Any information on a RCA CTC-39VA - Videokarma.org TV - Video

Phil R · #1 01-22-2015, 11:56 PM

I just got this TV because I liked the simple cabinet. I assume it's from around 1972-73 but I have no way to tell... I haven't tried to connect it yet as it was stored in a cold place but I'd be surprised if it works.

I don't have electronic skills or equipment but I'd appreciate if I could get some advice before I attempt to connect it! The previous owner told me he got that with a house he bought and he also told me he connected it. And that it "worked" as he could hear sound and see the picture tube showing snow but I didn't trust that.

The power cord was cut and his son had just attached a new cord to it and was ready to test it at 10°F! I told them not to try it, that i'd take it anyway at a lesser price as I was pretty sure at this point there was something wrong with it! I removed every screw that was holding the back panel by hand so someone has been there and for some reason, didn't fasten the retaining screws as if the repair job wasn't done!

I heard that some RCA chassis from this period (or maybe a bit older) weren't too good and had a lot of flyback problems. Is this one among them?

Phil R · #2 01-22-2015, 11:58 PM

A few more pics...

Phil R · #3 01-23-2015, 01:24 AM

I plugged it and I do get sound and snow as the seller told me (I really didn't expected that!).

But the image won't stabilize on channels 3 or 4 with the converter box. I'm not too familiar with the controls and adjustments on this TV.

I wish I had more technical knowledge but I think I'll need some help with this!!

There's a screw to adjust each of the VHF pushbuttons and there are 4 UHF presets that can be tuned by small knobs hidden behind the panel. There's another control which says "fine tuning pull" below that door and it can be pushed for "accutouch". What's that, I don't know!

Phil R · #4 01-23-2015, 04:01 AM

Here some larger pics.

https://www.flickr.com/photos/337230...h/16345745712/

zeno · #5 01-23-2015, 06:32 AM

Never seen one. Looks like an updated & common CTC38.
On CRT the 72-52 means 1972, 52nd month so set was built early
1973.
For tuning I will give you the most likely process, maybe
one of the RCA pros knows for sure.

Hook up box.
Press ch 2 button
Turn off any controls marked auto or accu.
Now the ch 2 control should tune from ch2-ch6 or ch2-ch13.
Usually ch 2 will be almost full CCW. Tune the knob CW till
you see a color picture. The knob can be turned many times.
The meter is marked for UHF but should also read VHF, you
can watch that to see how you are doing.

You are off to a good start, the CRT looks very strong.
Good luck

73 Zeno

sampson159 · #6 01-23-2015, 08:33 AM

i had this same set about 25 years ago.very good performer with a top of the line rca crt.was a watcher for a couple of years and worked flawlessly.the tuner was a little touchy but once i got it set,it was fine.your crt looks bright.that one will take many hits if needed.good score and this is a fairly rare set

Electronic M · #7 01-23-2015, 09:23 AM

I'm surprised that you are so surprised that it works. I've had early 50's TVs that have not been repaired since the late 60's, and not powered on for over a decade wake right up and work, and I sort of expect most 1965 and newer sets to work, or come very close.

See what you can do with the fine tuning as a first step.

Phil R · #8 01-23-2015, 01:52 PM

I connected a DVD player to it and I was able to get sound. It also displays an image but not too good! No color most of the time and when it does...

I also noticed that the contrast knob doesn't turn...

That's the best I can do for now.

zeno · #9 01-23-2015, 02:26 PM

Horz phase is off & tint looks all the way to the green.
That may be one problem or two different problems.
Contrast probably needs a drop of WD40 on the shaft.
If you dont know TV already its time to do some learning
& get a sleeve of 6GH8's !
Not to worry, we all will help.

73 Zeno

Electronic M · #10 01-23-2015, 02:49 PM

A SMPTE color bar pattern will show tint misadjustment, and is a good calibration reference. You can probably burn such a pattern to DVD without much issue.

old_coot88 · #11 01-23-2015, 07:22 PM

If the set uses a 3-legged dual diode for horiz phasing, that is the most likely suspect.

Does the tint control have any affect at all on that 'greenish' component of the pic? If not, turn the color control all the way up & down, and see if it varies amplitude of the greenish component. If so, that suggests the 3.58 oscillator is not running (the greenish component being chroma information minus the 3.58 reference signal). Try wiggling all the tubes in their sockets on the chroma board. Corrosion in tube sockets often causes all kindza problems. Then test or sub the 3.58 osc tube.

Phil R · #12 01-24-2015, 07:58 PM

Where exactly is that 3 legged diode? is it welded to the board? The horizontal adjustment certainly has a problem... The Horizontal Hold is very sensitive and won't center the image...

Look at the image from the video. The color goes out as soon as the tuner is set for a clear image (if the Accutouch control is pushed, the image stays in black and white...).

I turned the tint knob while the recording this video. It does affect the colors but they can't be set correctly...

http://youtu.be/5YwrNCDaZ4M

old_coot88 · #13 01-24-2015, 08:27 PM

OK, the 3.58 osc ('color oscillator') is running but out of sync.
The 3-legged diode, if used, will be close to the H oscillator. But try adjusting the AGC first, if you haven't already. Have you tested/subbed any tubes yet (with emphasis on the sync and AGC tubes)?

Jeffhs · #14 01-24-2015, 09:02 PM

Once you get this TV working as it should, it should serve you well, as this is one of the original RCA sets from the '70s. You will still be able to use the VHF and UHF tuners, as Canadian TV, albeit mostly digital since last year, still has many analog channels still operating, unlike here in the US, where analog was done away with in 2009. I don't know what Canada's future plans are, if any, as far as "repacking" the TV spectrum are concerned (as our FCC is doing in the US), but until or unless they do follow our lead and eventually go 100 percent digital, you can use your RCA CTC-38 just as it is; just connect an antenna and enjoy it, just as you did before some Canadian stations went digital.

Phil R · #15 01-24-2015, 09:03 PM

I don't have any testing equipment. (other than a multimeter!). I wish I had the schematics but I couldn't find that exact chassis model on SAMS photofact. Most CTC-39 chassis seem to have an "X" after the "39", mine has a "V" instead (at least, that's what's clearly stamped on the flyback cover).

Maybe I don't need the exact model but...

I'm really not familiar with TV sets. I haven't touched to the AGC, I have located the control at the back but I don't even know what it is for (I know it means "automatic gain control" but I don't know what that means!). I don't want to sound stupid but I'm really missing some basic understanding and I can't find the most basic information on internet! I have seen videos of people rejuvenating picture tubes, making adjustments, testing the high voltage but I was missing the more basic things... I wish there would be detailed explanations on how to service old TV sets on internet but I haven't found anything for people who also need to get the basic knowledge. The most complicated electronic job I have done so far was replacing 3 capacitors in two microwave ovens which had display problems... That fixed the problem but I went from instructions that I found online, not from my own diagnostic!

I don't even know what the service switch is for at the back of the TV! I noticed it has 3 positions but I didn't try anything that I don't understand by fear of causing other problems... I also have been electrocuted when playing with an old tube radio when I was a kid and I'm careful not to touch anything in TV set. I don't even know what has the potential to shock you! I know most users of this forum are experienced but I'm not! I'm fascinated by these TV sets since I was a kid but couldn't ever find somebody to explain me how they work in detail!

Yesterday, I went to the only place in town that repairs electronics. I went there years ago with my Pioneer SX 800 receiver and when the guy noticed it had tubes in, he told me he couldn't service it... I guess he knows how but he's not interested at all. I just asked about the TV and I got the same answer... Needless to say there's not a lot of action in this store, as people don't care about having newer stuff repaired anymore!