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[TWA Douglas DC-1 aircraft at airfield]
Photograph of a TWA Douglas DC-1 aircraft (tail and wing number NR223Y) at an airfield, circa 1935-1938. A man in a TWA jumpsuit stands near the aircraft. The caption notes that this aircraft was outfitted with a Model L Learscope during its record-setting coast-to-coast flight on April 30, 1935.Typed caption on verso: "A. This was an experimental installation of a Model L Learscope on a TWA…
[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…
[Lear Developments Type T-120 transmitter]
Photograph of a Lear Developments Type T-120 transmitter, circa 1936-1939. The caption on verso notes that transmitter was developed for the Royal Canadian Air Force and describes the device's components and specifications. Caption on verso: "J. This transmitter/receiver combination was designed for the Canadian RAF and called the Type T-120, built around 1936-37 and was essentially an R3 receiver…
[Lear radio compass]
Photograph of a Lear radio compass, circa 1931-1939.
[Lear device] (Item)
[Lear device]
Photograph of a Lear device, circa 1931-1939.
[Lear Developments telephone transmitter]
Composite photograph of a Lear Developments telephone transmitter, showing views of the internal components and the external case, circa 1931-1939. The verso inscription, which was written by William P. Lear, states that this was the first 3105-3120 kc 35-watt telephone transmitter made for private pilots.Inscription on verso: "The first 3105-3120 KC 35 watt telephone transmitter ever made for…
[Lear Developments special aircraft receiver and remote control unit]
Photograph of a Lear Developments special aircraft receiver and remote control unit (radio transmitter Type L-35S-1), circa 1931-1939. The verso caption notes that the receiver was developed for the Ontario Forestry Branch and describes the device's components and specifications. Typed caption on verso: "V. The control head for the Ontario Forestry Branch of the Dept. of Lands and Forests of…
[Learadio combination motor generator and transmitter]
Composite photograph of a Learadio combination motor generator and transmitter, showing views of the internal components and the external case, circa 1935-1937. The verso caption states that this was one of the first transmitting devices for private pilots. Typed caption on verso: "E. This is a combined motor generator and transmitter to operate on 3015 and 3120 KC. It was produced in quantities…
[Various components for Learadio T30R3 installation]
Photograph of various components for a Learadio T30R3 installation, circa 1931-1939. The verso caption describes the problems and capabilities of the trailing antenna.Typed caption on verso: "G. Shows a complete set of equipment for a T30R3 installation. You will note that the antenna consisting of a trailing rope that was always hanging out of the airplane without a weight on it, and the big…
[Learadio Type TR-50 transmitter]
Photograph of a Learadio Type TR-50 transmitter, showing views of the internal components and the external case, circa 1931-1939.Typed caption on verso: "T. Shows the original effort to make a more powerful transmitter by using tubed in parallel. This was a two-frequency transmitter and operated on 3105 and 3120 KCs."