CTC 9 kenbridge
 

I'm finally starting work on my CTC 9 after having it for over a year. When I got it the main problem it had, was it would loose picture (go to a blank raster) and sound intermittently. It happened more frequently on higher frequency channels 7-13, than 2-6.

After a year, it would hardly hold the picture and sound for a few seconds, even on ch 2, and no color at all. The remote never worked, but to turn the volume down when I hit the channel button.

Today, I first pulled the osc tube in the tuner, and found a weak 6GH8 in there for the 6EA8, and a 6BZ7 replacing the 6BC8. After putting in a good 6EA8 one problem was solved and the picture and sound would stay put, but sound was weak and no color. After putting in a good 6BC8 I had good sound, and color, but the color sync won't hold, after a while I either get no color, or those multicolored horizontal bars moving down the screen. I'm hoping I can just fix that with adjustment.

I also found the crt socket is cracked and held together with tape, but I have a nice replacement one still in the original wrapping.

Strangely the original electrolytic cans are actually working fine, and not even heating up. But seeing as I'm pulling the chassis anyway I can't see not recapping, and just winding up having to pull the chassis again later.

Also, I found a sticker inside saying the CRT was replaced in 1961, I wonder what happened, I wouldn't have expected the 21CYP22 to have gone bad in 2 years?

It's very clean inside, with a whopping 33 tubes in total :yes:

My 1958 CTC 7 has a 21CYP with a 1961 date code so it probably wasn't all that uncommon to need a new CRT in two or three years, depending on how much it was used I suppose.

I'm guessing 10-20,000 hours was probably a reasonable lifespan for those early tubes.

Here's the sticker. It says:

[MOD]EL # 210CKR940
INSTALLED 3-23-59
KINESCOPE Replacement
21CYP22A
INSTALLED 1-5-61

Mine doesn't have a sticker but it has 61 in a circle on the end of the base cap, I'm pretty sure it's a date code.

I have a CTC-9C and it had the kinescope replaced in the early 60s as well. When I received the set, the guns had absolutely zero emission. It also had a brightener on it. I have stuffed the filter capacitors and put in a used 21CYP22 and it has a bright raster. I hope to get to it after May of 2013 so maybe we can compare notes. Good luck with the set.

I recapped the electrolytics (just mounting replacements under the chassis), and the few paper caps still that were still in this set. Next I'll change that CRT socket. Then run all the tubes through the tester, just to see if anything tests bad. (Which for the most part I'm not expecting, the only problem I'm having being the color and the remote). Then I'll do that chroma oscillator alignment which I expect will fix the color.

Then finally get to why the remote's not working. (I expect the problem is some mechanical issues with stuck gears, as well as bad tubes in the remote chassis, (because it is possible to have the remote chassis on, with the rest of the set off - I often find bad tubes in these, I expect people left TVs on like this for long periods of time) and maybe the remote receiver needs alignment as well) As much as I like the Zenith space commander sets, there's something more impressive about these RCAs where the remote actually turns the vol, tint, and color controls. It uses a single motor for everything with solenoids to switch which control it turns.

What is generally used to clean and lubricate the plastic gears? Some of them are sort of gummed up, I usually clean this sort of thing with lacquer thinner, but I wouldn't use it on anything plastic.

Well the only tube that tested weak in the whole set (other than those in the VHF tuner I mentioned before), was the audio output. I swapped it for a stronger one, but I wasn't having any troubles with the sound. The 21CYP22A tests good (between 600-700 on all 3 guns) There were no bad tubes in the remote chassis like I expected. A lot of the tubes in this set look original and test very good, with the exception of the the fact that this has a replacement CRT this looks like a very low hour set. That in combination with the cracked CRT socket it had makes me wonder if they didn't replace the tube because someone banged the set from the back and broke the neck of the tube.

And I put the new CRT socket in. But I spent most of the night fixing my tube tester (Sencore TC28). I expected the problem to be dirty switches, which I took all apart and cleaned, but it was several bad solder joints on a circuit board. I have an older Sylvania tester from the early 50s I usually use, but it doesn't give settings for many of the newer tube types in this set.

After alignment the remote is working somewhat. But ... the channel control, while it engages the motor, it doesn't actually move the tuner. The vol and tint only turn the controls up, no matter which way I push the button. (There is an additional single relay which is supposed to flip when the motor is supposed to go backwards for all the controls, which isn't working) And the color control flips its relay, but doesn't activate the motor at all.

I got the remote working completely. You can see the remote chassis, and the mechanical aspects of how the remote works in the pics.

The color control wasn't turning because there was some gunk jammed in the relay for that control. The other remaining problems were due to mechanical issues. Because the remote chassis has its own power supply, it's easy to work on the remote stuff with everything up on the bench.

No matter which button you push, the gears behind all the solenoids turn. But only one solenoid will engage, corresponding to the correct control. So with 4 functions on the remote, there's 4 circuits each tuned to a slightly different frequency (hence the need for alignment), corresponding to 4 separate relays (with 2 additional relays to turn on the motor in either direction), and then 4 solenoids.

Good on ya!! Glad you got it all sorted out. Not many sets are out there with a remote.

The remote Zeniths seem to be more common that the RCAs...

I finally have color:banana:

I tried several (all testing good) 6EA8 chroma osc tubes, did the alignment, realignment, alignment with different tubes, resoldered the crystal a few times, and some other stuff, not quite sure what finally did it, I finally have no more moving color bars up and down the screen. I've had this same problem with every early color set I've ever had. With the exception of one CTC15 that I had that ate 6GH8s, once I got it to work it stayed working ... but what do you have to do to get these units to work properly? Take the chroma oscillator tubes out under a full moon, and recite the proper incantation over the tube while hopping on one foot and spinning counterclockwise 3 times!!:dunno::headscrat:scratch2::tongue::o:D

And I also crossed some wires I shouldn't and blew a fuse while I was messing with this, all I took out was a 1k resistor and the fuse, but the fuse has to be a weirdly shaped one I don't have :thumbsdn:(so it's just bypassed for now)

I'm going to eat lunch, then touch up the convergence a bit, then I'll take some pics...

pics...

Wow, that looks great!

damn!that a very colorful picture on that set.nice saturation.post more pics!

That looks great! Sooo jealous here!