Greetings all,
My GPSDO prototype (with not just a frequency-locking, but also
phase-locking loop) seems to run reliably now.
But there is one thing which puzzles me, maybe someone here has more
experience with 'commercial' VCOCXOs.
Mine was found at a hamfest, labelled "OFC MC598X4 - 010W 10.000000 MHz"
The tuning range, compared against GPS, is as follows:
Vctrl = 0 V -> output frequency 10 MHz - 57 Hz
Vctrl = 5 V -> output frequency 10 MHz
Vctrl = 12 V -> output frequency 10 MHz + 80 Hz
So the 'electric' tuning range is - 5.7 ppm to + 8 ppm.
Isn't this a bit much for an oscillator labelled "10.000000 MHz" ?
I had expected a tuning range of a few Hz (since the frequency is
specified with 1 Hz resolution on the label).
If anyone is interested in the PIC "C" sourcecode (written for a
PIC16F1783), I can post it on a website as soon as some cosmetic issues
(and curses about the PIC datasheet) have been fixed / removed.
All the best,
Wolf DL4YHF .
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