[time-nuts] Frequency Stability of Trimble Mini-T

[John Miles]

> > I can't find much fundamental research on this at all; and if
> even Mr. Vig
> > says the phenomenon is not well understood.. But there are
> (propriatary) ways
> > to  probe for the susceptibility of a particular unit to do this.
>
> John told me once that an easy way to deal with many classes
> of jumps is simply use a pair of OCXO. This is an easy solution
> for a time-nut (driven by interest and passion), perhaps much
> less so for a manufacturer (driven by market and profit).

Hmm, it's worth considering how good the secondary oscillator really needs
to be.  If the jumps tend to occur once per minute in a cheap oscillator and
once per hour in a good one, and if they're truly uncorrelated, then it
might be reasonable to detect jumps in either oscillator by differentiating
the beat note between the cheap and expensive rocks.  A third cheap
oscillator would be used to 'vote' on which one was responsible for the
observed jump.

You would only need oscillators of equal quality if you wanted to improve
ADEV and/or PN performance across the board.  Detecting fast excursions
should in principle be much easier.

-- john, KE5FX