This set is a clone of an RCA CTC-25 with some engineering improvements. It has an epoxy-encapsulated flyback, a 6BQ5 audio output tube, IC audio demod (like the CTC-25 but a DIP IC) and cooling fins on the power transformer.

It had no power when I got it and I found there was a splice joint where a power resistor was replaced that had no solder and there was a bad soldering job on the rectifier diodes. Fixing this got the power supply working (I think I will replace the electrolytics just to be safe although the original ones don't seem too bad).

The CRT socket was bad, no filament voltage to the CRT so I substituted one in from an XL-100 (will solder the joints later.) I used the CRT tester to do a clean and balance and gave it 7.5 volts on the filaments for a little while and the CRT tested pretty good then. It is made by GE (EIA code 188).

Also the focus rectifier tube was bad and the pins were oxidised resulting in low focus voltage even with a new tube. Some deoxit on the pins fixed that.

I still need to clear up a video peaking problem with intermittent changes in sharpness of text and the sound is not working at all yet.

The cabinet of this set is very cheap. Particle board, masonite, and plastic.

i have one of these which I pulled out of a house I tore down. It was sitting in the living room with a '66 Silvertone color set sitting beside it. I've done nothing to either set yet other than remove the backs to find that EVERY tube has been removed from both sets. IIRC this cabinet, though cheaply built, is heavy, isn't it?

wow that cabinet is hideous, but at least the chassis is well made, Nice fly.

wow that cabinet is hideous, but at least the chassis is well made, Nice fly.

The fly is a Thordarson replacement - the red label (partially hiden by the black tape) gives it away. I sold a ton of those in the 70's.

Cheers,

Thats a neat set Chad, it's quite unusual especially with the horizontal layout of the control panel. Unlike alot of other collectors, the hybrid of plastic/wood on the cabinets never really bothered me. I guess knowing whats on the inside is all that matters. While I was never a big fan of medeterranean cabinets, I do like them when they are complimented with the red speaker cloth like this one.

Thanks Doug, I do like the cabinet style but I feel bad that CM had started to cheap out on the construction...it seems like a lot of the cabinet elements are warping as there is just not all that good of structural integrity to the whole thing. I have another CM color set which is probably late 60's and the cabinet making seems so much more solid.

I wonder if the Thordarson flyback was spec'd as OEM by CM. All of the solder joints/wiring look factory. The repair job that this set had where the diodes and a power resistor were replaced was real fly-by-night, the soldering was very poorly done and some joints didn't even have solder, leading to no power. Either the flyback replacement and the power supply repair were done by two very different shops or the flyback was OEM.

This must have been at a time where CM was trying to cut costs like in the cabinet but the engineering side was still trying to make a superior quality product. I wonder when the last real CM-built chassis like this was made? It seems like maybe CM went from this tube-type chassis to the NEC solid state chassis with no real CM-built solid state chassis in between.

I read somewhere that CM dropped tubes in '72-'73. Every CM solid state set, up through the mid '80's, that I've seen had an NEC chassis. A few years ago, someone gave me a solid state 23" delta gun CRT '74 CM combo that was in a cabinet similar to yours. The TV chassis was built by NEC, the CRT was made by Westinghouse, the stereo chassis and speakers were some cheap made in Taiwan crap, and the record changer was a cheap Glenburn. The set had "instant on" and the CRT was toast. Given the other problems it had, I junked the set. The cabinet was very cheaply made and the whole thing was heavy as lead.

I don't have a problem with the older CM tube stuff; but, their solid state TV's were, IMHO, the most overpriced, overrated junk of anything out there.

I once saw a late '80's 19" CM TV/stereo combo with a goldstar TV chassis in it and some of the late '80's CM consoles were actually rebadged RCA/Thomson sets. I recently junked a '94 CM console that was a rebadged Zenith, all the way down to the dead Zenith CRT.

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old frank had a curtis mathes in the mid 70s.he bragged it up so went to see it.cheap woodgrain cabinet and the picture itself wasnt so good.it was a combo unit that was as big as his house.the stereo did sound really good though.he watched this load while a nice chromacolor sat idle in the living room.the cm caught fire after a year and wasnt covered by the warranty.the zenith was reactivated as the watcher.he used the cm as parts.i believe the crt was ge?really cheap made and bad performing set

Repaired many Cm/NEC's years ago. IIRC they had a hugh black flyback that was troublesome and vertical issues. We could get replacement boards out of Dallas CM for a long time. And yes, the particle board cabinets were HEAVY. I could always tell when a drink was left on them from the swelling. The worst one was from a house filled with animals. We had to clean the top of the cabinet with a brillo pad. CM refused any dud credit on those boards. Sticky and nasty but the customer wouldn't get rid of it!

I have an early 70's CM 19" table top set that's all tube and made by NEC, so the transition to NEC must have happened slightly before they went solid state.

C-M made their own solid state chassis for a while. They had aluminum frames and they were built in St. Kitts, BWI. The boards looked kinda Jappy, but they didn't resemble the NEC chassis.

