IC-7000 Frequency Alignment Question
I noticed that my IC-7000 is slightly off frequency, both receiving WWV
and counting the transmitted signal. Twenty MHz WWV appears to be about
12 Hz high after the radio has warmed up. I realize this isn't much,
but it is outside the radio's 0.5 ppm specification.
The IC-7000's 24.8064 MHz reference oscillator is used to generate the
synthesizer clock as well as the second and third local oscillators. It
does not appear to have a variable capacitor or inductor for its
adjustment. Instead, it is voltage controlled. Apparently the voltage
is adjusted to correct the frequency, and the value is digitized and
stored in non-volatile memory.
The service manual provides a method of setting the reference
oscillator's 5th harmonic to 124.032000 MHz. It was slightly off, so I
adjusted it. However, the original error did not appear to change.
Has anyone else experienced this discrepancy? Is it possible that the
value given in the service manual is in error?
Fred
K4DII
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