Ctc-7aa

[Daave]

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.

[Phil Nelson]

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

[IsthmusTV]

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

[bgadow]

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!

[Eric H]

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.

[Ampico-kid]

Originally Posted by Eric H

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

[miniman82]

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

[IsthmusTV]

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

[ChrisW6ATV]

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.

[IsthmusTV]

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.)

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:




Here's one obvious hack repair:


The fly has some melted wax but overall looks pretty good:


I discovered that main fuse had blown, and someone used a piece of tinsel to jump it At least it would have offered some protection:


There were over thirty boxed tubes included with the set, many NOS including 2 6DQ5s. Unfortunately, the one NOS 6BK4 had gone to air:


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

[Phil Nelson]

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

[leadlike]

My CTC-9 uses a glass envelope color crystal.

[IsthmusTV]

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

[kvflyer]

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.

[mstaton]

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.