I still have my CTC-120... It is the first TV I ever bought, in 1993 or 94, when I was a teenager. My parents had bought a new 27" Sony for the living room when we moved into the new house and the now "spare" old Admiral 19" color that I used in the basement died. The repair shop wanted some ridiculous amount to attempt to fix it, so if I wanted a TV down there I would have to buy my own.
I should have
tried to fix that Admiral myself, though, I probably could have fixed it, even then.
I found the RCA in the Bargain Finder. I think I paid $220 for it. The seller said they had two similar 25" RCA models (seller was claiming 28") and said I could have either one. One was my cabinet (model GJR641) and one in what I believe is the same cabinet Kamakiri has, I've seen that cabinet before. The day we took the van over to pick it up the seller had taken one of them to storage but I figured I wanted the one I have anyway (it looked a bit more modern) although they did say they thought the other one had a "clock" on it. I later learned this was the optional "OSD" module which had perhaps a clock and maybe showed the channel numbers on-screen? I can't seem to spot the info in the SAMS right now other than the picture of the "MSD001" OSD board but I thought somewhere in there it said what it did, I'll have to look more closely.
I haven't used it for years but it's in my living room...
I really should get it back up and running, been sitting there far too long!
It
was working until.....
I started adjusting it one day as I tend to do every 5-10 years on my daily-use type sets just to touch things up and had the brainwave to actually get a service manual for the ol' girl since now that everything is on the internet, it would probably lead me right to one. I ended up buying the SAMS for it, printed it out on 11x17" paper and set to work reading up on adjusting everything I could since I finally actually had a SM. Makes sense, right?
I started reading along and was looking at what all I could adjust, and another brainwave,
"Hey, Wait! I have a 'scope! I can do most of this stuff properly!" Even though I didn't yet have equipment to sweep and whatnot, I figured I could at least do most of the adjustments where you check and adjust levels and such based just on waveforms, so I pulled out my scope, set it on top of the TV and dove right in, checking and adjusting.
Then, disaster struck... I had stupidly clipped an aligator clip lead onto the probe I was using on the oscilliscope, precariously running up and across to the scope while I was probing something like the video signal levels around the video processor IC. The aligator clip slipped off the probe tip and fell into the horizontal output area. (GASP!! EGADS!!) I still had color bars at that point yet, even
more stupidly, instead of quickly pulling the power and retrieving the lead, I grabbed at it and it fell down farther into something high voltage... POP! I looked up at the mirror in front of the set and instead of color bars, I had black screen with a faint raster... ARGH!
Horrified, I started looking at the schematic to see what I'd killed based on where I was probing and realized it would be U701, an RCA 153685. "
Oh great," I'm thinking, "
I'm never going to be able to find some proprietary RCA 153685 chip for a 20 year old TV." Bewildered, I started reading through the SAMS and when I get to the semiconductor table, lo and behold, SAMS to the rescue. The chip crosses to a standard ECG/NTE number! NTE844! Perhaps there is hope after all...
I called up the local electronics place I use that stocks NTE and, thinking they've probably been long discontinued, sheepishly ask if they happen to still have an NTE844. Not in stock, but they can still order one... Hooray!
I got it a couple of weeks later but since I'd been looking at the schematic and I'd pulled the datasheets for various manufacturers versions of the NTE844, I realized that I could probably bodge an S-Video input on there right at that chip (it is the chroma/luma processor) so I started building a little extension board with a socket for the NTE844 and room for some switching circuitry to add the video input. Procrastination and other, more pressing projects set in and there it still sits... The NTE844 still in it's bag atop the TV. The little board I started building is sitting atop the TV. The SAMS is sitting right there. I'm ashamed to admit it but it's probably been sitting there for almost 10 years now...
I started trying to make a video about it a couple of years ago when I first found Bob Andersen's YouTube channel and got the bug to work on some older stuff again but I didn't have a video camera good enough to get any kind of quality. I should try the little Cannon digital camera I have here now. It's video abilities might be good enough for a start, since I really would like to post some YouTube videos of some of the stuff I end up working on. I think some people might find them at least somewhat interesting and/or mildly amusing. I certainly love Bob's!
Maybe this CTC-120 thread is the jumpstart I need to actually turn the thing around and finally DO something about it!
The thing has an awesome picture!