Cool 1950's 'Atomic Age' Tabletop Radio

[Mars_Amp_Repair]

Hey folks,
Just got one of these in to repair. Just needs filters. GE model 861. Gotta love the matching red line cord!
Note the Death cap for the line input jack. I'm old enough to remember when these were new and when a consumer might actually use their tabletop radio to plug a turntable in
Glen

GE_861.jpg

GE_861-Tube-Chart.jpg

GE_861-PCB.jpg

[sluckey]

That would make a good companion for my GE toaster oven.

[stephen_w_keller]

Attached are the schematic and parts list for the GE Model 861 table top radio.

It looks like you could convert this into a little practice amp:

• add an isolation transformer

• add a three-wire cord, making sure to ground the chassis

• yank the interstage transformers, tuning cap and antenna

• wire up the pentodes as audio gain stages

• add a tone control of some sort

• add an input jack

• probably a few other bits that won't manifest until one is halfway through the effort...

Et viola! it's a guitar amp is born. Of course the antique radio collectors would cringe at this.

Four gain stages would be pretty hard to tame as well. I think it's an interesting thought exercise to see what one can do with these old table top sets. Doing the work, however, is difficult; the things are usually rat's nests inside and hard to work on.

Stph

[stephen_w_keller]

The fact that the circuit is on a PCB will complicate things.

[R.G.]

Be careful. This is the classic five-tube "widowmaker" power setup.

Even if you add a three wire cord and safety ground the chassis, you're still vulnerable to an incorrectly wired AC socket, high impedance ground, a few other things. If you're intending to put an audio input on it, it would be much safer to find a small ac mains isolation transformer that you could tuck into the chassis somewhere. Electrocution is so forever.

[martin manning]

It already has a Phono input, but I don’t know how one would have used that since most phonographs already had built in audio amps. In any case, leaving it as it is makes a lot more sense.

[stephen_w_keller]

It already has a Phono input, but I don’t know how one would have used that since most phonographs already had built in audio amps. In any case, leaving it as it is makes a lot more sense.

Agreed. I've converted a few radios to amps over the years. It's always more complex than building something from scratch. It's fun to think about how to do, but it is almost never practical. Leaving it as a beautiful example of mid-50's americana is the most sensible thing.

Stph

[didit]

It already has a Phono input, but I don’t know how one would have used that since most phonographs already had built in audio amps. In any case, leaving it as it is makes a lot more sense.

Pure speculative waving -- however, there were companies building small table radios that would have matched tiny mono 45 players with ceramic or crystal cartridges. No idea if GE was one of them.

..

[martin manning]

These seem to be somewhat desirable. From one listing:

"The "Leave It To Beaver" Radio...These GE Atomic Age tube radios. Models 861 (red) and 862 (blue) shown here. There is a third model 860 in brown. These mid-centuries were produced in the mid 1950s, the dawn of the Space Age. This GE radio was seen in the kitchen of the Cleaver family on the TV show, "Leave It To Beaver"----an added incentive for collectors."

[Mars_Amp_Repair]

Hey guys,
I found an episode that shows the Atomic Radio in Wally & The Beaver's bedroom. It started out there & then was apparently moved to the kitchen, where a kitchen tabletop radio should be anyway!
Enjoy, Glen

Atomic_Radio_On Leave it to Beaver.jpg

[Mars_Amp_Repair]

Also,
If you look closely at the volume control on the schematic which has a tap, you'll find the input jack there. The one I have for repair behaves this way: With volume control fully almost fully CCW, it cuts out the radio & engages the input jack. On the front panel there is an indication that about 1/8th turn from fully CCW, the phono input is engaged. Pretty cleaver. I'll bet that Volume/on-off pot is absolutely made of unobtainium!
BTW, it is a push-pull power switch on the vol pot.
Glen

[stephen_w_keller]

Also,
If you look closely at the volume control on the schematic which has a tap, you'll find the input jack there. The one I have for repair behaves this way: With volume control fully almost fully CCW, it cuts out the radio & engages the input jack. On the front panel there is an indication that about 1/8th turn from fully CCW, the phono input is engaged. Pretty cleaver. I'll bet that Volume/on-off pot is absolutely made of unobtainium!
BTW, it is a push-pull power switch on the vol pot.
Glen

Unobtanium, indeed. I ran across a bunch of Clarostat pots with various odd-ball taps a couple of decades ago at a surplus shop. They were too expensive to justify back then, so I passed. I didn't have any application for them and didn't know where they were used. I wished I'd picked them up. Should-a, would-a, could-a. I reckon they are even more scarce now. Oh well.

Stph

[solderhead]

Is that one of the "All American Five" radios that come with a hot chassis that's only insulated by the plastic case?

Be careful.

[stephen_w_keller]

Is that one of the "All American Five" radios that come with a hot chassis that's only insulated by the plastic case?

Be careful.

Yep. That's why an isolation transformer and proper grounding would be requirements to make something like this work as a guitar amp. You don't want to convert one of these without a thorough understanding of the circuit. These are fun to think about converting, but that doesn't make it safe. Frankly, keeping an "Atomic Age" radio intact and functional for its original purpose is the wise choice.