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  #1  
Old 09-04-2011, 05:44 PM
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Chad Hauris Chad Hauris is offline
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1971 Curtis Mathes tube type color set

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.
Attached Images
File Type: jpg cm_front_small.jpg (81.3 KB, 141 views)
File Type: jpg cm_control_small.jpg (73.7 KB, 97 views)
File Type: jpg cm_chassis_test.jpg (87.5 KB, 108 views)
File Type: jpg cm_fly_small.jpg (57.2 KB, 98 views)
File Type: jpg cm_crt_small.jpg (55.0 KB, 80 views)
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  #2  
Old 09-04-2011, 05:55 PM
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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?
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  #3  
Old 09-04-2011, 06:27 PM
DaveWM DaveWM is offline
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wow that cabinet is hideous, but at least the chassis is well made, Nice fly.
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  #4  
Old 09-04-2011, 07:32 PM
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Quote:
Originally Posted by DaveWM View Post
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,
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Old 09-04-2011, 09:50 PM
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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.
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  #6  
Old 09-05-2011, 06:29 AM
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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.
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Old 09-05-2011, 11:31 AM
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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 09-05-2011, 12:05 PM
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Last edited by andy; 12-05-2021 at 08:20 PM.
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  #9  
Old 09-05-2011, 12:25 PM
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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
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  #10  
Old 09-05-2011, 01:03 PM
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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!
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Old 09-05-2011, 01:11 PM
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Quote:
Originally Posted by andy View Post
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.
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Old 09-05-2011, 10:24 PM
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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.
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Old 09-06-2011, 09:01 AM
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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!
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  #14  
Old 09-06-2011, 06:10 PM
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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.
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Old 09-07-2011, 10:18 AM
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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!
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