CTC-7B Basket Case

[sean]

I got this rough CTC-7B from RobtWB a couple of years ago. The original thread about this set is here:

http://videokarma.org/showthread.php...highlight=ctc7

I finally got around to starting on it a couple of weeks back. I had done a preliminary cleaning when I first got it and checked the flyback and the CRT at that time also. Both checked out fine. I started out by re-stuffing the electrolytics and replaced the paper caps and bad resistors in the horizontal and vertical sections as well as the HV section. Last week I powered up the set with the vertical and horizontal output tubes removed just to make sure I could get B+ and get the horizontal oscillator working. Today I hooked the chassis up to the CRT and yoke and slowly brought it up on the variac while monitoring both the line current and the B+ voltage. I was able to get a raster on the screen.



I checked the HV and was getting about 10kV. Adjusting the HV ADJ pot made no difference except when set at one particular spot the voltage would jump to about 20kV. I pulled the chassis again and found the HV ADJ pot was open. I replaced it and powered the set up again. I could now adjust it for a pretty solid 22.5kV regardless of brightness. I thought I would the set up to the cable TV source and see if I could get anything. After fiddling with the tuner I was able to get some images to start coming through but no sound.



I still have a lot of capacitors to replace and resistors to check but at least the set is coming back to life.