[time-nuts] Disciplining Rubidium

[Björn Gabrielsson]

Hi,

On Wed, 2008-04-23 at 20:01 -0700, John Miles wrote:
> Adding to Tom's worthy list:
> 
> 11) Short-term phase noise; the GPS-Rb sources don't seem to be as clean as
> the better GPS-OCXO packages.
> 
> -- john, KE5FX

For the "normal" Rb that seems to be true. But the OP specified the XTAL
in both chains to be compareable.

What are the reasons a Rb with the phycics package diciplining a double
oven XTAL, could not achive a "clean" output?  (ofcause this ads to the
Rb pricetag...)

Concider these two setups

Oncore M12T -- FRS-C -- HP10811 
Oncore M12T -- HP10811    (Typical GPSDO setup)

Why would the first setup have significantly less clean output?

> 
> > > More precisely, if I had two black boxes, one containing
> > > a GPS-Rb-XTAL setup and another containing GPS-XTAL,
> > > what measurement would you make from outside the boxes
> > > to distinguish from one another?
> >
> > Ah, clever question. Here's ten ways to distinguish them...
> >
> 

--

   Björn