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Old 12-07-2025, 10:52 AM
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Quote:
Originally Posted by Penthode View Post
...So first three questions:

How long a period does the darkening occur?

Have the capacitors been replaced around the 12BY7?

Has the contrast control 12BY7 cathode modification been made?
Thanks.

The darkening continues over 5 to 10 minutes, but fast enough that you can see a change in under 30 seconds to a minute.

I gave the set had a total recap when I first got it.

Yes, the contrast modification was made. In the category of full-disclosure of dumbness I accidentally wired the contrast control backwards, so max contrast has been CCW ever since, but I think this can't have anything to do with the problem because it's capacitively coupled in the rewired configuration, and besides, it worked fine after reconfiguring.
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