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Done with most of the recapping, but came across an interesting problem that took me a couple of hours to trace down.
The HV seemed to be intermittent for some unknown reason. After a while it became clear that mechanically twisting the shield box over the HV section made the HV change. Take the shield off, and HV was a bit low, but very steady. Put the cover back on, and it would reach maximum HV only if I twisted it with my hand, and it was pretty touchy. Didn't seem to matter if the screws were in place or not. I could find no evidence that putting any mechanical stress on anything inside the HV box mattered.
Finally traced it down to a poor electrical connection between the chassis and the plate on top of the bakelite HV board to which the HV box is attached with screws. I never suspected this at first, because it has a big beautiful solder joint from the bottom of one of its rivets to the chassis and from the top of the same rivet to the plate on top of the bakelite. However, a continuity test revealed that indeed the plate was not grounded to the chassis. Under those beautiful solder joints, the rivet had pulled away on it least one side. Resoldering fixed the bad contact.
Then I found that I had HV with the box off, but not with it on. So apparently, when I was twisting it previously, I was opening, not closing the contact. Readjustment of the height of the metal ring around the 1B3 HV rectifier (which is part of the feedback circuit of the HV oscillator) got things in good shape. Had to raise it up a little on the tube.
Now it has stable HV and one of the nicer 7JP4 pictures I've seen. CRT seems quite strong and sharp.
The set needs realignment, but even without the remaining paper caps replaced yet (they will be soon), this set has no other problems. Will post a picture or two when I'm mostly finished.
Tom
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