RCA vertical problem common to late 60's chassis'

[drh4683]

Ive noticed some unique problems in the verticle section on various RCA tube type TV's, even the CTC-40 solid state chassis. It seems that setting the verticle linearity and or size controls can be very difficult without the oscillator drifting off. Resetting the verticle hold will stop the picture, and it locks fairly well with the control at mid rotation. Upon readjustment of the linearity or size controls, the verticle hold slips again. If you adjust the linearity and size controls just right, you can get the picture to be acceptable and the verticle to lock. Its a very tedious adjustment and its certianly a problem Ive noticed. I just pulled out one of my CTC-38 that had this problem and never looked into it further yet. I had the problem also in a CTC-22 that I once had. Curious if any of you had this similar problem as it seems fairly common in the RCA sets. I never gave it much though as I was always able to make the set work OK, but its really not working like it should as there are other sets which can adjust in seconds no problem. I havnt pulled the chassis to check this out on my ctc-38 yet. Perhaps others have experienced these similar symptoms. Anyone know the cure to this? Im going to check out the set later on this week.

[sampson159]

every rca i own has or had a vertical problem.i have 3 roundies(ctc15) and all of them needed vertical centering pot replaced and also one needed height control replaced. i have a ctc16 with a 25axp22 that needs both! these are really good sets,but those vertical controls are a headache!