Ctc-7aa
 

Greetings,

I have been in on and off negotiations with a local collector (mainly vintage hi-fi) to buy his RCA CTC-7A roundie set. Today, I got a chance to look it over for the first time. It's in a cramped, dimly lit storage room with barely enough room to turn around. I took a few lousy photos with a flashlight and my cell phone which are posted below. It's unusual in that it's in a tabletop steel cabinet with a fake wood grain photo finish. The chassis is stamped CTC-7AA. I couldn't find the model number. The back is missing (he thinks he may have it somewhere) and the cabinet is filled with boxed tubes and what looked like the SAMS for the set. My visit was unplanned, so I didn't have my CRT tester with me so I don't know the status of the 21CYP22 which appears to be original.

Of course, now that I get to see it he's having second thoughts about selling it because "these are going to be worth a lot some day" :sigh:
Still, I think he may come to his senses and sell it to me. This would be my first color roundie, so I'm keeping my fingers crossed.

-Clark

how much was that camera that takes old 1940's Alfred Hitchcock murder mystery movie pictures? And where can I get one?

I have one of those metal cabinet CTC-7's but its in much worse shape than what you have there. My CRT one open filament (too bad as the others tested very well). hope you get it.

Offer him $200, see if he pops for it.

Doncha jes LOVE IT when sellers start gettin' "Cold Feet" ?!?

I believe the CTC-7AA is the late production Abington 21-CD-872-5,
Mahogany Grain Finish CTC7AA, 1958. Hope you can shed some real light on this set and get the owner to part with it. If he does, have him do a search for the back.

-Steve D.

Yah, cash talks. But I wouldn't phone him back right away. which only reinforces his idea that it's a treasure.

If you know it's been sitting there quite a while, wait at least a week, maybe two, and then show up with cash in hand and a big smile on your face.

Phil Nelson

It could also be the 21CD8712 Meredith. Source: RCA field service guide.
Phil, the last thing I would do is to go in with cash in hand and a big smile. I'd say here is my cash money offer, take it or leave it, and give him my phone number if he doesn't bite. If he has a wife flash the cash around her.
IsthmusTV, good luck.
Phil

Thanks for all the feedback. I've known this guy for years and the set has been there a very long time. I'll wait a few weeks and see what happens. He said that he might be interested in a trade. Of course, what he's mainly interested in is tube-type hi fi gear of which I have none. I think showing up with the cash may be a good strategy.

What I'd really like is to be able to test the CRT. If it's shot, I think I would walk away or make him a low ball offer.

Stay tuned!

-Clark

This set looks to be in nice condition. The painted woodgrain cabinets seem very durable as long as they're kept out of damp storage areas.

I do think the best way to get this TV, would be to show up with a tube hi-fi, or some juicy audio tubes. So keep your eyes open for those items, and then show up and offer to trade.

If I did not love the cabinet styling of my 65' philco roundy I'd offer it to you.

Hi Tom,

Thanks for the thought. Since we're so close distance wise, I'm sure that we'll exchange something along I 94 one of these days :thmbsp:

My guess is that I will eventually procure the CTC-7 from this guy.

-Clark

Well, I got my Christmas present early-- I got my first color roundie :banana: Yesterday, I got a call from the HI-FI dealer asking if I still wanted the set. He said he needed the room, and that I had to take it "as is" but for $100. I said, sure! Turns out that he just got another RCA roundie, also in a metal cabinet, but this one has the blond paint job. I saw it in the back of a freight elevator but I couldn't get close enough to ID it.

So, I was able to test the 21CYP22 before taking it and it woke right up with good emissions from all three guns:banana: It came with many NOS tubes and the RCA service manual. So far, he has not found the back. It is now home sitting on my dining room table. Things look pretty good overall, but I did find one troubling thing: A large quantity of grayish-white goo has oozed out of the power transformer (see photos). It's weird, I've never seen this color substance come out of a PTX before. It's still quite runny, more like grease than tar. Anyone seen this before? Seller thinks it was stored in hot conditions at some point. So, one of the first things to check is the health of the transformer.

I'll pull the chassis this weekend and post some more photos soon. I'm glad that I waited him out!

-Clark

Here's another shot of the goo accumulated at the bottom of the cabinet.

Great to see another one saved from destruction!:banana: I'm going to start on the second restoration of my blonde Anderson CTC-7B after the holidays. It's my first rounde that was bought after my stint in the Army in 1971. :D

Thats cool. I originally wanted a pre-1960 roundie as my first but living in this country it was never gonna happen unless I imported it.

Yes, a very small amount of gray stuff had come out of the power transformer on my CTC-7. Cleaned up pretty easily with something like mineral spirits.

