[Collins] Ailing KWM-2

[Dr. Gerald N. Johnson, electrical engineer]

Sounds to me as if the PA bandswitch is off a band from the rest of the
bandswitch. Its on 7 MHz when the rest of the radio is switched to 14
MHz.

Or the main loading capacitor circuit is shorted. That could be a
capacitor, wire, switch or user protection choke. Either will achieve
similar symptoms to what you have.

I take your comments on the plate voltage blocking capacitor where you
say "and is leaking DC" to really mean "is NOT leaking DC". You won't
see any DC voltage on the PA network unless the protection choke opens.
There is a choke on the load side of the output network specifically to
short any plate voltage blocking capacitor leakage to ground.

73, Jerry, K0CQ, Technical Advisor to the CRA.


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