CTC-4 Director 21

[Bill R]

What I see is video ringing in the earlier picture. Looks like you were on the right track with the peaking coils and such in the last video and IF strip. The color problem is what we used to call poor color fit. More often than not it is caused by a problem or poor alignment of the IF strip. I would set up to do an IF sweep alignment and see what the response curves look like. A proper IF alignment may solve both problems. I will bet it is off more than you think.

[SwizzyMan]

Sounds like an alignment is in order this weekend. Unless I can do it with the chassis on the bench with no hv or crt.

[miniman82]

Uh, that's how you're supposed to do it...

Read the alignment instructions, or better yet if you have a B&K 415 use that it'll cut your time in half.

[SwizzyMan]

Originally Posted by miniman82

Uh, that's how you're supposed to do it...

Read the alignment instructions, or better yet if you have a B&K 415 use that it'll cut your time in half.

Don't have a 415, but I do believe I have all other necessary equipment. Bear with me here, this is my first IF alignment on a color tv. I've been lucky I haven't had to do any till now.

[Phil Nelson]

I like Bill R's suggestion of setting up to do a video IF alignment and viewing the traces to judge whether alignment is a significant problem. That is, look -- following the procedure in the factory manual -- but don't touch any adjusters the first time around.

If you haven't done the procedure before, that would also give you confidence that your setup is correct and you are viewing valid things on your scope.

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

[andy]

...

[SwizzyMan]

Originally Posted by andy

Not trying to hijack the thread, but I'm also working on a CTC4 with some similar problems. Possibly we can help each other.

So far, it's been recapped and I've replaced all the out of tolerance resistors I can find. It produces a reasonably good B&W picture, but the chroma is VERY noisy. It looks like the kind of noise you see if the fine tuning is way off, or with heavy RF interference, but the picture looks good with the color turned down. Sound is also good.

I'm not sure what's normal for a CTC4, but I find that I have to set the color control a lot higher than on most other sets. I suspect it could be a problem with the chroma band pass (misalignment or low gain).

I have not checked the alignment yet other than the basic chroma demodulator adjustments. I can do a full alignment if I have to, but this one looks like a very complicated job.

Your set sounds like a carbon copy of mine. Same problems. It's probably a matter of IF alignment.