Hi Jason,
Since it only happens on 160 meters, I would suspect Y1 on the XTAL OSC.
- L.O. MIXER BOARD (81595). That is the 160 meter band select crystal.
It is supposed to be "locked to a precision reference" according to the
narrative description of that board. My guess is that the adjustment for
that crystal, L12, needs to be twiddled. There is a " DC Correction
Voltage" to this oscillator. I would measure that voltage when using
various bands that are working right, and then see what is happening to
that voltage when on 160. You may be able to tweak L12 to get that
voltage back to something close to what it is on the working bands. If
so, the problem will likely be solved. My guess is that L12 is so far
out of adjustment that the DC correction voltage is all the way to
either maximum or minimum of it's range, and cannot keep the oscillator
locked when on 160 meters. Another possibility is a flaky crystal.
Good luck, have fun.
DE N6KB
I have an Omni 6 that works fine in every way except a slight drift on 160
meters. Every 2 seconds it drifts downward about 20hz and then comes back
to the original frequency, then drifts down again, continuously.
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