Ian, you should have time standard frequencies in Australia on 5 10 and 15 
MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the 
output of the 10 MHz timebase in your service monitor.

This has  been one of my obsessions for a while now, to find a way of more 
accurately setting my 10 MHz timebase in my service monitor.

Zero beating with our WWV signal will only get you within a cycle or so. 
(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then 
there's 
trying to find a time when the signal is strong and doesn't fade too much. 
Since I live about 50 miles south of Ft Collins you would think I would have a 
strong signal all the time, but no.

So I figure there must be a way to use a scope to compare two audio signals 
(X/Y like we do with PL tones) and be able to set it more accurately. I have 
tried comparing the 1000 cycle audio tone from an external receiver when I 
generate a signal from the service monitor I kc off frequency from WWV. Then 
comparing that to the 1kc tone generated from the monitors own PL tone 
generator 
(phase locked to the 10 MHz time bases). You should be able to see a slow drift 
between the two on the oscilloscope but so far no success, too much noise to 
see much.

Does someone have a way of getting closer than 1 cycle? (no I haven't bought 
a GPS timebase receiver yet but have drooled over them on Ebay.

I've always wondered if a tuned RF receiver using 10 MHz crystals for IF 
filters would give you a strong 10 MHz carrier that could be used for 
calibration.

Hopefully this is still somewhat on topic since we all need to set our 
repeaters on frequency.

Art - KC7GF
Golden, CO



 

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