|
Don't have a CTC-11 schematic, but since you are grasping ---
IF it's like a CTC-7 with X and Z demods (in one tube), have you tried checking around the demod tube for intermittent voltaqes, or replacing the demod tube? If the picture really is still black and white (not cyan) it's hard to see how the R-Y amp could cause the problem without changing the gray scale tracking. So I'd think maybe the X demod circuit could be the culprit.
Apologies ahead of time if this takes you on a wild goose chase - just thinking out loud.
|