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this one is odd, its a very slow moving snake on vertical line only, no hum bars at all. takes about 15 seconds to cycle thru (beat freq of 60hz and the video sync).
I even have a nearly identical chassis that I have scoped the B+ and see the same low freq beat on top of the B+ ripple (you can see the slow wave work its way thru the B+ on both sets).
I am not sure why it effects one set but not the other. The set with the problem even has a 30mf 220ohn decoulpling off the yoke that the other set does not (this is the only diff beside the audio section between the two sets, the audio of the good set does not use the audio output, it is a console with a sep audio amp). The schematic does not show this decoupling, if just has the yoke connected directly to the B+.
I am tempted to bypass the yoke decouple and make it the same as the non snake set.
No joy finding that book close by or for sale, library of congress was the closest. I will keep trying.
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