RCA CTC-28A Restoration To Begin
 

In 1967, my parents got their first color television. It is an RCA "Tonsberg" CTC-28A set. I still have that set and intend to restore it. I know that Dad replaced the flyback many years ago. Also, the original 25XP22 is very weak. I have an NOS Channel Master 25AP22 rebuilt CRT.

In the picture of the set, you can see that the original RCA CRT has a severe cataract condition. Also, the Channel Master tube that I have is suffering the same issue; cataract.

I plan to get the set up and running before attempting to change the CRT. My main question is about the Channel Master jug. Has anyone removed the safety screen on one of these? Is the process the same as with Zenith and RCA? I live in Florida and putting it out into the hot sun is not a problem. Just wondering if the Channel Master is similar. I have already removed the clear tape around the circumference of the replacement.

Any insight and/or advice would be welcomed before I start.

Side note, after getting the set working, would it be advisable to practice on the original 25XP22 CRT first?

Thanks in advance.

Side note, on Wednesday, I go in for Cataract surgery myself. Not looking forward to it but just about every one of my friends has had it done already. I just hope they don't stick my arse out in the sun and poke clothes pins under the lense.:D

The sales brochure.

I've done a number of cataract removals on TVs. RCA type cataracts look white and or black and moldy (as in both your pictures) Zenith turn yellow-green at the edges... I've seen RCA tubes with Zenith style glue and Zeniths with RCA style glue...I've also had Philcos that were somewhere in-between. The best process is different between the types.... Zenith uses soft glue which is best cut with guitar string at room temperature in shade (heat can help but isn't anl necessity).
RCA is either heat and clothes pins or water (never had luck with water). Sun is best, up in Wisconsin I often have to grab a heat gun as a helper (the glue needs to be around 160f to let go) if you use anything other than even direct sunlight have an IR thermometer on hand and scan all around the face (you want to avoid differential of 30f or more across the face or the face can crack says a voice of experience). You want to pry out some of the edge glue to give the clothes pins a place to go....be very careful doing this...If you crack the safety glass you're guaranteed to be chiseling off over half of it which is unpleasant and after doing it right 4 times over the years I recently was rushed while doing one and chipped the hell out of the CRT face by accident. I don't have a favorite glue removal tool everything I've tried either bends too much or is too brittle and ends off snapping off either on the first or third tube.
The one pictured in the TV is cataracted clean to center...The glue isn't holding it anymore, and if the tape isn't holding it either it'll probably fall off when you remove the tube from the set...at its most stubborn all you should have to do is cut the tape and lift it.
The tube out of the set that only has a little edge cataracting will be difficult and require heat and clothes pins.

Generally the worse a RCA cataract looks the easier it is to fix. The rectangular RCA tubes tend to be harder too... Granted that may be sampling bias. I've had at least one of almost every RCA roundy chassis, almost no RCA rectangulars.

Zenith style tubes are cake to do a cataract removal on as long as your stand doesn't tip over when the string snaps...

Has anyone had experience with a Channel Master CRT? I have not put the tube out into the sun yet. But we certainly have intense sun here!

Should I use a guitar string or just heat and see what happens?

Thanks very much. It would be great to get this Chanel Master tube done. It's new and tests NOS of course.

It usually doesn't matter what the brand name is on the tube. It matters what the cataract looks like.
If it's yellow-green and the outer glue is very soft to sticky runny goo you call it Zenith style and use a guitar string.
If it's white and or black discoloration and like hard plastic and or crumbly you call it RCA style and use heat and clothes pins.

If the glue isn't soft enough to cut with guitar string it won't come off with guitar string.
I have a couple of channel master tubes with RCA style cataracts but don't remember if I did a removal on one...I have this vague notion in my mind that I either did one or saw something about one that made me think they're more troublesome of an RCA style job than a normal RCA.

Have you tested the old 25XP22 tube to confirm the emissions and that it's not circuit related?

Yes, it has very, very little emission, especially the red gun and it too has severe cataract too, so that tube would also have to be done.

BTW, I just had the cataract removed from my left eye this morning; right eye next Wednesday. Déjà Vu !!!

Update (or rather no update!). My doctor has told me NO lifting of anything over 25 pounds. And I get the right eye done on September 4. Therefore, this project must be put on hold for a few weeks. I will let you guys know how it goes.

And as I mentioned above, the original 25XP22 has very poor emission and I remember it being very dim when we used it many years ago. I had tested the Channel Master 25AP22 and it measured an excellent NOS. So I think the plan is to get the set working (heck, it may still be working, but I have a Sencore PR57 to use with it on first power up before trouble shooting).

Good luck. Every so often I get sparkles in my left eye on a very hot day. But lately I'm trying to overcome a bout with rhabdo that I think I also got on a hot day!

My Doc told me not to lift any more than a 30 pack. Have a bad back....
My squaw had a cadillac removed & she loves it. In & out faster than
I could find a shady spot to wait. I got them too but have tremors so
have to go to hospital & get knocked out.:boring:
Good Luck
Zeno:smoke:

Thanks for the observations from you characters. So far, the left eye is doing very well. Next Wednesday, I get the right eye done. In the meantime, I put a Motorola VT-71 with a blonde cabinet on the bench. It has been worked on before. But I have another VT-71 in the mahogany cabinet that responded very well to a restoration. Very straight forward. I will start a thread in the appropriate forum.

Meanwhile, back at the ranch...

I want to get rid of the rhabdo thing I got. I once removed cataracts off two 14QP4 tubes from Conrac monitors. Went well. Did it in an outdoor shed on a hot afternoon. Helped it along with a heat gun wearing goggles.
The doc says it'll be another 3 weeks before I start feeling better.
Be careful out there. DON'T GET THE RHABDO!!! (I am not making this up.)

Thanks! I think the doctor is smarter than I am because that is what he does for a living! The set was purchased in 1967 by my Dad and delivered by a tractor-trailer in our small rowhouse neighborhood! It can wait a few more weeks. In the meantime, I put a Motorola VT-71 on the bench. It doesn't weigh as much and I have done one before.

:lurk: