ten years after it left the factory is in the 0.5 to 1.5 ppb range. >> >> The GPSDO when running properly should be in the 0.005 to 0.02 ppb range at >> one second. >> >> One ppb at 10 MHz is 0.01 Hz. It also is a the resolution limit on a 5335 at >> 1 second. >> >> Bob >> >> >> >>> On Aug 19, 2016, at 5:29 PM, Mark Sims <[email protected]> wrote: >>> >>> Try driving your counter frequency reference input with the LPRO or >>> comparing the LPRO with the GPSDO. The LPRO is (most likely) much more >>> accurate the counters' internal timebase. >>> _______________________________________________ >>> 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. > > _______________________________________________ > 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.
