Matthias, You said that the LPRO has a pulling range of 4 PPM. Really? I would think that 4PPB would be much more likely for a Rb.
Dana On Mon, Mar 2, 2020 at 3:21 PM Matthias Welwarsky <time-n...@welwarsky.de> wrote: > 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 -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and > follow > > the instructions there. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