I would definitely check out that transformer, and withhold judgement in the meantime. Mine seems fine; I replaced the electrolytics before applying power, of course.

Even if that transformer has fried, a CTC-7 with usable CRT is a good buy for $100. Congrats!

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Thanks, Phil. I've read your account of your CTC-7 on your website and it was very informative as usual. I think I'll try your technique of cutting the EC cans right on the chassis. I'm keeping my fingers crossed about the transformer. I'm glad I'll have some time over the holidays to start working on it!

-Clark

I have a NOS transformer for a CTC-15 that spent the last 40+ years in a hot attic. It seems to have "sweated out" something similiar to that.

Great find...great Hallicrafters clock, too!

My 7 also has that gunk leaking out of the transformer, it works fine though.
I think it just creeps like a Glacier over 50 years time and starts to drip.

I'll say ditto to that. My 7 also had that gray gunk running down the chassis. Used some mineral spirits to clean if off. The set has been running fine after an electrolytic recap. Bob

You should see the stuff inside the PTX, I unbolted the top cover on mine to have a look... NASTY!

Thanks for all the replies. That's very reassuring to hear that the goo doesn't mean that the transformer is fried. I'll use mineral spirits to clean it up. My plan is to recap the power supply and then do a brief power up before replacing any more caps.

My cat, Gilda, definitely approves of the new acquisition. The jury's still out on the rest of the family!

-Clark

Could that goo be some type of coolant, similar to what PCBs were used for in power-line transformers? (I sure hope the RCA stuff is itself not a variant of PCBs.) If it is for cooling, the minor loss seen in the pictures (and described by others here) should not affect occasional short-term use by a collector, in my opinion.

I wondered about PCB content, too. I'll treat it with due caution while cleaning it up.

I had a very busy weekend but I did find time to pull the chassis and give it a quick once-over. It's very clean, with minimal signs of past repairs. The date stamped on the delay line is August 13, 1958:
http://i1216.photobucket.com/albums/...V/P1020368.jpg

http://i1216.photobucket.com/albums/...V/P1020365.jpg

Here's one obvious hack repair:
http://i1216.photobucket.com/albums/...V/P1020366.jpg

The fly has some melted wax but overall looks pretty good:
http://i1216.photobucket.com/albums/...V/P1020369.jpg

I discovered that main fuse had blown, and someone used a piece of tinsel to jump it :nono: At least it would have offered some protection:
http://i1216.photobucket.com/albums/...V/P1020373.jpg

There were over thirty boxed tubes included with the set, many NOS including 2 6DQ5s. Unfortunately, the one NOS 6BK4 had gone to air:
http://i1216.photobucket.com/albums/...V/P1020371.jpg

Time to get a list of caps together. I hope to replace the electrolytics in the PS over the holidays and try a brief power up.

-Clark

Looks pretty good, overall.

I wonder if that tinfoil fuse had anything to do with the ocean of transformer goo?

I see that yours has a color crystal with flat metal envelope. My crystal is in a round glass envelope similar to a mini tube. Something I hadn't seen before, and I have both earlier and later RCA color sets that use the metal envelope. Perhaps mine is a replacement, or RCA was just using what was available at the moment. . . ?

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

http://antiqueradio.org/art/RCACTC-7Crystal.jpg

My CTC-9 uses a glass envelope color crystal.

Hi Phil,

I thought the same thing about the fuse. I REALLY hope that the power transformer is OK.

That's interesting about the crystal. I haven't seen the glass style used in a TV either. I would think that it might be superior to the metal type, at least in terms of its resistance to moisture.

-Clark

Looks like someone converted the power fuse to a "No-Blo" type. My CTC-9 had the same type of fuse. They are more difficult to find than the regular 3AG type so I changed the fuse holder. Now, I can still use the correct value fuse and it is much easier to find. I am not that much a purist to make this change.

That shunt regulator(?) appears to have gone to air.

Nice clean chassis! Just use a soft brush and some canned air on the PCB boards. Don't go overboard on those since they are easily cracked, especially those dark ones.

Hi Guys,

Yes, I think I'll just change the fuse holder to a more standard type instead of continuing to use the oddball ones (and certainly not the "no-blo" fuse it came with, LOL)!

I'll be careful when cleaning. Fortunately, this one doesn't have greasy kitchen grime or nicotine deposits.

In addition to the boxed tubes, it came with an original RCA service manual that is correct for the chassis complete with a fold out schematic. It's a little beat up, but usable. It contains notes from a TV repair shop with a previous owner's name dated 2002. So someone has been poking around in this thing fairly recently.