We had one of those St.Kitts sets. Our neighbor bought it new (he was the type impressed by C-M stuff) and gave it to us as a second set when he upgraded in the mid-80s. I seem to recall it had an RCA crt (delta gun) and was actually a pretty good set, solidly built. I want to say the cabinet was metal. When the vertical started shrinking real bad I started tinkering with it and eventually parted it out.

If you were also a woodworker, how hard would it be to make your own custom cabinet? That way you could use whatever wood, finishes, larger speakers, etc.

Sorry to steer off topic, just thought I would throw it out there!

I did make my own cabinet for a Zenith 25" 4-tube hybrid set which had been left outdoors for years and the original cabinet had completely fallen apart. It certainly isn't a work of art, I just made it from 2X4s and plywood and then stained it, but it is functional.

I have been thinking about trying to reinforce the Curtis Mathes cabinet with some real wood framing to help it hold together better. I'm afraid to try and set anything like another TV on top of it as it just seems so rickety.

Just watched the video, that's got a nice picture! Looks to be a low mileage set. Is it going to be a daily driver?

That cabinet probably added $250 - $300 bucks to the price! Back then you were also buying a piece of furniture. Trust me, I was there!

Thanks for watching the video, I'm going to set up a TV viewing area in this room and bring in some more sets including the RCA CTC-16 round set which is in storage.
I have looked through old Sears and Wards catalogs and saw the huge difference in price in round color sets. The cheapest in an ebony finish metal cabinet is hundreds of dollars less than the most expensive. The only features it lacks of the most expensive set are a degausser and maybe an additional speaker.
I have one of these "cheapest" round sets and I think it looks very nice with the black metal finish, better than the some of the more "frou frou" sets.

good video, you are right that is a nice chassis. Interesting they used the
6BQ5 and not a 6AQ5. My predicta is like that, would not expect a 6BQ5 but that is what it has. did you just try a new tube for the audio?

I'm going to start by putting on the test adaptor into the 6BQ5 socket and checking the voltages...I don't think it's a tube-related problem but I will check it just to make sure. The rest of the audio circuit is solid state (IC and transistors). That is the only solid-state part of the set. I may just install a 6AV6 triode as a pre-amplifier and convert the audio input to external only if the IC circuitry is bad as it will always be used with an external audio/video input

Die spamming scum!!!:thmsdn:

You can help kill spammers by pressing the red outlined triangle in the upper right hand corner next to the post number. That triangle is the report post button for spam and the like. Now you should once more be "on the beam".

Yes, Mr. Electronic-M, perhaps my explosive & angry comment above was hastily posted. BTW 'On the Beam' --for the 80s fans it was a stellar Space Monkey song and album from 1985. (substitute 'atrocious' for 'stellar' if you don't enjoy 80s music).

Zenith2134, I thought that post was pithy rather than hasty. I believe that on this forum once someone reports a post it can on longer be reported by anyone else (though I may have this site confused for ARF no that) so when I promptly reported that post after reading your comment I assumed that you did not report it, and figured I'd inform you how to snipe spammers incase you did not know.

I'm not familiar with the names of most 80's tunes (it was a bit before my time), but do like SOME of the music of that time ( I'm really more of a Big Band/ Swing enthusiast).

Tom C.

Got it. I didn't know how to report posts in fact. I never did in my life! And hopefully never will. So you like Big Band/Swing? Scored a mint copy of Elmer Bernstein's Staccato stereo LP...2nd copy...my grandparents used to listen to this LP all the time when I was growing up...not my thing but it IS good stuff.

Well it is good for the VK community to report spam posts. I try report any spam I see as soon as I see it becaues if someone don't report spam when a bunch of spammers get in (as was just the case) they can mess up the site much more and make it much more of a chore for the moderators to fix.

In short spammers on a forrum are like grafiti "artists"(for lack of a better word) in a neighborhood... the longer one takes to lock them up the more buildings that must be repainted, and as members we should try to act as the neighborhood-watch-group to aid the moderators who play the role of the police here. As members we should all act to keep our community clean, safe and friendly. (climbes down from soapbox)

Never heard of Elmer Bernstein before, but from what a quick net search yielded I now want to search the local thrifts for some of his albums. Thanks for mentioning him I'm always on the look out for discs I don't have and new(to me) artists.

Sorry for going off the threads original topic (I try to avoid that too).

Tom C.

I'm going to start by putting on the test adaptor into the 6BQ5 socket and checking the voltages...I don't think it's a tube-related problem but I will check it just to make sure. The rest of the audio circuit is solid state (IC and transistors). That is the only solid-state part of the set. I may just install a 6AV6 triode as a pre-amplifier and convert the audio input to external only if the IC circuitry is bad as it will always be used with an external audio/video input

Getting back to the original issue at hand, I ran into the same problem with the same chassis. I found a resistor that changed value. It decreased in value. It was the resistor that dropped the B+ supply to the IC and transistor. It ended up destroying the IC. This is probably 25 years ago. The IC was an RCA, so maybe other sets used it as well.

If new ICs can be had I'd put a zenier diode in to prevent any future power supply resistor failure from taking out the IC again.