What causes this? RCA ctc 17 ad x

[BandDirector]

It's like it loses power, rolls, then comes back nice and strong

... where to start with this monster, the fact that it works means I don't want to ruin it.

Also, do I have to make a tool that discharges the crt when I finally get brave enough to pull it?


Edit: The more I think about it, and try to figure out what to study about it, the more I wonder if this is directly related to amplifying the video signal. Perhaps the video amp tube is going bad; or the circuit itself is just old, I had a tube pop and flash a few times before I replaced it. But the greenish 1/2 cast/shadowed pic (and sometimes rolling) will still come back. That said, after the set is on for a good bit it does usually stop.

Or, is it in the tuner/mixer/amp stage, I wonder if the incoming signal (from a dvd/vhs/dvr with digital tuner) is getting messed up then returns to normal. Again, most of the tubes are unaltered by me, just a few here and there as I mess around. Haven't touched the chassis components.

Or, could the high voltage be the culprit...