View Full Version : CTC20 possible project


Arcanine
10-21-2015, 08:01 PM
Okay so, the guy I bought the CTC16 from, had no idea it was bad, and felt bad so he gave me a complete CTC20, disassembled, with the cataract removed from the CRT, but complete.

I'm strongly debating reassembling it. I have a cataract to go with the CRT, and it's a nice metal cabinet roundy, and it even came with the legs. So it can be a table set, or it can be a stand alone.

Only issue; this.

http://img.photobucket.com/albums/v480/RileyWestwolf/coil_zps1kabynga.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/coil_zps1kabynga.jpg.html)

I need these two coils. One is not as bad as the other, but both are busted... The guy was careless with the chassis and the tuner was sitting ontop of it, and snapped these off.

What are each one? The one laying down, and the one that's half broke off. Can these still be found and does someone maybe have these spare?

Kamakiri
10-21-2015, 08:40 PM
If it's a CTC-20, it's not a roundie. The last roundie was the CTC-16. You sure that's the right chassis? :)

rca2000
10-21-2015, 08:59 PM
I am pretty sure you are MISTAKEN. I DO think the CTC-20 IS a roundie---the "last gasp roundie', from 1967. A LOT like the CTC-16 BUT the chassis is more of a CTC-19 "beefed up" to run a 21FJ tube.

Arcanine
10-21-2015, 09:07 PM
If it's a CTC-20, it's not a roundie. The last roundie was the CTC-16. You sure that's the right chassis? :)

Yeah. It says right on the Chassis, CTC20. Like has been said in other threads it's the last RCA Roundy. Only has two boards on the chassis.

I'd like to make it a viable project.

Electronic M
10-21-2015, 09:07 PM
If all the leads exiting the windings are intact, and did NOT break off inside the windings, then they can be CAREFULLY soldered to phono pickup wire and reattached to the base lugs......I've done this before....3-4 years ago I forgot to unplug the CRT socket before pulling the chassis on my Silvertone CTC-15 clone, and they hoked and ripped the chroma osc transformer coil clean off. All the leads broke at points where I could tack new leads on to them, so I did that and glued the form back into it's base. Not the most elegant solution, but it works fine.

Arcanine
10-21-2015, 09:18 PM
If all the leads exiting the windings are intact, and did NOT break off inside the windings, then they can be CAREFULLY soldered to phono pickup wire and reattached to the base lugs......I've done this before....3-4 years ago I forgot to unplug the CRT socket before pulling the chassis on my Silvertone CTC-15 clone, and they hoked and ripped the chroma osc transformer coil clean off. All the leads broke at points where I could tack new leads on to them, so I did that and glued the form back into it's base. Not the most elegant solution, but it works fine.

All the leads are there, looks like they broke off at the solder, not up at the coil. I don't think I have that level of skill to do that.

Electronic M
10-21-2015, 09:30 PM
All the leads are there, looks like they broke off at the solder, not up at the coil. I don't think I have that level of skill to do that.
Luck is probably on that chassis' side then. It is likely going to be necessary to have a schematic for it to verify winding connection points. It is always a sweat inducing process soldering tiny wires like that....First time I tried I was like 14-16 and was working with a 1/16" stub protruding from a H osc coil on a GE portable. I was having a hell of a time getting it to stick....Then mom interrupted me at the wrong time and caused me to accidentally rip out the lead I had.....Boy was I livid after she did that. My hands are steadier now, and I've gotten better at soldering.

Arcanine
10-21-2015, 09:53 PM
Luck is probably on that chassis' side then. It is likely going to be necessary to have a schematic for it to verify winding connection points. It is always a sweat inducing process soldering tiny wires like that....First time I tried I was like 14-16 and was working with a 1/16" stub protruding from a H osc coil on a GE portable. I was having a hell of a time getting it to stick....Then mom interrupted me at the wrong time and caused me to accidentally rip out the lead I had.....Boy was I livid after she did that. My hands are steadier now, and I've gotten better at soldering.

YEAH. That'll be your baby... My hands are not steady enough anymore. Wrenched on cars too long, I don't have the best fine motor skills anymore.

old_coot88
10-21-2015, 10:27 PM
I am pretty sure you are MISTAKEN. I DO think the CTC-20 IS a roundie---the "last gasp roundie', from 1967. A bit like the CTC-16 BUT the chassis is more of a CTC-19 "beefed up" to run a 21FJ tube.
That is correct. It's a roundie. And it's a turkey. We sold several of them. They had weak vert sync right outa the box. The factory was kind enuff to issue a mod consisting of changing the values of two resistors in the sync separator circuit to improve it. They were half-watters of something like 270K and 680K, IIRC. Later runs of the chassis may (or may not) have the mod already done.
All the '20s I ever seen had lousy vert linearity even after the mod. Very hard to get decent ht. and lin. balance.
Caveat emptor.

old_coot88
10-21-2015, 10:33 PM
FWIF, here's a tip for stripping hair-fine wires for soldering. Scroll down to post# 26..
http://videokarma.org/showthread.php?t=257295&page=2&highlight=aspirin