The CTC-5 Made it to Germany already!

[yagosaga]

Originally Posted by Sandy G

Yagosaga- Awwww, man, that's a nice picture !!! You've done an EXCELLENT job...Congrats are in order. I was a bit resentful at first that one of these guys had left the country, but now that I see how you've treated it, the "love" & respect you obviously show towards it, I don't think it could be in better hands.... My hat's off to you, sir !! -Sandy G.

Thank you very much for your friendly words. Yes, I love these old sets since decades. For me it is a honour to serve one of these treasures. We usually don't get no full tube color tv set here in Europe. The eldest sets are hybrid sets. And I remember when I was a pupil and later a student 25 years ago, I repaired many color tcv sets from the 1960s. Most of them had weak crt's, with bad red guns. I have learned to revival those sets without any brightener like you know in the U.S., alone by fine adjustment of color drive, screen background etc.. in this case here with the ctc-5, it is much easier. It's crt ist still strong. And the owners before did a good job with recapping and cleaning the chassis.
This is not the only ctc-5 here in Germany. A friend of mine has one (but not in working condition) and even a ct-100.

Originally Posted by Steve K

Wo ist Brunswick order ist das Braunschweig? ...Steve

It is Braunschweig, near Hanover. You can write in English to me. Deutsch is a terrible language (this already said Mark Twain). I can read English much better than write it.
When I come to America the next time I hope, I can visit the Early Television Foundation. (Some members of my family live in the french part of Canada.)

[yagosaga]

Originally Posted by roundscreen

Check the high voltage to the crt, Is it around 22kv?

It is 21kv (with dark screen), 20.8kv with bright screen. The next values follow when I have enough time to remove the chassis and find a solution to operate it outside the cabinet.

[roundscreen]

Eckhard. That is wonderful. Such a Great picture on that set. looks to me you know what you are doing. If i recall correctly. I put the chassis on it's side. The hi volt cage on the bottom. The yoke wires are short but you can turn the chassis so the wires reach. Please look out for the yoke socket. It moves when you plug the yoke in or out. {Not mounted to well} Convergence wires. hi volt and the crt wires should be long enough. {please be careful of the crt}. Also connect a ground wire to the ground tabs up front were the chassis slides in. For extra protection you can use rope or wire to hold the chassis in place. Tie one end to the chassis and the other to the cabinet. { like when you tie the christmas tree to the wall so the cat can not knock it over} This may sound strange, but Next to the transformer park I want you to build a test meter park. One meter for b+. One for horz current and your hi volt probe. Once you know all the readings are ok {horz-reg current,} Put the chassis back in the cabinet, Hook up the meters and run the set for 15 minutes. Check the readings, shut the set off ,discharge the high voltage {ground wire to the 3a3} and put your hand on the flyback{ It should not be hot}. Turn the set back on and do it again. This time run it for 30 minutes. then 45 etc. When you hit 60 minutes the fly will be warm not hot. check your meter readings. Look out for drift:{ big changes in current reading, b+ and hi voltage} I like watching the meters. How the readings change with the action of the picture or when the set warms up. Do this for a week or so . get a feel how the set runs. That way you know there is not a problem. I had meters on mine for a month . The ctc 5 runs like a bitch once you get the bugs out of them. I haven't had to do any thing to mine in years. Such a cool tv .

ED

[yagosaga]

Originally Posted by roundscreen

If i recall correctly. I put the chassis on it's side. The hi volt cage on the bottom. The yoke wires are short but you can turn the chassis so the wires reach. Please look out for the yoke socket. It moves when you plug the yoke in or out. {Not mounted to well} Convergence wires. hi volt and the crt wires should be long enough. {please be careful of the crt}. Also connect a ground wire to the ground tabs up front were the chassis slides in. For extra protection you can use rope or wire to hold the chassis in place. Tie one end to the chassis and the other to the cabinet. { like when you tie the christmas tree to the wall so the cat can not knock it over}

I'm not really happy with this construction. The ctc-5-chassis is the heaviest tv-chassis I've seen in my life (and the sets I've seen are unnumbered in the last 30 years). It is still very strange for me. One moment of inattentiveness and the falling chassis hit the neck of the crt, and the game is over.
I see two solutions:
- First I construct a wooden frame for the chassis outside the cabinet, which holds it in a safe way.
- The second solution: I solder some wire at the measure points on the chassis and install a "soldering border" (= correct words? In German we say "Loetleiste") inside the cabinet for the wires. Every wire gets a paper mark with it's connection on the chassis. So I can put the chassis inside again and have measure points for future evaluations. I prefer this second solution.
With the test meters, there is no problem, I have enough, and I have enough connection wires too (in German we say "Krokodilsklemmen"). And if I haven't enough, I ask my 11 year old son... ;-)

Originally Posted by roundscreen

... Look out for drift:{ big changes in current reading, b+ and hi voltage} I like watching the meters. How the readings change with the action of the picture or when the set warms up. Do this for a week or so . get a feel how the set runs.ED

Yes, to get a feeling is the most important thing. For every vintage set which I have repaired I needed time to get a feeling for it. At first to understand the schematics, then to watch the set in operating modus. American and German tv sets are very different. The Germans are not so heavy and robust but seem to be more complicated, especially the color hybrid sets.

