ctc-10 glitch
 

I recapped etc. this set months ago and has always been working great. Tonight, for about 30 seconds after it had been on a minute or two, the picture broke into basically white horizontal bars which varied in number (similar to if the horizontal hold had been cranked all way over on a white screen). But I also lost the sound, just turned into a rising/dropping whine. When I changed channels nothing changed, same bars/whine. Then boink it came back to normal. Still working now.
Does this maybe sound like the tuning section since I lost ability to tune picture and sound? Could a tuner flaw cause bars like that? thanks!

Something in the horizontal circuits, I would think. Some sets used boosted B+ from the horizontal output flyback to run the audio output.

ok since I didn't hear any arcing or anything, I'll try reseating all the tubes in the horiz section, hope it ain't the flyback but then I wouldn't think it would just come and go away like that. Might pull each tube there and see if the sound goes away and then try replacing that tube too.
Frenchy

Outside interferance maybe? Say a radio operator keying a large amplifier nearby, and overloading the front end. Since it only happened once for 30 seconds.

Bill R.

Ah hah, I guess that is possible! Could it be bad enough to look the same no matter what channel? Maybe I'll just keep the back cover on and wait for it to happen again for now, seemed to do it while it was in process of warming up but you never know.

frenchy,

You have CTC-10, I have a CTC-9. You said you recapped it. Did you replace the brown-maroonish colored capacitors that are in the shape of an orange drop. They have a line at one end and I keep wondering if they are paper capacitors, of which the line indicates the foil side. These capacitors big me, because I want to replace them with orange drops.

Thanks.

Jonathan

Jonathan - I believe those are dipped mylar capacitors. The line means outside foil on a mylar capacitor just like a paper one. Those caps didnt seem to have a high failure rate, though I did find a bad one in my Silvertone recently.

John

I always thought the shiny hard brown caps were already non-paper so I don't automatically replace them. Anyway the set worked fine last night so I'm crossing my fingers that it was some tremendous interference.

When I finish the roundie and fire it up, I'll let you guys know.

Thanks.

Last night it did it again, for only a second though while was first warming up again, so guess I have to take the back off. Right before it does it, it starts getting a a sound buzz and I knew it was going to do it again, then boom right into horizontal white lines briefly.

Check the ground connections on the horizontal oscillator board. They are known for failures. They caused alot of odd problems that my CTC-10C had when I got it in 1975. Good luck.

I'm pretty sure now it was just a dirty connection on the 6AW8 tube on the IF board, it was the only tube causing pix/sound problems when I tweaked it a little, cleaned up the pins and problem seems to have gone away for good now.
Frenchy