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Old 07-30-2021, 01:16 PM
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Quote:
Originally Posted by Resonance1 View Post
No, turning down the contrast does not reduce the buzz, until it is nearly all the way down and the picture is basically gone. But at any normal level, the contrast does not seem to affect it.
The question was, is the sound good at any contrast setting, even so low that the picture disappears. If both sound and picture fail at low setting, then that is just too low a signal. But if the sound is good (buzz gone) when the contrast is very low, that could be an indication of an intermodulation problem in the common stages that carry both.

Are you able to test the video IF tubes or substitute good ones? What I was guessing at is: maybe one of the IF tubes is bad, causing the contrast to be set to increase the gain in the others to the point where that first one that carries both sound and video is overloaded.
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