Philco "Mystery" Remote Radio Control (1939)


Here is Philco's famous Mystery Control, the path breaking wireless remote control introduced in 1939. Prior to that time, several manufacturers offered hard-wired remotes, connected the radio with a long cable, but Philco was the first to make a wireless control.

The Mystery Control was battery powered and completely self-contained. With a large rotary dial and veneered cabinet, it was also a beautiful decorative object. Here are more views of my Mystery Control.


The main purpose of the Mystery Control is to choose stations. I bought this control in Portland, Oregon, and a close look at my dial shows the call signs for Portland stations: KPAM, KPOJ,KGON, KEX, KWJJ, KOIN, KDPQ, and KGW. If you do an Internet search for these call signs, you'll find that some of them are still in use (although not necessarily at their original frequencies).

Moving clockwise around the dial, the last two labels would be SOFT and LOUD (the LOUD label is missing in my control). These were used to turn the radio volume down or up while playing. In addition to choosing stations and changing the volume, the control let you turn the radio off. (It would be impossible to turn the radio on remotely, since without power the radio couldn't receive a signal from the remote control.)

If we remove the back cover and look inside, the top portion of the cabinet contains the dial mechanism and a cable with a plug.


The control's electronics are mounted on the back cover:


The control is a rather simple device, using a battery and one type 30 tube, a large antenna coil, and a few other components. My control even has an original battery, which Philco dubbed the "Mystery Pack."


Of course, this 75-year old battery lost its charge long ago, but it's nice to have one for the sake of completeness. If you wanted to use this control, perhaps you could hollow out this container and conceal new batteries inside.

Mystery Controls were sold with a dozen different Philcos from 1939-1942. As with all handheld remotes, they were often separated from their radios over the decades, so now there are fewer Mystery Controls in existence than radios which could use them. The radios are not very hard to find, but I have never been tempted to buy one, because these sets are large, boring consoles like the model 39-116RX.

Perhaps someday I'll sell this control to someone who could actually use it. Until then, it makes a great display piece!

You can read more about the history and operation of this item at at the Mystery Control page of the Philco Repair Bench website.

Among other things, that website explains how you can straighten a warped dial by clamping it and using heat. The dial is made of Tenite, an early plastic that's notorious for warping. Mine isn't severely warped, but it is bent just enough to rub a little. If I wanted to use the control, I'd remove it and flatten it out.

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