My Brand New CTC-7!

[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

[SwizzyMan]

This just keeps getting weirder and weirder. From pin 4 of the 6AW8A to pin 4 trace on the 12BY7A I measure continuity. This makes no sense. How am I getting no filament when the trace carrying the filament is fine? And the grounds are good too. Also I get 5.6 volts on pins 4 and 5 on the 6AW8A socket. Was 1.6v between 12BY7A pin 4 and 6AW8A pin 4 for about 3 seconds then it settled down to 0v. What is going on? Also note there seems to be a wire bridging pin 4 of the 12BY7A to pin 4 on the 6AW8A although the trace that connects the two pins have continuity.

[old_coot88]

Originally Posted by SwizzyMan

...I get 5.6 volts on pins 4 and 5 on the 6AW8A socket.

Are you saying there's 5.6V on both pins 4 and 5 with respect to ground?
If so, pull the tube. Now there should be zero volts on pin 5.
With the tube still removed, check continuity from pin 5 to ground. It should read zero resistance, solid continuity. If it's open, there's your problem.
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Or are you saying there's 5.6V between pins 4 and 5? If so, that's what you should be getting. This would indicate one of the lugs is open inside the socket.
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(For convenience I'm using your 5.6V measurement in lieu of the called-for 6V.)

[SwizzyMan]

well just put in a new wire jumping pin 4 to the other pin 4 and that fixed it. Not sure why it would have mattered but I fixed it and cleaned the tuner. Now to put it back in the cabinet. Fingers crossed for good results!

[Electronic M]

delete

[SwizzyMan]

OK got it back in the cabinet tuner is crystal clear but now I dont have full vertical height and there is a vertical fold on the top of the vertical hold. The fold is about maybe 2 inches. I dont know what is happening now. I replaced the 6AQ5A tube but still no luck

[SwizzyMan]

Alright was able to fix the vertical folding problem. But now I cant get any color! What now?

[DaveWM]

what was wrong with the vert? convergence board not plugged in?

wiggle color osc tube, make sure all tubes lighting in color section, adj fine tune.

[Phil Nelson]

I wonder if you have one or more funky sockets on the boards. That is suggested by an old jumper to a socket pin. Sometimes resoldering pin connections on the sockets can help. Obviously, you want to be delicate with any work on those boards, to avoid lifting traces, etc.

I am curious how you fixed the vertical problem. Intermittency (fixed by wiggling tubes) also suggests bad socket-to-board connections, or simply a bad socket.

Sometimes you can improve sockets by cleaning the devil out of them or (carefully!) bending the metal inside the socket holes to make better connections.

Phil Nelson

[SwizzyMan]

Will go through and resolder all the sockets. And I forgot to mention Dave I did indeed forget to plug in the convergence board my bad. Only problem is my horizontal hold knob is stuck on the shaft. Will heat it up then pull the chassis out for hopefully the last time. Note I did lose color after cleaning the tuner. Could I have messed up something in the tuner causing no color? All I did was go over the copper coils and other moving parts with a q-tip dipped in deoxit.

[old_coot88]

Originally Posted by SwizzyMan

Could I have messed up something in the tuner causing no color? All I did was go over the copper coils and other moving parts with a q-tip dipped in deoxit.

This likely caused osc drift, requiring re-adjustment the fine tuning. It'll probably require a couple more adjustments before it fully stabilizes. The copper coils are not what require cleaning, just the switch contacts.

[SwizzyMan]

Oh no, did I damage the copper coils in the process? And is the osc drift adjustments coil adjustments? Which coils exactly need to be adjusted if needed?

[old_coot88]

Nein! No! nyet!! Don't adjust any coils in the tuner! "Fine tuning" refers to the customer adjustment called Fine Tuning. The Deoxit does't damage anything. It can sometimes cause a bit of temporary osc drift until it's completey evaporated.

[SwizzyMan]

OK not touching any coils. You think the fine tuning adjustments should give me my color back? Because I have messed with the fine tuning knob and I can't get anything. Should I resolder the tube socket pins or just wait for the drift to go away?