I've been blessed!

[old_tv_nut]

Originally Posted by Penthode

If the variance of the +385v supply is that great, something is wrong. On my CTC5, upon inspection before I even powered it up, the ground to the transformer center tap was not properly soldered from new! I never had the opportunity to find if it affected the B supply! But a drop to 330 volts can mean a few things eg bad 5U4 tubes, bad fuse holder of a leaky electrolytic. But if it varies with beam current that would suggest the series power supply resistance is too high: bad weak 5U4 tubes seem the most likely candidate.

That's what I'm thinking - both the time that it takes to drift and the fact that it always comes back to the same starting condition when cold points to tubes.
I ordered a couple, should be here in a few days.

By the way, dragging it from the corner revealed that the convergence plug was not making good contact, and exercising it a bit seems to have restored it.