[time-nuts] OT: xtal osc PN

John Miles jmiles at pop.net
Sat Sep 18 13:45:56 UTC 2010

> I just recalled, you do want to check out John Miles (KE5FX) GPIB
> toolkit, the PN.EXE software will let you use your spectrum analyzer (if
> supported) to measure phase-noise. For your purpose it should be useful
> for you. For some of my phase-noise needs my tools isn't sufficient yeat
> to do some of the phase-noise measurements I want.
> John's home:
> http://www.thegleam.com/ke5fx/
> John's GPIB toolkit:
> http://www.thegleam.com/ke5fx/gpib/readme.htm
> John's TimeLab:
> http://www.thegleam.com/ke5fx/timelab/readme.htm
> I was able to contribute support for my spectrum analyzer with some good
> help from John. Happy to see it being part of the distribution now.

Thanks for the plug!  The readme for the spectrum-analyzer utility is
actually at http://www.ke5fx.com/gpib/pn.htm -- TimeLab (nee' TI.EXE) only
talks to counters and ADCs, not SAs.  It is also a very unfinished piece of
work, to put it kindly.

The PN utility in conjunction with a homebrew quadrature PLL is probably
going to be the best way to measure crystal oscillators at this point.
You'll need to build two oscillators to measure against each other.  The
cleaner they are, the more care will need to be taken in the design of the
quadrature PLL.  This technique can give an excellent measurement floor but
it does require you to put in some sweat equity.  The software is the easy
part of the overall problem.

-- john, KE5FX

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