CTC-5 Westcott restoration

[jr_tech]

Possibly a reasonable test would be to simply by-pass the delay line and observe if contrast is greatly improved? :

Of course the picture would be a little strange looking, as the luminance signal would be slightly ahead of the color signal, but it should give you an indication of the operation of the delay line.

jr

[SwizzyMan]

How would I replace the delay line if it might be bad? The setup procedures did not seem to do anything. Maybe something in the contrast circuit could be bad?

[SwizzyMan]

Starting to think that the delay line is not the issue here. I can get an OK crisp picture but only with the contrast, color,and brightness turned down pretty far. Only watchable in a dark room. I checked two of the pins on the 12BY7A video output tube (plate and screen grid) and found that both voltages on the pins are off. This must be an issue with a resistor in the 12BY7A portion of the board. I must note I wired in parallel two 1 uf film caps to create a 2uf cap to replace the electrolytic that was there. The schematic calls for a 2 uf cap but the one I removed was an 8 uf. I never found any production changes stating that a 8 uf should be used instead of a 2 uf. Maybe I should try an 8 uf?