[time-nuts] OXCO Spurious Output at Line Frequencies

Bob Camp kb8tq at n1k.org
Tue Jul 12 17:53:44 EDT 2016


The “practical” solution often is to ship it to an office of the same company that happens
to have 60 Hz power. The spur moves to 60 / 120 / 180 and they move on with their

I have also played the “let’s do it with batteries" approach. Screen rooms were of little benefit.
Simply running test gear on batteries did not do the job. Ultimately we wound up in the 
middle of an Illinois corn field with a bunch of gear modified to run purely on batteries. The
spur did go down, but it never fully went away.  It’s been 40 years since that adventure so I 
really could not say just how far down we got it …. 

Anything past -120 db at line frequency is in the “don’t bother” category. 


> On Jul 12, 2016, at 6:44 AM, Martyn Smith <martyn at ptsyst.com> 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 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

More information about the time-nuts mailing list