[ccomer1955]

I have not measured the line voltage for that socket. Come to think of it, I need to see if the socket at my bench (relatively new set up) is even hooked up correctly (the house was built in 96). I did pull each tube in turn, and when I had resoldered the leads from the transformer to to 6A7, it was a consistent 4.5 at each heater in turn.

By high voltage at the other (yellow) cap, you mean measure it where the line from the field coil and the 42 connect? That would be before the two 70K resistors on the daughterboard, right?
About the DMM, that is a good question. It is a Kein MM200. I have one other (cheap Radio Shack model). I can use both to measure line voltage for the home and get back to you.
Fully unloaded voltage for the rectifier filament sockets (no tubes in the radio at all)=5v but that is with the unknown house voltage.
I apply voltage through a dim bulb tester and variac, so I will need to measure voltage for them as well. I will do so and get back to you.
By the way, with no tubes in the set, the dim bulb doesn't show light at full power with a 40 watt bulb.
Thanks for taking time with this. It seems the 66 can be a troublesome set for many folks.