[time-nuts] Spec An for phase noise measurements

[Matt Ettus]

> I am seeing the following performance when measuring the built in 30
> MHz reference:
> 100 Hz     -81dBc
> 1 kHz        -108 to -110
> 10 kHz      -117
> 100 kHz     -125
> 1 MHz        -131
>
> All of those are 3-8dB better than the spec, except for at 1 MHz where
> the spec is -135.  The measurements do jump around a bit.

If I change to "Digital mode for <100 Hz RBW", and turn on averaging,
I get much better results from the analyzer --

100 Hz    -100dBc
1 kHz       -110
10kHz     -120
100kHz    -129
1M            -135

This, of course, makes me question all the measurements....

Matt