[time-nuts] Designing and building an OCXO and GPSDO

[Bruce Griffiths]

Luis Cupido wrote:
> Bruce,
> John,
> ...
>
> And at smaller offsets like 100Hz and less ?
> Shouldn't the improvement be even bigger ?
> Closer to the carrier we are dealing with bigger signals
> so the ADC issues like resolution should be less important,
> and the limiting factor should really be the the
> phase noise of the LO's and etc.
> Am I right ?
>
>
> Luis Cupido.
> ct1dmk.
>   
Luis

The R&S FSU67 has a phase noise of around -104dBc/Hz at 100Hz offset 
with a 640MHz input
The R&S FMU36 has phase noise of around -115dBc/Hz at 100Hz offset with 
a 10MHz input.

The limiting factor at low offsets is almost certainly due to local 
oscillator phase noise.

Bruce