[time-nuts] OXCO Spurious Output at Line Frequencies

[Wes]

I retired in 1999 so it's been a long time since I used one, but I don't recall 
ever seeing a device measured using an HP 3048 system that didn't exhibit line 
frequency (and harmonic) spurs.

See the "live" plots at the end of this page: 
http://hpmemoryproject.org/news/3048/hp3048_01.htm

Wes

On 7/12/2016 3:44 AM, Martyn Smith wrote:
> Hello,
>
> I have a customer who is measuring the phase noise of my 10 MHz ultra-low phase noise frequency standard.
>
> He is seeing spurious signals at line frequencies (50 and 100 Hz as we are in Europe) at a level around -130 dBc.
>
> My opinion is that it's impossible to get much better than that.  Even running on batteries make little difference, since the equipment is in a test rack with AC signals everywhere.
>
> Even the £50k R&S test set he is using only quotes a spurious spec of -90 dBc.
>
> What experience does anyone have here?
>
> Best Regards
>
> Martyn