On Wed, 15 Jun 2016 18:43:38 -0400 Bob Camp <kb...@n1k.org> wrote: > > Same as above. > > If you lock the VCXO to an OCXO, this will be much better. > > Each time you steer the OCXO to lock things up, you will degrade both it’s > ADEV and it’s > phase noise. If the GPS drops out when you do this …. the GPSDO never locks > up.
Yes, sure. The ADEV of an OCXO will turn upwards again at taus somehwere around 10 to 1000 seconds. The loop bandwidth of the PLL that locks the OCXO to GPS should be in the same range in order not to degrade the short term stability of the OCXO. Also the PLL should have a rather damped behaviour in order to average out the "phase jumps" resulting from the jitter of the GPS PPS. If these two points are not taken care of, then yes, the ADEV, resp the phase stability will degrate and thus can cause the GPS receiver to lose track of the satellites. Attila Kinali -- Malek's Law: Any simple idea will be worded in the most complicated way. _______________________________________________ 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.