CTC 11 Silvertone no Vertical

[Eric H]

First picture.

Hooked up the DVD player and Modulator, the Vertical and Horizontal dialed right in and locked solid, the Vertical is stretched out because the controls were moved when I de-oxed them.

The convergence is terrible but I haven't even attempted to correct it, the Purity ring is sitting on the bottom of the cabinet so it's amazing it looks this good.

Picture is nice and clear, only one thing is missing, no color.

Jiggling the tuner (very dirty) and adjusting the H-Hold doesn't help, color and tint controls do nothing other than a very slight change in the picture tint.

Well at least it's running, none of the tubes or caps in the Chroma circuit have been tested or replaced, I'll start on that tomorrow if I have time.

This set has a Glass 3.58 Crystal, did someone say they are more prone to fail than the metal ones?

[mstaton]

It's possible that it's bad but I bet it's something else in the color circuit. The oscillator may be off slightly. Maybe recap and test the tubes first. Those boards are prone to have bad solder or traces especially if it has high hours on it. I had that issue on a tube socket on my CTC-9 with extreme high hours(on the 6th CRT). Once I figured it out no more problem. It was really hard to see. Move those tubes around slightly in their sockets and see if it changes anything.

[miniman82]

If it's been recapped at all, you might need to do the color AFC alignment on it. It's simple: first make sure the 3.58 oscillator is running by verifying a sine wave on its plate, then ground the reactance tube grid and tweak the osc slug till color bars float by slowly. Remove the ground, color should lock. If not there's trouble farther up stream, or the crystal may be bad.

[Eric H]

We have Color!

I tested the tubes in the Chroma section tonight, surprisingly they were all Silvertone Brand, as are most of the tubes in the set.

The 6GH8 tested good! but I found the 6EM6 Burst Amp was shorted, as were both 6FQ7's, these were the R-Y B-Y Amp and the Horiz Blanking G-Y Amp.

Replaced the 6EM6 with a strong used tube and the 6FQ7's with two NOS Sylvanias.

Fired it up and I could see an immediate difference, instead of a dull gray screen I had a reddish screen with really bad purity, a twist of the Color & Tint knobs verified that there was Color coming through, though terribly inaccurate.

I did a real quick Purity and Gray Scale setup and it looks halfway decent, the convergence is still terrible, partly because the components on the neck of the tube are not very accurately placed, also the Focus control is frozen, though the Focus is fairly decent.

[mstaton]

Nice! Glad it was simple. Not too far now.

[ChrisW6ATV]

Very nice progress!

[Kevin Kuehn]

Lookin' good!

[tvtimeisfun]

Hey Eric great job keep up the good work I admire your tv page keeep us posted... Timothy

[Jeffhs]

I second Timothy's request -- please do keep us posted on further progress with this set. I had a Silvertone roundie TV in the 1970s with, I believe, an RCA CTC12 chassis, just one model up from yours. Mine didn't have as good a picture as yours does, though. I was just starting out with color TV at that point and didn't know a lot about it. Shortly before my set bit the dust when the video output tube crunched through the video PC board, however, I also had color sync problems that would disappear when I'd turn the tint control rapidly from one end of its range to the other, at least until I changed channels.

The other problem this set had that I never got a chance to correct (the video circuit board broke when I was trying to replace the video output tube) was a hum bar that floated up through the picture. That was actually why I wanted to replace the 6AW8 video output, as I thought the tube must have had a heater-cathode short. The tube with which I was going to replace it, however, had a bent pin, so when I tried to plug it into the socket, no luck. Thinking I could get the tube in the socket anyway if I fiddled with it long enough, I tried again, with a bit more pressure on the tube. That was when I heard the fatal "crunch" as the video output socket (with the tube part way in) clunked to the bottom of the set.

[Phil Nelson]

Looks like you're on the home stretch!

Finishing the convergence is good for hours of fun if you're a fumbler like me and those cheap pots on the convergence board are crusty.

I would not go through full-dress convergence until you have completed everything else that needs attention -- tuner cleaned if necessary, recapping really truly done, "black and white" screen geometry correct in both dimensions, and so on.

Not that repeating a procedure is bad, but I don't like twisting those cheesy little pots more than necessary.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[ctc17]

The crystal is new in the one you picked up. The glass one is on my bench, it failed after a few weeks of use. Use that one if needed in the future

[Eric H]

I probably won't get back to it until the weekend, I need more than the five hours a night sleep I've been getting.

The chassis will have to come out at least once more, I need to change out a few more caps, I may not replace any more of the Orange drops but I definitely want to get that Bumblebee out of the Horiz Osc circuit!
Also need to clean the tuner.

I removed a Bumblebee that was across the AC plug, I don't think it really needs it do you? It's a .047 @ 600v and has nice long leads on it, is that the one the Guitar people want? I'll sell that sucker if it is.

There's something Microphonic on the chassis, maybe a tube, but whenever I touch anything like a control on the front panel I can hear it ringing in the speaker!
It's very sensitive, even a really light tap sets it off.

I will save the Degaussing and Convergence until the set is in the location it's going to stay in, wherever that might be.

[Phil Nelson]

If that tuner's the same wafer type as in my CTC-11s, a careful cleaning is a good idea. I cleaned the heck out of mine and it's still a little funky on occasion.

I've been told that hosing down the whole thing with DeOxit (or whatever) is a bad idea and I have no reason to doubt that advice. My current favorite method is rubbing contacts with Q-tips dipped in cleaner.

Some people just remove those line filter caps, but I'm a gullible sort who believes that parts were included for a reason. Our house is so full of RF noise from computer power supplies and whatnot, I figure these poor old TVs need all the filtering they can get.

Microphonics in a set that new seems a little odd. Certainly an issue with some older TVs. The Philco 49-1240 that I just finished has rubber chassis feet to reduce microphonics. Even with soft new feet, you can still get a ring if you tap the tuner knob with a pencil. My RCA T-100 has a thick lead shield on one of the tuner tubes. Couldn't hurt to look at tubes in the front end, anyhow.

Phil Nelson