[Elecraft] P3 as a phase noise measurement tool

[Wes]

Sure, but how do you quantify the "relatively pure" source if you build one?  
Typically you want it to be 10 dB better than what you are measuring (or the 
measuring instrument).

The other option is a commercial source with published specs.  For example I 
have an ebay special Morion MV89 10 MHz OCXO that is specified at -150 dBc/Hz at 
1 kHz offset, which is way better than you could measure with a spectrum 
analyzer technique.

Wes  N7WS



On 6/7/2022 2:12 PM, jerry wrote:
> On 2022-06-07 13:56, Wes wrote:
>  *plus* the phase
>> fluctuations in the measurement system's oscillators and/or sampling
>> clock jitter.  This is the K3/P3.
>
> *** I wonder if the noise of the K3/P3 could be measured using a relatively pure
> signal source - then once that's known, you would subtract the K3/P3's noise 
> from the
> total noise measured from the DUT.
>
>    I had a book somewhere with plans for a really clean single-frequency 
> signal source.  It used several
> identical crystals;  one as an oscillator and then some more as a filter to 
> clean it up.
>
>                   - Jerry KF6VB