CTC-4 Director 21

[Bill R]

Originally Posted by SwizzyMan

After leaving no stone unturned in the vertical circuit (which isnt many). I found only one barely out of tolerance resistor a 2.2meg 1/2w coming off G1 of the 6AQ5 vertical amp then goes to ground. Not sure it is too critical and its just barely off spec I mean like less than 1% off spec so I might just leave it. All caps are fine except I did replace a .039 which comes off the plate of the vertical amp and goes to the red cathode of the CRT. The original the maroon drop cap tested OK but I had a cap on hand and replaced it. Dont think it will make the vertical any higher though..

I would probably replace that resistor. Also how does the B+ look? 380V? Also I might replace c169 even if it tested good. Also don't rule out a weak tube.

[miniman82]

Lack of height is nearly always drifted dropping resistors coming from B+boost so look at R119, the height pot, R117 and R118. If they all spec out, lower the value of R119 till the picture fills the screen. If I had to guess our vertical output transformers are going soft slowly, only solution is to feed them more voltage. Those are Sams resistors BTW.

[SwizzyMan]

Originally Posted by miniman82

Lack of height is nearly always drifted dropping resistors coming from B+boost so look at R119, the height pot, R117 and R118. If they all spec out, lower the value of R119 till the picture fills the screen. If I had to guess our vertical output transformers are going soft slowly, only solution is to feed them more voltage. Those are Sams resistors BTW.

All check out fine. R117 is just barely in spec but I don't think that this will be an issue. B+ is 399 but know that I havent added any dropping resistors to the 4007 diodes in place of the seleniums so that should explain the high B+. Looks like I need to experiment with different values for R119.