Rca Ctc9

[David Roper]

Originally Posted by Einar72

you don't get that "is it gonna blow?" feeling when you turn it on.

If you know exactly when to turn it on it's less likely to blow, and even then you can always change the channel.

[blue_lateral]

[Ampico-kid]

Speaking of sets that are "going to blow", I'm wondering what the consensus is regarding cap replacement?

All of my restoration work so far has been on sets that are older than this CTC9 chassis and used paper caps. There was no question that all of the electrolytics and paper caps had to be changed. The CTC9 does have a number of electrolytics that will be changed, but it has no paper caps( a couple of black beauties though). Most of the caps it contains look like the predecessor of the "orange drop" type of caps and are a sort of dark chocolate brown in color.

My first inclination is to replace them all and be done with it. I don't like the idea of going through the entire set, doing all of the restoration work on it only to find that there are other problems relating to leaking or open caps and have to yank it out of the cabinet umpteen times trying to troubleshoot it. But there are two potential problems with that scenario....first there's always the possibility that a cap could be installed wrong or something around it could be disturbed or damaged in the process. And number two is that some of these caps have very strange values. The replacements might not be close enough to the original value.

What's the general consensus about cap replacement?

Thanks!
Bob.

[jpdylon]

At the very least you should replace the lytics' and the black beauties. The future life of the set depends on it. The brown drop lookin things are i believe mylar film caps and usually never die. I would leave those in unless you find problems associated with their circuits.

That's a great set you brought home. I'm jealous.

[Ampico-kid]

Hey Jordan;

Thanks for the advice. Leaving the original "Brown Drop" caps alone was what I had in mind, but I guess I wanted to hear someone else say it. I was a little apprehensive about leaving them in place when I did the restoration, just force of habit I guess, since most of my experiences have been with much older equipment and usually contain lots of paper caps and dripping wax.

I've already ordered the electrolytics and some replacement tubes. I'm waiting for the schematic to arrive to check the value of the two "Black Beauties" in the chassis. Surprisingly all of the tubes in this set were still the originals, except for the horzontal output. And even at that I've only found a handful (about 6) that need replacement.

Seems like the biggest mess so far has been trying to clean some of the "ooze" off of the wires running from the chassis up to the CRT socket. I guess there is some sort of a chemical break down going on there and the result is this sticky, gunky, slime all over the wires which in turn picks up and holds all of the dirt and grime from the air around them. I'm making progress cleaning it up, but it's not a very pretty picture right now.

Bob.

[compucat]

Originally Posted by Ampico-kid

Hey Jordan;


Seems like the biggest mess so far has been trying to clean some of the "ooze" off of the wires running from the chassis up to the CRT socket. I guess there is some sort of a chemical break down going on there and the result is this sticky, gunky, slime all over the wires which in turn picks up and holds all of the dirt and grime from the air around them. I'm making progress cleaning it up, but it's not a very pretty picture right now.

Bob.

You will find that stuff on many old tv sets. I think it is some kind of coating on the insulation of the wires that gets a little sticky and attracts the dust. I find cleaning the outside of the wires with mineral spirits will disolve that gunk away and leave a clean undamaged wire. I hate that sticky stuff, it makes a restoration look incomplete if it's not removed. I just finished a Philco radio that had that on the audio output transformer wires.

[Einar72]

Originally Posted by Ampico-kid

I've already ordered the electrolytics and some replacement tubes. I'm waiting for the schematic to arrive to check the value of the two "Black Beauties" in the chassis.

Since that chassis uses a solid-state rectifier pair (selenium, I think), it would be wise to make sure all the new electrolytics are "formed", before you install them. Simply put, their electro-chemical properties are optimized for proper function. Even "new" caps can blow chunks if slammed with full working voltage. It's not hard to do, and you need more patience than anything else, but it's worth the trouble.There is an excellent thread somewhere in here on the process.

[andy]

---

[Ampico-kid]

Originally Posted by Einar72

Since that chassis uses a solid-state rectifier pair (selenium, I think), it would be wise to make sure all the new electrolytics are "formed", before you install them.

Thanks for the tip. I've already looked up the thread discussing that subject and will be sure to go through the proper procedure before I "fire it up".

And as for the defective "orange drop" caps, I fully understand what you're saying. At this point I'm going to do the basics and see what I have once I get it up and running. If need be I can always go back and start replacing them.

Thanks.
Bob.

[Ampico-kid]

Hi;

Just finished the preliminary restoration work on the CTC 9 chassis. Replaced all of the electrolytics, black beauties, off value resistors, weak tubes, and gave it a general sprucing up. I spent a good part of yesterday "forming" the electrolytics and decided that today it's time to see if it works.

I put the chassis back into the set, reconnected all the proper wires and turned it on. Within about a minute I had a pretty dim picture and found that the horizontal control was set way off in left field. After I adjusted the control back to it's proper position, degaussed the front of the picture tube, played with the purity a little bit and then hooked up the dot bar generator, the attached picture is what I had. All things considered I think it looks pretty respectable for it's first "check up".

Some of the controls are a bit "dirty", and the convergance definitely needs to be gone over, but I didn't see any real serious problems. The only malfunction I found is the fact that the red level is too high. Even with the red background control at minimum there is still some red evident in the picture. The green and blue when turned fully counter clockwise will not be visible at all, the red will still be visible. It's not real bright, but has enough luminance to be visible. In order to get something even close to a black and white picture the red must be at minimum and the other two controls close to max. I checked the picture tube on my tester and all three guns seem pretty close in output. Not sure yet what the problem is, so I've got to do a little detective work on that one.


Just thought you'd all like to see what progress has been made.

Thanks!
Bob.

[Bill R]

If you can get a good black & white picture by adjusting the blue and green screen and background controls I wouldn't worry to much. The procedure in the field service guide calls for the red control to be 1/4 turn up from ninimum anyway. Then you use the red and green screen controls to get a good b&w picture through the brightness range without blooming. Remember red was one of the least efficient phosphors used. The red control is not to be changed from it's initial setting. On later sets they added a Kine bias control that you would trun down until the dominant color just dissipeared. If red is indeed to high to get a good gray scale, you could check the resistors in the crt bias ciriuits. It is possible you may have a resistor that has drifted off value.

Bill R

[Ampico-kid]

Hi Bill;

Thanks for the information. I'm going to do a some additional work on the chassis and will check the CRT bias resistors. I'm not sure about getting a good black and white picture yet. I'll have a better idea once I iron out a few other "bugs" in the system.

I'll keep you posted.

Bob.

[Ampico-kid]

Hi;
It's been a while since my last post, but I've been busy working the bugs out of this RCA CTC9 chassis. The last kink was ironed out today and I finished the convergence for what turned out to be a triumphant finale to a relatively troublefree rebuild.

I'm quite amazed at the quality of the color picture on this set. I've attached several photos so you can see for yourself the beautiful color renderings this almost 50 year old Color TV is capable of producing.

My main concern when I first picked up the set was the condition of the picture tube, but that turned out to be an unfounded fear, obviously the tube has plenty of life left in it.

What do you all think?

Bob

[jpdylon]

Awesome pictures.

I'm not sure if its just the camera or the set, but it seems a little saturated and the flesh tones are a bit on the purple side.

I am glad you were able to bring the set back to life. I dream of owning a CTC 5, 7 ,or 9 someday.

[Adam]

That looks good, I'm hoping my 10 look will like that when I get to it.