[ccomer1955]

Having just finished working on a 41-280 and a 41-285 back-to-back, and removing an 1940s after market phono jack on the 41-285, I've been staring at the phono jacks on both sets and wondering. They have three needle-small connectors, and are placed in the schematics with the center connector to ground, the left connector to the band switch, and the right connecter to #3 RF broadcast transformer.

If I made one of these IPod adapters ( http://antiqueradio.org/iPodAdaptor.htm ), and fashioned a plug to insert the two leads off an RCA jack/plug, I would need to use the grounded connector for the RCA ground, and use the band switch connector for the signal lead? I would ignore the connector that goes to the RF broadcast transformer?

Would that be correct, or am I off base?

I like the idea of the Radio Shack audio transformers being used to combine the stereo signal into mono, and I really like the idea of using the Philco phono jack instead of making changes to the radio.

So, is this about right, or has anyone done this? I guess IDEALLY, I would need one of the old Philco plugs.

[Raleigh]

Neither of the models you mention had a factory phono input. Based on your description, I think you might be looking at the three-pin external antenna input jack. It doesn't have a number on the schematic, but it is a kind of oval-shaped symbol with three holes directly over the words "84 uuf" for capacitor #9. On the schematic it is wired as you describe.

This connector was for an optional Philco device for owners who wanted to use an external wire antenna instead of the internal loop. It looked like an IF can with a switch on the top and three pins on one side to go into the three-hole socket you mention. Inside was (I think) a coil and a capacitor to match the impedance of either the internal loop or an external wire, depending on which direction the switch was set. I think there must have been screw terminals on the rear side to attach a wire antenna.

Every now and then you see one on eBay for sale with one of the 41-2xx series of radios. There have been a couple of threads in the Phorum with pics of the device, and Ron posted a hand-drawn schematic of the insides.

RCA type connectors were commonly used to connect audio equipment, so they were used for aftermarket phono inputs on radios. The iPod matching device shown on Phil Nelson's page will plug into an RCA jack very similar to those used then. Marcus and Levy have several suggested designs in their book.

Do you know about low-power AM transmitters? Many of us on this Phorum use them to broadcast whatever we want to hear on our radio collections. There are several on the market, usually kits, from $35 or so and up. Most agree that the $100 SSTRAN is about the best, and easy to build. www.sstran.com

I set mine up in the basement with an old stereo amp and tuner, a cd player, and an old laptop. The amplifier's headphone output is plugged into the transmitter. I can listen to just about anything I want that way (and so can my neighbors up to about 1/2 block away!) You could just plug your iPod's headphone jack into the transmitter, and it would sound much the same as if you built the adaptor box and phono input.

Either way you want to go would be a fun project.

[ccomer1955]

Yes. I have one as well, a "Talking House" transmitter. It works very well for me. The project is mainly for the exercise, but also as an add on for one of the radios that I intend to gift to one of my daughters for Christmas. I had assumed it was a phono jack because one of the push button oscillator/pad combinations (the one next to the on/off switch) is marked as "phono."

[Raleigh]

At this time, Philco (and others) made a series of turntables that transmitted over an AM frequency to a radio, so a radio owner wouldn't need to buy a complete phonograph system or modify the radio with a phono input. The phono label on the push-button was to use in case the owner had such a wireless turntable.

If you install a phono input on your radio it wouldn't be factory, but it would certainly be consistent with what many radio owners did in 1941. I'm sure your daughter would enjoy it with her iPod or whatever she has.

Some Philcos had labels in the cabinet that announced that the radio was "TV Ready" or something like that. That was in case the owner had a TV that would broadcast the sound to a nearby radio. I don't think Philco made such a TV in 1941, but I could certainly be wrong about that.

[Edited to add:] My 41-280 has a push-button label that says "Tele-vision" in tiny letters. I left it in place for the novelty. I don't know why the original owner left it there. Maybe he had a TV with wireless sound. I wonder if the phono and television push-button labels were put in at the factory for the owner to change them if the wanted.

[ccomer1955]

By the way, I put the adapter together with the Radio Shack audio transformers and hooked it up to my Crosley 66TC which has a phono connection and a bandswitch setting for it (the setting seems to cut out the RF stage and send the phono signal to the detector). It worked very well, sound levels are perfectly balanced to the volume of the set itself. The whole thing is about the size of a pack of cigarettes. So now all I need is another American Overseas set (because she's not getting mine), and my daughter can have the antique radio IPod dock she wants. ;)

[Raleigh]

Super! You must still have a Radio Shack where you live. All the ones near me have closed.

Did you decide not to modify one of your Philcos for a phono input?

[ccomer1955]

I couldn't bring myself to do it. One of my primary motives for doing this as a hobby was to help preserve the history if I could (that and the idea that it is a bit electronics and a bit furniture finishing).

I kind of pushed my daughter toward the Crosley 66TC because I had already worked on that chassis, and I knew I could put one together for her, AND it had a dedicated phono circuit, AND I happened to already have a spare Crosley 66 chassis laying around. It turned out she liked the looks of the cabinet about as well as anything I had worked on so far which is a small problem because I was counting on being able to source any of the three cabinets for the chassis, and now I have to find one of the wooden ones. Ah well.

I've found a dial cover since this photo was taken.


   

[ccomer1955]

I couldn't bring myself to do it. One of my primary motives for doing this as a hobby was to help preserve the history if I could (that and the idea that it is a bit electronics and a bit furniture finishing).

I kind of pushed my daughter toward the Crosley 66TC because I had already worked on that chassis, and I knew I could put one together for her, AND it had a dedicated phono circuit, AND I happened to already have a spare Crosley 66 chassis laying around. It turned out she liked the looks of the cabinet about as well as anything I had worked on so far which is a small problem because I was counting on being able to source any of the three cabinets for the chassis, and now I have to find one of the wooden ones. Ah well.

I've found a dial cover since this photo was taken.


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