[ghjkl67]

Okay, now I'm starting to understand why the grid and plate need to be in phase. I just have to think of that 2A4G curve scale as being DC, then take the instantaneous AC voltage. Sorry for being a little slow here.

sean,
Yes, I did check resistors. The ones in the grid circuit look good. I changed one out in the control receiver circuit some time ago. It was the 99k ohm resistor going to the grid of the 6J7G. The B voltages there are still a little low, but they are slightly low in the whole set.

As long as I ordered the new tube, I'd rather wait until that comes before changing the transformer wires. They are very brittle and somewhat difficult to solder. If the NOS tube doesn't fix it, I'll try swapping the transformer wires. Meanwhile, I'd like to try scoping out both the grid and the plate to see the phase relationship. Would an isolation transformer be necessary for the scope?