Saturday, February 18, 2023

And Now For Something Completely Different....

 Thought I'd take a break from recounting The Journey, and give a heads up on other projects.

Up first is a 1924 Chelsea Radio set. These were sold under different brand names, and this one is a "Transcontinental Type ZR-4". Almost sounds like a race car from back then, eh? It's from an era 60 years earlier than the FM Stereo gear I've been working on, and a radical departure from all the other radio gear I've worked on.

This was gifted to me by my next door neighbor, who had been trying to get it running for some years. He paid some moron an outrageous amount of money to "repair" it, and another jerk $200 to "refinish" the original wood case.

It's a basic "Three Tube" radio, using Type 01A tubes, a Low-Mu triode, and the most popular radio tube of the 1920's.

The first tube is a regenerative detector, followed by two audio stages. The two black items between the tubes are interstage coupling transformers.

Yep, broken wires in it, after the "repair". Has some bad solder connections, too, but I'll give 'em a pass because they're 100 years old...

The "refinished" cabinet photographs nice, but has 100 years of flaws, dents, and gouges showing. I guess the level of restoration/refinishing wasn't discussed when my neighbor turned this over to the two scoundrels.

Information is a bit sparse about this particular radio, but then I haven't researched into it very deeply. It's a classic circuit from the days when Radio was new, and fairly well documented. I'll also draw my own schematic of it "AS-IS", and replace some of the wiring. The rheostat for adjusting the filament voltage needs to be taken apart, cleaned, and correctly reassembled, as it looks like the previous "repair person" screwed it up. It's also missing a few bits I'll have to fabricate, and I'm not sure if my tube tester can do 4-pin tubes! The Bakelite knobs and front panel need a careful cleaning and relettering, and hopefully they're aren't any dead parts in it that I'll have to chase down. Should be a fun little side project.

And I'm still trying to figure out which is the "clean end" of this thing.

I knew it had taken a hit at some point in it's life, and suspected maybe the chassis was tweaked a bit. I took it apart (again), and started looking at things with a straight edge and a 90* square.

Yep, it was bent.

And not "just a tad tweaked", either.

I'll do an update on this showing how I got it all straight and square again. The front panel now just drops into place, and all the mounting holes line up. No binding any more on the transport mechanism that I can detect.

And still it doesn't work properly.

So I pulled the entire transport out, and will be going through it again, making sure everything is in alignment, and scrupulously clean of any lubricant that could cause slippage. And I finally understand how all the little mechanical bits, linkages, levers, solenoids and idlers work together and interact, causing a couple of light bulbs to illuminate in the old noggin.

I'll get it yet, but yowzur, what a trial........


  1. Love the old radio rig. The technology goes way before my early days of radio interest when vacuum tubes had more than four pins.

    Too bad the tape deck is being ornery. I know you'll keep at it though.

    1. It's definitely a relic of the dim and dusty past. I've never even attempted to use a regenerative set, so it should be interesting.
      As I mentioned before, this is the first "good" tape deck I've ever owned, let alone worked on. NONE of the damage showed in the eBay pix, and all the seller said was it played, and went FF/REW.
      Caveat Emptor!

    2. There's got be like 80 years between the hardware from the first four pictures and the last five. The contrast is stunning.

    3. The ZR-4 was made in the early 1920's, and the CTF-950 was a one-year only model for 1979. so not quite 60 years between manufacture. But your point is well taken, in that the circuit for the radio was designed earlier, and Pioneer continued selling the "big brother" of this deck into the mid 1980's.
      And I still haven't checked to see if my tube tester has a four-pin socket.....

  2. Cassette decks care much more difficult to get just right than almost any other kind of audio tape deck. There is so much crammed into a small space and the tensions and alignment are very critical.

    Some of the early video tape decks were a real pain too, especially some of the professional broadcast gear. Seeing one of the news personnel drop one of the portable video recorders made me want to get their attention with a 2X4.

    1. Yep, 10 pounds crammed into an 8 pound enclosure. I bought all the spring-tension force gauges I'll need for both cassette and reel-to-reel, so I'm good there. To add insult to injury, an "E-Clip" for a 1.5mm (.059") shaft took off for parts unknown last night. Out of all the hardware I've stripped from gear I junked, I never saved any of the e-clips. It's waiting for parts now. I finally understand how the clutches in the reel hubs work during REC/PLAY and FF/REW. They appear to pass all the the tests and checks I've read, so I'm back to the idler tire and its drive mechanism. The e-clip holds the idler tire on the shaft, so I'm hosed until the parts get here.
      I worked on a lot of Sony Digital Beta machines at DirecTV. They were used for on-air programming, and had to be in tip-tip condition. Once a month they'd all get the full Monty per the Sony service manuals. One of our Techs quit, and went to work for a sportscaster. One of his first jobs was to install a high-end, full HD camera, with a $50k lens on it ( ! ) at the Los Angeles Forum so they could broadcast the Lakers in full HD. It was 70~80' in the air up in the ceiling of the Forum, and he dropped it. They took his badge, walked him out the door, and told him to call a cab to get back to his car......

  3. That old radio is a real prize! Good luck with it!

  4. I don't know where my neighbor got it from, but there's a piece of masking tape inside with "The Sutton's First Radio 1920's" written on it. It also has a tag indicating it's licensed under one of Armstrong's patents for "Amateur and Non Commercial Use Only". I'm carefully trying to get the rusted, frozen dial setscrews loose so I can pull them and clean them. They're ancient Bakelite, and require special attention and care in cleaning.


Keep it civil, please....

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