On Tue, 14 Mar 2017 21:25:19 -0700 Chris Albertson <albertson.ch...@gmail.com> wrote:
> You can also verify the GPSDO is working correctly by looking at the > EFC voltage. That is the control signal the controller sends to that > $25 eBay crystal. You'd expect that the ESFC volts follows some kind > of theory and tracks the environment and you'd not expect a random This depends very much on the oscillator used. If it's a good OCXO, you will see hardly any influence from environment and the EFC will be dominated by GPS noise at short time scales and aging of the OCXO at long time scales. Have a look at what TvB reported in November[1,2] on the measurement of a bunch of Thunderbolts(free running). Yes, there is something that seems to be environmental effects for some oscillators at some time scales. Figuring out where you actually see such effects will need some serious statistical skills. IMHO it's much easier to just get a known-good GPSDO and a rubidium for verification. Attila Kinali [1] https://www.febo.com/pipermail/time-nuts/2016-November/101913.html [2] https://www.febo.com/pipermail/time-nuts/2016-November/101939.html -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor _______________________________________________ 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.