[Lear Developments BC-190-T5 radio transmitter]

Photograph of a Lear Developments BC-190-T5 radio transmitter, circa 1940. The verso inscription notes that this transmitter was developed for the U.S. Army Signal Corps and describes the device's components and specifications.

Inscription on verso: "45 kc to 13 mc 50 watt trans. 4 [illegible] and master osc [oscillator]. Designed about 1940 in Vandalia for first AC operated aircraft of Signal Corps US Army. Note plug in coils for various freq. [frequent] ranges and unit to right is AC power rectifer [rectifier] unit to supply hi voltage DC."