CTC-5 Westcott restoration

[SwizzyMan]

Here is what I have now. The picture seems like it could be a lot more brilliant. I cant turn up the color too high or I will not be able to get correct colors. Please excuse the purity issues. Could this picture be improved? It looks a bit better in person.

[old_coot88]

The luma signal (i.e., the black & white or 'video') component is absent. Only the chroma signal is being displayed.

[SwizzyMan]

Could the delay line be causing that?

[old_coot88]

The most frequent causes of loss of luma are 1. Dirty Service Switch (but I don't believe CTC-5 has a Service Switch) and 2. Heater-cathode short in the CRT.
Try tapping gently on the CRT neck with something like a screwdriver handle. That'll usually show up a H-K short.
Other things can cause loss of luma too, including open delay line.

[SwizzyMan]

Looks like I had it in my first picture of the set without the color...

[SwizzyMan]

I also suspect the chroma takeoff and 4.5 mc coil may have something to do with it. The crt checks fine with the H-K so I dont think it can be that.

[Username1]

Originally Posted by old_coot88

The luma signal (i.e., the black & white or 'video') component is absent. Only the chroma signal is being displayed.

He is right ! check the schematic, follow where the video amp is and look
anywhere along the line, don't get stuck on some single part just cause you
know it's name, troubleshoot it along the way.... Contrast control, tube, check
tubes & tube voltages, lose parts, tube sockets, hit stuff and boards with a
nude stick see if it's intermittent, etc. etc....

.

[SwizzyMan]

OK the 4.5mc coil was badly out of alignment so I readjusted that with my scope. I think I now have a pretty good picture for a CTC-5 super. Aside from the purity issues it looks pretty good in person. I will do edge purity and a bit of convergence since the convergence already looks good. Then I will take a look at the HOT cathode current and adjust that if needed. Also going to add a fan to the HV cage to keep the fly cool. And then I may be already done with this restoration!