Hi
> On Jan 7, 2018, at 10:21 AM, Jerry Hancock <[email protected]> wrote: > > I’m being a little lazy as I can check the schematics, but in the general > case, do HP counters, frequency generators, etc, switch to the external > reference when one is available or discipline the internal oscillator? No, not if you are talking about the internal OCXO or TCXO. > Are there brands of test equipment that generally discipline vs switch? Not that I’ve seen. The typical approach is to run a VHF oscillator and lock it to either the internal oscillator or to the external reference input. > > Third question, again generally, when you discipline an oscillator, what > impact does this have on the oscillator's phase noise? I assume this third > question depends on the discipline loop (if I’m using the correct term). Yes. It also depends on how noisy the reference to the disciplining loop is. The most common case is that the reference is noisy at short tau. There is a tradeoff made in terms of how much noise is introduced vs how well things are disciplined. Bob > > Thanks > _______________________________________________ > 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.
