CTC-5 No luminance.
 

I just bought a restored CTC-5 and I'm having a problem with it, I'm getting no luminance but good chroma. I don't know much about color sets so I'm trying to get a idea what might be causing it? The CRT is good so I don't think it's anything with that.

There is both chroma and luma drive in those pictures, in approximately
correct ratio. The CRT screen and brightness and drive (per color) adjustments
just need correct adjustment, assuming of course that nothing broke between
restoration and your buying it.

Thanks :) and I'm hoping that's all it is. I guess I need to start with feeding it a direct signal from a DVD player or I might even try and get a signal pattern generator. For how good the CRT tests I do have the brightness and contrast turned up pretty high to get that picture I wouldn't be surprised if the drive controls got bumped somewhere along the line. Also here's a video of it https://www.youtube.com/watch?v=EY3R3IIlJas

Check the delay line or the 12by7a tube or parts associated with it.

I believe this set has all its original tubes so it very well may be weak. I guess if I can get my hands on a NOS 12BY7A I'll give that a try to start. Also does anyone have the service manual for this set they would like to sell?

I gots NOS 12BY7As :)

Might be time to buy a tube tester.

Pretty sure he's got one, but I don't think it does many of the post-1960 tubes. We have to get together anyway, he has a GE color portable for me from his recent trip to Detroit :)

That should be fairly easy to trace down with a scope. Straight forward video problem

I do have one and its a rapid tube tester model 82A it pretty much only tests emissions but works ok for a low end tube tester, After looking online for around a hour today I found the tube setup list for this tester as mine is missing at least 1 page and sure enough the 12BY7A is on there, I tested it and it is weak it's on the hi end in the middle questionable area on the tester. I'll try to test all the tubes in this set the tester supports :)

Look's like the CTC-5 will need one :) I was able to test it after all and the 12BY7A test weak. And I'll bring your GE over for you as well :) I got side tracked with the last minute road trip to get the CTC-5 and didn't do much of nothing this past week Lol.

unfortunately I don't have a scope :( I'm still building my collection of test equipment, right now I only have the very basics. Hopefully a new 12BY7A will help, If not I guess I'll have to get a scope.

Just to make one point clear: Luminance or 'Luma' refers to the B&W video component of the picture. That is, if you turn the color completely off, there'll still be a normal B&W pic.
Luma doesn't refer to brightness of the raster itself.

Though if the video (Y) amp tubes are weak, a dim raster can be a symptom.

Test all the tubes in the sets you just got and tomorrow you can come shopping.

Right you are. :yes:

All the unobtanium parts appear to be working fine (CRT, flyback, power transformer and such) and what is broken should be easily obtained.