More precisely, if I had two black boxes, one containing a GPS-Rb-XTAL setup and another containing GPS-XTAL, what measurement would you make from outside the boxes to distinguish from one another?
Antonio I8IOV > Tom Duckworth wrote: > > > Antonio, > > > > Absolutely! With a good XTAL you have parts in the 9th, short term. With a > > XTAL controlled by a Rubidium, in the phase-lock feedback loop, you have > > parts in the 12th, short term. With the Rubidium disciplined by the GPS, > > with its on-board Rubidium/Cesium oscillators updated from the ground every > > orbit, you have parts in the 14th, short term. In other words, your > > XTAL/Rubidium/GPS has an effective short-term Allen variance equivalent to a > > good Cesium; and better than a single Cesium, long term, for a lot less > > money! > > You didn't mention the case of GPS disciplined XTAL. As far as I understand > (unless I'm missing something), the Allan variance in the two cases > (GPS-Rb-XTAL and GPS-XTAL) would be similar. Isn't it? > > The holdover (as answered by David) is another issue, and I was not referring > to it with my question. > > Thanks, > Antonio I8IOV > > > > _______________________________________________ > 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.
