ctc 10 power tuner

[zenithfan1]

Originally Posted by hudsonhornet

I'm the previous owner of this set. Glad to see that you think tvcollector was 'lucky' - I hope this beast continues to cooperate and comes back to life. It was completely undisturbed for about the last 15 years. That power tuner looks like quite a nightmare! Hoping to see more updates soon. Good luck.

Of my CTC-7 Anderson too Thanks again for ending a long search! Gonna finish it as soon as I get a place! Sorry to hijack thread....back to your regular scheduled programming.....


This CTC-10 is beautiful! I love it! Glad it went to a "loving" home!

[6GH8cowboy]

The CRT cathode volts plunge down to 175 if the brightnes cont is advanced. The range is way too wide. In looking at the Sams I dont see a signal path for video between the Video amp and Video output. I"m sure it's a Sams oops. The Vid-out grid is way positive from what it should be at a normal setting of the brightness control. I think these two stages are likely direct coupled, but I want to make an educated guess before going further or pulling the chassis again. Any body have insight of a description of the circuit?

[DaveWM]

check the blanker grid, there are a couple neon light in that blanker circuit as well. I guess they are there to regulate the voltage tapped off that grid as well, all tied into the brightness control circuit. did you replace the 2uf cap?

[6GH8cowboy]

Wow Dave. Pulled two to replace it, got a phone call, finished replacing the Vert cathode cap. Just looked on the bench and there the two 1s at 450 layin there. Think I can slide the chassis back enough to do it in set. That could well be the source of the extra positive on the Vid-Out grid. Didn't notice any neon lamps in there, maybe a production change along the way
Thanks

[DaveWM]

Originally Posted by 6GH8cowboy

Wow Dave. Pulled two to replace it, got a phone call, finished replacing the Vert cathode cap. Just looked on the bench and there the two 1s at 450 layin there. Think I can slide the chassis back enough to do it in set. That could well be the source of the extra positive on the Vid-Out grid. Didn't notice any neon lamps in there, maybe a production change along the way
Thanks

look on the grid of the blanker tube, they do not show on the pcb, so prob in that chroma hand wired area. Hopefully the cap will take care of it.

[6GH8cowboy]

Turned out not to be too much positive voltage but, not enough negative. Someone replaced two resistors R-64 and R-135 (Sams) with values that in total equated to three times the original value. There was not enough negative voltage getting to the brightness control to pull it back enough from positive, thus the sky high grid volts. One of these was on a terminal strip on the top rear of the chassis. This was a factory location but seem like an odd place for it.
Next stop is the seemingly high Horiz cathode current @225 ma. Sharp dip when adjusting the eff coil and drive and grid bias is good. May be possible aged transformer that will have to be tollerated.