-Clark

BTW, I apologize for not congratulating you on finding and saving this piece of history. Glad that you have it in your hands. It is much cleaner than the CTC-9 that I have as mentioned above. Mine came with a booster on the picture tube. All three guns registered zero emission even when the filaments were cooked on 8 volts for about 30 minutes. Luckily I had a used CRT for it that was very good. I gutted the three electrolytic capacitors and stuffed them, brought it up on a variac with a Kill-A-Watt in series with it and got a raster. So, I know all of the major components are good. Please keep us posted...

Thanks, kvflyer. The is the one and only color roundie that I've been able to locate around here after months of looking. I'm going to take my time and try to do things right. I just placed a cap order with Mouser so that I'll have what I need to re-stuff the power supply electrolytics. I'm keeping my fingers crossed about the power transformer. I hope to have some time to work on this over the holidays.

Merry Christmas and Happy Hanukkah

-Clark

Congrats Isthmus!:banana:
I'm redoing a 7AH console with remote control,..mine had a BAD power tranny from a lighting strike from many years from the 1st owner leaving it plugged in during
a Thunderclap..got mine for $20 bucks 2 years ago at a estate sale locally nobody wanted it...its in great shape also all over except..having a blown tranny
got a new one from Moyers..last one they had on the self...found the thermo-switch is bad also..wonder how you would replace that?:scratch2::scratch2:

I did find some time this week to work on the chassis. It had been sitting on my workbench in a horizontal position for four or five days undisturbed. When I lifted the chassis, I discovered that a big blob of transformer goo had collected:
http://i1216.photobucket.com/albums/...masCTC7024.jpg
http://i1216.photobucket.com/albums/...masCTC7025.jpg

Apparently, being horizontal got it flowing in new directions. Keep in mind, that I still haven't applied power and that the temperature in my workshop is about 60 degrees. This is a pretty large quantity of stuff. Is it possible that some sort of internal seal broke allowing this stuff to flow? Here's a shot after I scraped it off the carpet square with a penny for size reference:
http://i1216.photobucket.com/albums/...masCTC7026.jpg

On other fronts, I replaced the kluge repair with a proper resistor. I also found a charred 5600 Ohm resistor feeding the plate of the 12AZ7 color demodulator. It measured 144 Ohms! I wanted to find what had caused this overload. The 12AZ7 measured a bad HK short. In addition to the tube and resistors, I replaced a couple suspect caps in the vicinity:
http://i1216.photobucket.com/albums/...masCTC7027.jpg

I did use Phil's approach to the PS electrolytics. It all went pretty smoothly:
http://i1216.photobucket.com/albums/...masCTC7033.jpg

I also added a standard fuse holder, leaving the old one on place:
http://i1216.photobucket.com/albums/...masCTC7036.jpg

Two of the cans were definitely toast! I didn't even need heat to pull out the innards:
http://i1216.photobucket.com/albums/...masCTC7034.jpg

I ran out of time for now. I'll finished the third cap this weekend and attempt a first power up. BTW, all the windings on the power transformer look OK with an Ohm meter so I'm still reasonably optimistic that it will be OK.

-Clark

It's alive! I finished changing the PS electrolytics and did a first power up. At about 85 Volts, I heard the thermal relay close and the HV spooling up and saw the first raster :banana:
http://i1216.photobucket.com/albums/...V/P1020404.jpg

I added a signal source and got this at about 100 Volts. The audio was excellent:
http://i1216.photobucket.com/albums/...V/P1020405.jpg

At 117 Volts, it was drawing 2.25 Amps with no sparks, smoke or bad noises. The horizontal was close but wouldn't lock:
http://i1216.photobucket.com/albums/...V/P1020407.jpg

The picture was nice and bright with good focus. I'm very relieved that the oozing power transformer is OK! It didn't get even warm to the touch after about 20 minutes. It even looked like the color locked for a while.

So a lot seems to be working well with this set. I'm going to recap the horizontal and vertical boards first and go from there. When I pulled the chassis, there were no signs of overheating anywhere, including where I replaced those resistors and caps. A nice start to the new year!

Happy New Year to all.

-Clark

Since you recapped it the horizontal frequency is probably off, tweak the slug on the board to get it back and you should have a watchable picture!

What I wrote wasn't very clear. At this point I've only recapped the electrolytic cans in the power supply. I'm preparing to recap the horizontal board now. I tried adjusting the frequency throughout its range and it won't lock. This is exactly what Phil Nelson experienced with his CTC-7. The horizontal wouldn't lock until he got rid of the maroon drops on the horizontal board.

I hope to have a watchable picture by tomorrow!

That absolutely makes sense. Unfortunately, it seems that almost every vintage capacitor is now leaky. And since the Horizontal will not lock, there must be a capacitor issue in the horiz section. Looking forward to the picture of the locked image on the CRT.

can you flop the horz lines? or will it just go one way like its out of range of adj?