Restoring a 1963 Admiral ctc-12 clone

[miniman82]

I haven't read the whole thread, but it could be a luma issue. Have you replaced the bypass cap on the contrast control? It's in the cathode circuit of the 3rd video tube, if it's not working correctly it can cause the bias on that tube to drift making scenes vary in apparent intensity- reality is you've lost degeneration on that tube to some degree.

[timmy]

Originally Posted by miniman82

I haven't read the whole thread, but it could be a luma issue. Have you replaced the bypass cap on the contrast control? It's in the cathode circuit of the 3rd video tube, if it's not working correctly it can cause the bias on that tube to drift making scenes vary in apparent intensity- reality is you've lost degeneration on that tube to some degree.

would that cap possibly be a 0.1 or .22 ? or the 2- 390 caps because this may be something that is not right on my set as well.

[miniman82]

No, it's an electrolytic cap. RCA service sheet has it as C124D, so it's likely a section of a multi-section can. Scroll down here, and look at the cathode of V708.

http://boxcarcabin.com/rcaschematics.html

[timmy]

i know my eyes are getting bad but i cant seem to find v708 in that schematic, is it infact there ?