[time-nuts] Help with Novatel OEM6 external oscillator

[Attila Kinali]

On Sat, 26 Jan 2019 00:32:46 +0100
Magnus Danielson <magnus at rubidium.se> wrote:

> > Sounds easy. But, Novatel has four fixed (TCXO, OCXO, rubidium,
> > cesium) plus a USER specifications to model the external clock
> > performance.  Each model specifies three coefficients of the power law
> > spectral density (h-2, h-1, h0).  If you google 'novatel
> > externalclock' you can see the command. My question is, how do I
> > translate an oscillator ADEV plot into the three coefficients?
> 
> First of all, an excellent question!
> 
> > I'm not an oscillator noise guru by any means (in fact, I'm probably a
> > noise dummy).  It took me a while to figure out that the number range
> > that Novatel is looking for is Allen Variance.  So taking the square
> > root of their model numbers would be Allen Deviation (hope this is
> > correct).
> 
> Actually, these numbers is really power-levels for the various noise-types.

[... big explenation snipped ...]

Enrico Rubiola's Noise chart comes handy in these kind of calulations:
http://rubiola.org/pdf-static/Enrico's-chart-EFTS.pdf

			Attila Kinali

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