[roundscreen]

Yes your solutions are much better. Here we call the old chassis boat anchors.

[Steve K]

(= correct words? In German we say "Loetleiste")

I believe that a Loetleiste is a "terminal strip." It is interesting that in German you call them Krokodilsklemmen (crocodile clamps) we call them alligator clamps!

Steve

[yagosaga]

Originally Posted by Steve K

It is interesting that in German you call them Krokodilsklemmen (crocodile clamps) we call them alligator clamps!
Steve

That's really interesting! You have alligators in your country and therefore you have alligator clamps. The correct German expression has to be lizard clamps (= Eidechsenklemme), for we have neither crocodiles nor alligators but only small lizards in our country. But "Krokodilsklemme" sounds much more exciting. See you later, alligator...

[old_tv_nut]

I think I recall reading a German patent about "Bildroehren" (picture tubes) that featured "electronenkanonen" (spelling?) I got a kick out of picturing large-bore cannons (we would say electron guns) in the neck of the tube.

Congratulations on the great results you are getting.

[yagosaga]

Originally Posted by roundscreen

Hook up the meters and run the set for 15 minutes. Check the readings, shut the set off ,discharge the high voltage {ground wire to the 3a3} and put your hand on the flyback{ It should not be hot}. Turn the set back on and do it again. This time run it for 30 minutes. then 45 etc. When you hit 60 minutes the fly will be warm not hot. check your meter readings. Look out for drift:{ big changes in current reading, b+ and hi voltage} I like watching the meters. How the readings change with the action of the picture or when the set warms up.

I did it tonight. The readings of the test meters:
Start: b+ 371v, horizontal output current 210ma, high voltage 21kv
15 minutes: b+ 372v, horizontal output current 210ma
30 minutes: b+ 374v, horizontal output current 210ma
45 minutes: b+ 372v, horizontal output current 210ma
60 minutes: b+ 371v, horizontal output current 210ma.
No significant changes.
High voltage vary with brightness and contrast. With brightness and contrast at minimum it is 21.3kv, in "normal" position with the best picture it is 21.8kv, but with contrast and brightness at maximum I get a bright and wishywashy picture. High voltage declines down to 13.9kv.
The flyback was a little warmer after 15 minutes and very warm after one hour, not hot, estimated temperature appr. 50 to 55 degrees celsius.

[yagosaga]

While testing this morning the video signal disappeared (with a delay time of one or two seconds). No sync, picture with full contrast control has few contrast, and looks inverse, like a film negative. Sound ok, color seems ok too. With no tuner input signal, a contrast rich noise (snow) is on the screen like before in such cases. I assume a defect video detector (1N60).
Testing the first video amplifier tube 6aw8: first grid and positive end of video detector 2.7v instead of 19v, kathode 8.2v instead of 22v, anode 217v instead of 148v, 2nd grid 188v instead of 170v.
Kathodes of the crt appr. 310volts. Do you know this failure?

[yagosaga]

screenshots, left with input, right without input.

[yagosaga]

I have found the defect. It was not the video detector but the A.G.C. circuit. The A.G.C. amplifier (pentode of the 6U8) was very weak (tested with Funke W19). At the anode there were only -1v. It has to be appr. -31v. With the new 6U8 (european ECF 82) the set is working properly again. -76v (??) at the anode.
The schematics for the ctc-5 are online here:
http://www.mcmlv.org/Archive/Radio/CTC5A.pdf

[roundscreen]

Eckhard. Please check c127 470 mmf.{pf} This cap might be leaking. That may be why your -31v is showing -76v. Could you please tell me the chassis number of your set. ctc5 a,b etc. The schematic on line does not match up with mine. I must have the wrong one. Also i would like to try and lower the horz current .
Ed

[yagosaga]

ED: C127 I have checked yesterday with a voltmeter, but it seems to be ok. I will test it with a capacitor tester (500v, 1000v) or will renew it the next time when I remove the chassis.
The chassis number is CTC 5E, RVA L4, 2746443.
I have checked the horizontal oscillator tube V601 (6CG7) with the Funke W19. I found a short between heating and kathode in one triode system.
Another defect appears while watching strong red colored parts of the picture. When I increase the color contrast, red peaks became black. This also happened with green peaks, but so evident. V703 (12AT7), the G-Y and R-Y demodulator, was also bad, had low emission on both systems, I have renewed it.
BTW: I have a field service manual as a pdf file (appr. 7 MByte), I can send it to you.

[roundscreen]

Eckhard. Please send your manual to roundscreen@aol.com. Thank you. Also i am going to dig out my ctc5. I want to be on the same page. If C127 looks like a brown or tan square disk with color dots on it. Just replace it. Did the replacement of the 6CG7 do anything to the horz current? C114. The cap you were talking about {.1 } Bugs me.{Now that i know what it is}. I would like to take a closer look at it when i get all the correct info.
ED