CTC-120 ColorTrak - Videokarma.org TV - Video

zenith2134 · #1 06-09-2011, 04:11 PM

recently acquired a few tv's and this is one of them.

It's a 1984 model, 19" (19VLNP22, RCA) with the LED readout tuner/keypad but a hard switch for mains power and volume. (non remote set)

Very good picture. The greyscale/kine. bias was slightly off but it looks awesome now . I am actually a huge fan of 80s RCA colortraks (from about ctc-89 to 140).

Only issue with this one is the tuner module..it has some video noise in the form of waves (sound getting into the picture) until it warms up. I had this happen on a ctc-97 with a similar MTT module box...had to reflow tons of tiny connections inside it and also clean up the ground-plane wiring and stakes on the IF subboard.

Somewhere in the net there was a bulletin saying that the multi-section can capacitor at the back of the 120 chassis has to be changed out. Apparently, one of the sections gets excessively leaky.

Pics soon

radiotvnut · #2 06-09-2011, 04:20 PM

I've resoldered a lot of loose connections in the tuner/control module in those sets. I've also replaced a lot of those filter cans. There is a variable cap in the chroma circuit that will either fail or fall out of adjustment, causing no color. Otherwise, these sets were very reliable.

zenith2134 · #3 06-09-2011, 06:41 PM

Yep, it is the first 120 i've owned. I liked my ctc-117a the best from this era,, it was a very nice colortrak model with o.s.d.

That being said, this one has just as good of a picture.

wa2ise · #4 06-09-2011, 08:53 PM

Quote:

Originally Posted by zenith2134

Only issue with this one is the tuner module..it has some video noise in the form of waves (sound getting into the picture) until it warms up.

In the CTC121, there's an adjustable coil in the IF strip that one can tweak to get rid of the sound getting into the video. The IF is mostly a SAW filter, but there was a coil or two that could be adjusted. I don't remember specifically which coil it was though. The CTC120 may use the same.

Findm-Keepm · #5 06-10-2011, 06:51 AM

.....that would be the discriminator coil, L201. Common problem with those RCAs. Components age, and things get to the fringe. A slight tweak brings it back to center. Check/align when it's warm, then check from cold the following day.

Cheers,

zenith2134 · #6 06-10-2011, 01:12 PM

Thanks for the tips about that chroma coil. I seem to remember a local tv tech mentioning how if it was a smoker's set, the coil would get clogged with nicotine or whatever it is, and cause intermittent color.