[time-nuts] evaluating an oscillator with the allan deviation

[folkert]

> > Thanks for the raw data. Attached is Folkert-02.png which is the ADEV from
> > column 1 (your function generator vs. Arduino) and column 2 (your Adafruit
> > 1PPS vs. Arduino). In this case it's quite clear that the Arduino crystal
> > is much better than your function generator. In other words, you probably
> > didn't need the Adafruit GPS. But you can't know that until you make the
> > measurement.

> But the function generator, too, is based on an arduino. Maybe one just
> happens to have a better oscillator than the other at that temperature. It
> would be interesting to swap them over and see if the function generator
> improves.

I think I should let them run together during the test, right? Because
of temperature and power fluctuations (the washing machine is unfortunately
situated in my man cave).

  GPS ----+---- comparator1  ---- funcgen1
          |
	  +---- comparator2  ---- funcgen2

I need to solder a buffer for the GPS first.


Folkert van Heusden

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