Michele's Mystery Control Demystifier

Welcome to the only page on the web where you can see the Famous Philco Mystery Control in action.

The Mystery Control was the world's first wireless remote control. Introduced by Philco in 1938 for the 1939 model year, it was able to change stations, raise and lower volume, and turn the radio off (but not on) from anywhere in the room up to 25 feet away, all without any wires connecting it to the radio. It was the latest techno-whiz-bang of its day. But it only lasted until 1942. It would be 1956 before anyone would try remote control again (Zenith's famous Space Command).

There's not many of these devices left today but they are truly marvelous little gems of mechanical and electronic ingenuity. Actually seeing one work gives you some appreciation of what folks were able to do over 70 years ago without computers, back in the days before IC's, wi-fi, and Bluetooth.

Here are some short movies that illustrate the Mystery Control in action, controlling a 1939 Philco Model 39-116 console radio. Each movie is an mpeg file less than a minute long. The Mystery Control is operated by turning a dial similar to a rotary telephone dial. It has 10 positions, one for each of eight different stations, one to raise the volume, and one to lower the volume.

Volume is controlled by pressing down on the finger-stop before the dial finishes its return to the home position. This drops a pin down in the way of the wiper arm preventing it from returning all the way and holding the transmitter on as long as you press down. That in turn drives the volume control motor in the desired direction.

In each movie, you first see station 1 being dialed, then stations 5, 7, and 8, as well as the volume being changed. The radio automatically mutes the volume while the station changing is in progress.

Note that clicking the links below just asks your browser to open the file. Your browser must have the appropriate helper app installed to know how to play the mpeg. Microsoft Windows Media Player seems to work well enough. Quicktime is also able to play these. I'm sure there are others too.

Unfortunately, this page is known to NOT work with Internet Explorer. Until I can figure out why, I recommend you use another browser. Sorry about that. I use Firefox.

Watch the Mystery Control transmitter being dialed.

This is what the rotary station switch under the chassis is doing when you spin the dial.

Here's the volume up/down function (dialed with the LOUD and SOFT keys).

See the Mystery Control pulser in action. The last two spins at the end command volume down and volume up, respectively.

Here's what the relays (under the cover in the receiver) do.

This is the ratchet mechanism under the relays in action.

If you're lucky enough to own a Mystery Control and want to get it running, I strongly suggest you check out this page at The Philco Repair Bench. This is the definitive collection of general information, specs, history, schematics, and principles of operation available for the Mystery Control. It is an invaluable reference for the MC owner.

Page last updated on 8/14/09. Visitors since 8/13/09: