CTC-5 21AXP22 convergence

[old_tv_nut]

I don't have subs for the 1st and 2nd IF, tried the 3rd IF and RF amp, and made no difference. I will try an external AGC supply next to see if I can make it increase gain to the overload point. Maybe some parts values have gone wonky in the AGC. I am also ordering some tubes for the tuner, IF, and AGC.

[Penthode]

Originally Posted by old_tv_nut

I will try an external AGC supply next to see if I can make it increase gain to the overload point. Maybe some parts values have gone wonky in the AGC. .

Hmmm. Yes it could be an agc fault. Does the agc control adjustment make any difference? Cranking down you should observe less gain or lower picture contrast. You at the point when the video clips, you will begin to see the video bend and beyond this rapidly go into overload I guess because of the missing sync affecting the keying action.

I think a separate external bias supply to route out an agc fault is a good idea and best to try first.