[time-nuts] Time-Nutters-- Adding Rubidium to a Thunderbolt...?

[Matthias Welwarsky]

On Montag, 2. März 2020 22:20:48 CET Matthias Welwarsky wrote:
> On Montag, 2. März 2020 18:32:44 CET Skip Withrow wrote:

> 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.

Before anyone gets confused: the MDEV of 1e-14 is _not_ the Rb or the GPSDO 
output. It's the DAC output scaled to 1 LSB (about 60ppq for the LPRO and 16 
bit DAC). It's also frequency, not phase. It doesn't tell anything about the 
GPSDO's system performance, but it allows an insight into the disturbance 
caused by the control loop, for small Tau. For large Tau, it will show the 
oscillator drift against the GNSS reference.

BR,
Matthias