On Montag, 2. März 2020 18:32:44 CET Skip Withrow wrote: [...] > The Thunderbolt DAC steps in 10uV steps IIRC. And it steps its DAC > voltage every second. With GPS signals jumping around you can still > (will) end up with poorer short term performance than if the Rb was > left to its own devices. Hint, let the Thunderbolt do its thing with > the Rb, but use Lady Heather and disable disciplining when making > measurements/comparisons.
The LPRO has a pulling range of just 4ppm at the external C-Field input (0-5V swing). 10µV steps over 6V should be, like 19 bits or so? That should give at least 7e-15 resolution for the DAC. With a reasonably stable PPS from a timing receiver, just looking at the DAC movements, it should not be a problem to have a MDEV of 1e-14'ish for tau=1s. The LPRO itself probably has a MDEV of somewhere between 1e-11 to 1e-10 at tau=1s, so the GPSDO is not going to cause a lot of disturbance. Some, yes. The undisturbed Rb will always be better short-term than the disciplined one. But not an awful lot. BR, Matthias > > Regards, > Skip Withrow > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow > the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
