[Learadio remote controller and transmitter remote control]

Photograph of a Learadio remote controller and transmitter remote control, circa 1936. The caption describes the devices' specifications and utility.

Typed caption on verso: "O. (circa 1936) A picture of both the combination remote controller and the transmitter remote control. You will note there were blank spaces on the transmitter selector dial to write in the particular frequencies of the crystals that had been chosen. On the left-hand side of the picture you will see a closeup of the Lear Milemeter, which was like a tuning meter and was the first application of a tuning meter to radio compasses to make sure the compass was properly tuned to the signal. At the same time it would give some indication of how strong the signal was or vice versa, how far you were from the station. There was a switch in the upper lefthand corner for converting from automatic volume control to radio frequency gain control. This was necessary for flying the radio ranges. A switch on the right-hand corner was for receiving either telephone of telegraph signals."