Hi Hal, On 04/04/2016 05:39 AM, Hal Murray wrote:
Has anybody studied what happens when a GPSDO comes out of holdover? Has anybody seen any specs? I don't think I have. I think you have a choice of quick recovery for time or frequency, but you can't get both. Suppose your setup has been in holdover for a while. The frequency is slightly off. The time offset of the PPS pulse will be the integral of the frequency offset. What happens when you come out of holdover? If you fix the frequency, the PPS will stay off. Suppose the PPS has drifted by 1 ns. If you correct that in 1 second, the frequency will need to be off by 1E9 during that second.
The RAI laboratory in Torino have made such tests and published measurements and recommendations. For a long time it was only available in italian, but there is now an english version available.
Cheers, Magnus _______________________________________________ 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.
