CTC 21 Console Aquisition

[zeno]

Very strong CRT. The conv problem is mostly center conv. When you
get the center good the edges will follow. All the controls on the conv
PCB are wire wound so they feel "scratchy" compared to to regular
carbon pots.
For the color first turn off AFT or AFC if it has it then put back on after
fine tuning. You can also turn the color killer control all the way off.
The set uses a bunch of 6GH8 tubes so pick up some of those NOS, they are
nothin but trouble. The 6GH8 & there sockets were the biggest fault of
these sets !
You are off to an excellent start with this one, nice buy !

73 Zeno
LFOD !

[TVTim]

Originally Posted by zeno

Very strong CRT. The conv problem is mostly center conv. When you
get the center good the edges will follow. All the controls on the conv
PCB are wire wound so they feel "scratchy" compared to to regular
carbon pots.
For the color first turn off AFT or AFC if it has it then put back on after
fine tuning. You can also turn the color killer control all the way off.
The set uses a bunch of 6GH8 tubes so pick up some of those NOS, they are
nothin but trouble. The 6GH8 & there sockets were the biggest fault of
these sets !
You are off to an excellent start with this one, nice buy !

73 Zeno
LFOD !

Is a 6GH8 and 6GH8A the same?

[DavGoodlin]

Originally Posted by TVTim

Is a 6GH8 and 6GH8A the same?

Generally yes and 6GH8's are descendants of the 6U8 and 6EA8. There is an article I need to find on what was "improved" on the -A, possibly only improved filament warm-up time, as they were used in some series-wired filament (transformerless) TV's.

[dieseljeep]

Originally Posted by zeno

Very strong CRT. The conv problem is mostly center conv. When you
get the center good the edges will follow. All the controls on the conv
PCB are wire wound so they feel "scratchy" compared to to regular
carbon pots.
For the color first turn off AFT or AFC if it has it then put back on after
fine tuning. You can also turn the color killer control all the way off.
The set uses a bunch of 6GH8 tubes so pick up some of those NOS, they are
nothin but trouble. The 6GH8 & there sockets were the biggest fault of
these sets !
You are off to an excellent start with this one, nice buy !

73 Zeno
LFOD !

IIRC, the CTC21 only has only one 6GH8 plus a 6KE8 in the color circuit.
It still good practice to have a few extras on hand.

[DavGoodlin]

Originally Posted by dieseljeep

IIRC, the CTC21 only has only one 6GH8 plus a 6KE8 in the color circuit.
It still good practice to have a few extras on hand.

Thanks for the reminder Dave, I knew there was a reason this chassis stood out alongside the CTC25, 28, 30 and 35. The 6GU7 was a better color difference amp than the 6GH8's triode, and those 4-PCB chassis' proved it.

The CTC38 (and several before it) were consummate 6GH8-eaters

[mr_rye89]

Yeah I only found one 6GH8A in the set, which tests good, I'm gonna check the solder joints at that socket and a few other places.

Now when I set up the purity, do I just feed the set a "blank" signal? I don't have a crosshatch/colorbar generator, Ive just been using the picture viewing feature on my DVD player, with various patterns of course.

In the mean time enjoy some badly converged Star Trek