My Brand New CTC-7!

[Electronic M]

Originally Posted by SwizzyMan

Cant seem to trace it. The foils arent actually traced to another lead it is just a dot of solder. Should I just put in a new socket?

Check the resistance between the top and bottom of the socket. If it checks open replace socket. If it tests like a wire then you are going to have to try harder to trace it since it ain't the socket if you have continuity.

Keep in mind that if you don't have 6.3VAC at the socket solder pads it won't work even if you change the socket. Also if one of the heater pads is supposed to be grounded and the trace or ground lug is bad that will kill your heaters too.

[SwizzyMan]

OK resistance is good on all pins so just going to have to see what the problem is. I did notice that on the other socket next to the problem socket the middle ground lug is there but on the problem socket it looks like it never had that middle ground lug even though a trace hole is there but has a thin layer of solder over it. Would this raise any red flags?

[old_coot88]

OK here's a simplified sketch from the CTC-7 schematic.
There's a second tube on that board, a 12BY7. Is it lighting? (Assuming it is.) It'll have 6V on pins 4 and 5, which are tied together, with the center tap (pin 6) grounded.
There should be a long trace (or possibly a wire topside of the board) going over to the 6AW8, carrying 6V to pin 4. If 6V is absent, look for an open somewhere on that line.
-
If there is 6V on both pins 4 and 5, look for an open ground offa pin 5.

[SwizzyMan]

Hmm that is puzzling, I could have sworn I pulled another 6AW8A out of the 12BY7A socket. Could that have caused the loss of filament on the 6AW8A in the other socket? Then again, I'm pretty sure that there was always a 6AW8A in the 12BY7A socket and I know that at one point the problem tube did glow. Will go and pick up a 12BY7A today just in case and do some investigating on that board.

[SwizzyMan]

Was able to dig up a 12BY7A. The 12BY7 glows but still no 6AW8A glowing. Will investigate more later today like I said.

[Zenith26kc20]

If the 12BY7 is lighting, 6.3 is getting to the board. Check pin 4 of the 12BY7 to pin 4 of the 6AW8 for voltage. It should have none. If you get voltage look carefully for a bad connection or break in the foil.
Look very carefully at the solder on the pins of the 6AW8 tube socket.

[old_coot88]

Here's the full manual if you don't already have it. The schematic is 'waay down at the bottom..
http://antiqueradio.org/art/RCACTC-7...toryManual.pdf