Browse Items (60 total)

Photograph of a Learadio airport telephone transmitter, circa 1931-1939. Inscription: "This 15-watt power transmitter was habitually able to work aircraft 250 miles away. Freq. 278 kc."

Photograph of a Lear Developments aircraft transmitter, circa 1931-1939. The verso caption notes that this transmitter was developed for the Flight International Corporation and describes the device's components and specifications.Typed caption on…

Photograph of a Lear device, circa 1931-1939.

Photograph of a Lear radio compass, circa 1931-1939.

Photograph of a Lear device, circa 1931-1939.

Photograph of the internal components of a Lear device, circa 1931-1939.

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…

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…

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.…

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…