[Learadio Model R1 receiver and headphones]

Photograph of a Learadio Model R1 receiver and headphones, circa 1931-1939. The device is on scale to demonstrate its light weight. The caption describes the device's development and specifications.

Typed caption on verso: "C. A Model R-1 battery-operated receiver, which had very good sensitivity. As you can see, it weighs a little less than 16 1/2 lbs, complete with batteries and headphones. It is probably the first time a radio beacon receiver operating directly off dry cells was ever manufactured and sold to private flyers. Covered range of 200-440 KC."