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Old 09-30-2019, 08:22 AM
trinescope trinescope is offline
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Join Date: Jun 2005
Location: Arlington, TX
Posts: 163
I turned it on this morning and what I noticed is I get inconsistent results from the HV supply. Last night the convergence was pretty bad, but this morning it was a lot better, and the front panel control is still maxed out for best convergence. I measured 22KV at the regulator tube and could not get it lower than that, so I believe the HV resistors in the cage are flaky. Also I have a problem with the red video amplifier that gives the impression of a weak CRT (looks like smear), but testing shows it's the video amplifier having a rising low frequency response. I have not replaced the electrolytic video amp feedback capacitors yet and that is a prime suspect for this kind of problem. The resistors and capacitors are on order as of now. Those resistors are really expensive; I had to go with 85MEG in place of 82MEG since that was all i could find, 100MEG is readily available. Those parts together are about $37.

A question for those who have experience with 15GP22 sets: Is it normal for red to go out of focus at a relatively low brightness? That's what I have, but other than that it doesn't show any other more usual signs of a weak gun like smearing or saturation. With normal video it doesn't appear all that bad.
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Erich Loepke
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