Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Early Color Television (http://www.videokarma.org/forumdisplay.php?f=36)
-   -   CTC-4 Director 21 (http://www.videokarma.org/showthread.php?t=267400)

SwizzyMan 08-23-2017 09:22 PM

Quote:

Originally Posted by miniman82 (Post 3188572)
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 08-24-2017 01:26 PM

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

SwizzyMan 08-24-2017 03:48 PM

The alignment instructions for this seem pretty involved! Don't know if I am quite up to the task yet... Can anyone lead me in the right direction? If push comes to shove I'll just try and build a video preamp.

Phil Nelson 08-24-2017 04:19 PM

Do you have a restored B/W set that works well, that you could use to practice alignment (again, doing the setup and looking at the traces, without changing adjustments)? The setup wouldn't be identical, but maybe that would help you get the hang of things.

I had reached a similar point with my CTC-4 and I took a stab at building a video preamp, which turned out to be not as simple as I hoped. This old thread has more details:

http://www.videokarma.org/showthread...259995&page=23

The last color bars that you posted look pretty good, apart from that one anomaly. What does the TV look like when you view regular content, such as a DVD or cable TV? Sometimes things that look less-than-perfect in test patterns don't interfere much with everyday viewing.

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

SwizzyMan 08-25-2017 05:11 PM

Quote:

Originally Posted by Phil Nelson (Post 3188627)
Do you have a restored B/W set that works well, that you could use to practice alignment (again, doing the setup and looking at the traces, without changing adjustments)? The setup wouldn't be identical, but maybe that would help you get the hang of things.

I had reached a similar point with my CTC-4 and I took a stab at building a video preamp, which turned out to be not as simple as I hoped. This old thread has more details:

http://www.videokarma.org/showthread...259995&page=23

The last color bars that you posted look pretty good, apart from that one anomaly. What does the TV look like when you view regular content, such as a DVD or cable TV? Sometimes things that look less-than-perfect in test patterns don't interfere much with everyday viewing.

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

Still isnt great while viewing programs. Ghosting and the picture looks overdriven which may be to the fact that it is hooked directly up to the cable box. I don't think IF is an option for me now. If it really needs to be done I guess I can try it.

old_coot88 08-25-2017 06:12 PM

As Phil suggested, practice alignment on a BW set. You don't wanta jump on a full dress Harley without being proficient on a more basic bike. :)

Phil Nelson 08-25-2017 07:18 PM

Regarding a video preamp, I just updated my CTC-4 article with a new section at the end, describing what I built:

https://antiqueradio.org/RCACTC-4ColorTelevision.htm

My preamp didn't work, due in part to a wiring mistake. I fixed that and messed around a little more, and then pushed the whole thing aside because I was burned out on the project.

Anyhow, I have to believe that the basic design, taken from the 1956 article in RCA Broadcast News, will work if someone takes the time to build it correctly.

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

SwizzyMan 08-25-2017 09:48 PM

Quote:

Originally Posted by Phil Nelson (Post 3188678)
Regarding a video preamp, I just updated my CTC-4 article with a new section at the end, describing what I built:

https://antiqueradio.org/RCACTC-4ColorTelevision.htm

My preamp didn't work, due in part to a wiring mistake. I fixed that and messed around a little more, and then pushed the whole thing aside because I was burned out on the project.

Anyhow, I have to believe that the basic design, taken from the 1956 article in RCA Broadcast News, will work if someone takes the time to build it correctly.

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

Wow, that will definetly be project... Hell, I'd pay someone to build me one.

andy 08-26-2017 11:05 AM

...

SwizzyMan 08-26-2017 09:30 PM

Quote:

Originally Posted by andy (Post 3188722)
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.


All times are GMT -5. The time now is 06:01 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.