[time-nuts] 10MHz Rubidium reference source for frequency counter

[Karen Tadevosyan]

John,
Thank you for the links (I visited few times before) and your recommendations. 
Really I am looking for a source with a good short range stability performance between 1 and 10 seconds. 
I will prepare additional description of my task with more details shortly ...
Special Thanks for your TimeLab software which I use for ADEV and  PN measurements.
Karen, ra3apw

> Date: Sun, 26 Oct 2014 14:28:24 -0700
> From: "John Miles" <john at miles.io>
> 
> > Can I have your recommendation regarding a choice of 10 MHz rubidium
> > source (available now on eBay like FE-5680; LPRO-101; LPFRS; FRS etc.)
> > as a reference signal for my frequency counter Pendulum CNT-91.
> >
> 
> You might take a look at the plots at http://www.ke5fx.com/rb.htm if you
> haven't already, and also at http://febo.com/pages/oscillators/rubes/ .
> These will give you an idea what to expect from some of the popular Rb
> models.  The PRS10 mentioned by Said is a great choice for long-term
> measurements, but it's also the most expensive of the ones you are likely to
> find on the surplus market.
> 
> Interestingly, if you want the best performance between 1 and 10 seconds
> the PRS10 is actually the worst of the ones I measured.  But the CNT-91
> probably will not be able to see the difference, since its single-shot
> resolution is a bit worse than the HP 5370B counter (see attached plot).
> 
> Caveats: 1) No rubidium standard will give its best long-term performance
> until it has been allowed to run undisturbed for at least a few days.  2) These
> plots shouldn't be taken too seriously because of the (very) small number of
> examples tested under inconsistent environmental conditions.
> 
> -- john, KE5FX
> Miles Design LLC