CTC-5 Westcott restoration

[Penthode]

Originally Posted by old_tv_nut

I recommend modifying the CTC-5 video output stage to the CTC-7 configuration.

http://www.videokarma.org/showthread...ication&page=2

I remember the post. Boy the five years swiftly passed.

I ended up modifying the cathode circuit on the 12BY7 because of the blooming problem. But the green cast at high brightness remained.

I think there is more to do because to drive the CRT to conduct, the 12BY7 current remains too high. If I recall correctly, the 12BY7 control grid bias needs to increase (greater minus). Comparing the CTC5 to the CTC7 or CTC9 should reveal the difference.

[SwizzyMan]

After about 1 hour I lose horizontal sync... which I thought I fixed. After checking back on the horizontal board, I found I did not replace one cap (C606?). Tracing everything in front of it makes it seem like it is a very critical cap. Perhaps the cap drifts as it gets warmer considering its proximity to the 6CG7? Does this seem like a critical cap to you guys? By the way it is the only original component left on the board besides the waveform coil.

[old_tv_nut]

Yes, critical - determines horizontal frequency in combination with the coil (cut off at the top of your image). Replace with the same type / temperature coefficient.

[SwizzyMan]

Originally Posted by old_tv_nut

Yes, critical - determines horizontal frequency in combination with the coil (cut off at the top of your image). Replace with the same type / temperature coefficient.

Thanks for the clarification. After I get that replaced I need to take some shots of the screen. Direct injecting a composite signal works pretty well with a 5.

[SwizzyMan]

Here are some obligatory Oz shots from the 5 before I lost sync. Not pleased with how the camera made these out, but it gives you an idea. Picture is not as bright, but a lot more crisp and clear than displayed on camera. This is taken with a composite video signal injected into the video amp. Not too shabby.

[old_tv_nut]

It looks like your camera didn't focus exactly on the screen. Other than that, the pictures are great. You've got better vertical linearity on yours than I have on mine.

[etype2]

Great, could be focused better.

[Electronic M]

Color level looks a bit high. When skin tones start to glow, look neon, look tan when their not I know to back down the color level a bit. Great picture aside from that.

[SwizzyMan]

Originally Posted by Electronic M

Color level looks a bit high. When skin tones start to glow, look neon, look tan when their not I know to back down the color level a bit. Great picture aside from that.

Well... I do like my colors saturated I'll post some better pictures tonight once I fix the horizontal problem. I was in a rush to take the photos before the horizontal went off.

[old_coot88]

I remember a few customers back in the day who deliberately ran the color wide open. Their attitude was "I'm paying for a color set, so I want all the color it'll make."

[Tom S]

I used to roll the vertical hold till the customer told me which picture looked the best. LOL

[SwizzyMan]

Ok NOW the horizontal is fixed. I fooled with the camera setting a bit and was able to get a darker picture and cant get the camera to focus correctly, but still...the picture is so much better in person. Thanks to Phil Nelson for the A/V input box idea! This TV is ready to move up north.

[SwizzyMan]

There have been these faint vertical lines all across the screen and I have been trying to just ignore it but it is driving me nuts. It goes away when the chroma is turned off so it has to be chroma related interference. Anyone know what these are and how I get rid of them?

[old_tv_nut]

Originally Posted by SwizzyMan

There have been these faint vertical lines all across the screen and I have been trying to just ignore it but it is driving me nuts. It goes away when the chroma is turned off so it has to be chroma related interference. Anyone know what these are and how I get rid of them?

I presume they are stationary? Do they vary in intensity with the color control setting? Can you see them when you have a picture on? Do they move left and right with the picture (or move differently than the picture) when you turn the H hold control a bit?

[SwizzyMan]

Originally Posted by old_tv_nut

I presume they are stationary? Do they vary in intensity with the color control setting? Can you see them when you have a picture on? Do they move left and right with the picture (or move differently than the picture) when you turn the H hold control a bit?

Completely static. More visible when brightness is turned up. They dont move and they only go away when color is turned off. They also go away when there is no signal being injected. I have hooked it up to a cable box and a dvd player and both had the lines. Also move with the horizontal hold.