My Brand New CTC-7!

[SwizzyMan]

Turned the set on today and it took a little less than 5 minutes to get full hold and great colors. Is it slowly fixing itself maybe?

[DaveWM]

sometimes things get better with use, I have heard theories that could be moisture being driven out with heat. So try using it and see if it continues to improve.

If not, you need to determine if its an osc prob or a sync pulse prob.
you could try monitoring the voltages of the sync sep tube to see if anything is changing from when 1st turned on to when it settles down.

[SwizzyMan]

Will keep an eye on it. Starting to refinish the cabinet today.

[old_coot88]

I believe you mentioned the h.osc tube (6CG7) is NOS. But it still could be borderline weak, causing the long lag to lock in.
Perhaps one of the kindly souls here could send you a known-good-in-H.osc-service 6CG7.
-
There's a 'quick & dirty' test that old techies used a lot in the field for this kinda problem.
Have the set warmed up and everything locked in. Turn the set off for about 7 seconds, and then back on. It should come on with the horiz fully locked in. If it comes on with lines and there's a delay to lock in, it's a sure sign the osc. tube is borderline.

[dtvmcdonald]

Originally Posted by old_coot88

I believe you mentioned the h.osc tube (6CG7) is NOS. But it still could be borderline weak, causing the long lag to lock in.
Perhaps one of the kindly souls here could send you a known-good-in-H.osc-service 6CG7.
-
There's a 'quick & dirty' test that old techies used a lot in the field for this kinda problem.
Have the set warmed up and everything locked in. Turn the set off for about 7 seconds, and then back on. It should come on with the horiz fully locked in. If it comes on with lines and there's a delay to lock in, it's a sure sign the osc. tube is borderline.

If I try that on my CT-100, the horizontal comes up back in sync ...
but with horrendous ringing and distortion in the left part of the screen.
It stays that way forever, or at least a long as I dared leave it on
being afraid of some a meltdown in the flyback.

And it won't work right unless the set is left of for at least 10 minutes,
when it comes up perfectly normally.

[Zenith26kc20]

I can't remember if I posted this info here but here it is again. RCA developed a fast warm up 6cg7 for their color and black and white tv's. It is a clear top tube, getters on the side. They are designed to warm up in 11 seconds, making sure horizontal drive and sync are waiting when the output tube starts conducting. The wrong type can result in a jump in cathode current at turn on or horizontal lines until the 6CG7 warms up. They are also very reliable but are getting a bit pricey because of audiophiles. It is very important to use this tube.

[SwizzyMan]

Would I be able to find one at the tube store (6CG7 special one)? And should I check the cathode current on the h out tube? Going to pull the chassis out today to do my final checks and finish anything that needs to be done.

[old_coot88]

Originally Posted by dtvmcdonald

If I try that on my CT-100, the horizontal comes up back in sync ...
but with horrendous ringing and distortion in the left part of the screen.
It stays that way forever, or at least a long as I dared leave it on

Is the ringing/distortion in the H sweep itself? Or in the video/video IF chain (does it vary with the contrast setting)?

[roundscreen]

Originally Posted by SwizzyMan

Turned the set on today and it took a little less than 5 minutes to get full hold and great colors. Is it slowly fixing itself maybe?

If the problem comes and goes, You may need to re solder the grounds on the horz board. I should have mentioned this before but forgot. I did it on my set just to avoid a problem. Pointing at one so you can see what they look like.

[SwizzyMan]

Will do after I finish the cabinet.

[SwizzyMan]

OK swapping tube did help and I can get a somewhat stable lock but still it has to heat up for about 3 minutes.

[SwizzyMan]

OK here is the nearly finished set. The lacquering could have gone better but it looks great to me. Here is the set in operation. https://www.youtube.com/watch?v=4kSr...ature=youtu.be Do any color adjustments need to be made and should I adjust the dynamic convergence?

[DaveWM]

Looks great, I would not mess with it just enjoy

[SwizzyMan]

That's what I like to hear! Thank you so so much Dave you are the best! could have never done it without your help and all the other nice people here at VK. It has been A LOT of fun restoring this quality piece of American craftsmanship. Will wrap this project up once and for all tomorrow and use this set for years to come! If you ever have any b&w sets you don't have room for I will gladly take em off your hands.

[Phil Nelson]

Originally Posted by SwizzyMan

Do any color adjustments need to be made and should I adjust the dynamic convergence?

You're done. Don't mess with convergence or anything else. The colors are rich and the flesh tones (always a good test) look natural.

You can tell the convergence is good by watching white lettering that appears in the corners. If convergence was bad, the letter edges would have fringes of wrong colors instead of looking clear and sharp as in the center of the picture.

Congratulations on sticking with this project.

Enjoy!

Phil Nelson