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• Subject > Aids to air navigation (remove)
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• Still Image (41)

• photographic prints (41)
• composite photographs (4)

• Copyright undetermined (41)

• Aids to air navigation (41)
• Radio in aeronautics (34)
• Learadio (27)
• Lear Developments (20)
• Radio--Transmitters and transmission (16)
• Antennas (Electronics) (5)
• Automatic pilot (Airplanes) (5)
• Lear, Inc. (5)
• Radio direction finders (4)
• Airplanes--Cockpits (3)
• Fisher, Herbert O. (3)
• Lear Avia Corporation (3)
• Lear, William P. (William Powell), 1902-1978 (3)
• Canada. Royal Canadian Air Force (1)
• Douglas DC-3 Family (1)
• MacRobertson International Air Race (1934) (1)
• Nichols, Nichols, Reeder Glen, 1904-1975 (1)
• Ontario. Department of Lands and Forests. Forestry Branch (1)
• Pangborn, Clyde Edward, approximately 1893-1958 (1)
• Turner, Roscoe, 1895-1970 (1)
• United States. Army. Signal Corps (1)

41 results

[Learadio combination motor generator and transmitter] (Item)

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] (Item)

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] (Item)

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."

[Learadio aircraft communications system] (Item)

Photograph of a Learadio aircraft communications system, circa 1931-1939. Specific devices pictured include the Model MOPA transmitter (emitator acord unit) and Model R2BB receiver (receptive accord unit).Caption: "Typical aircraft communication system."

[Chassis of Model L Lear-o-Scope] (Item)

Photograph of the chassis of a Model L Lear-o-Scope, circa 1931-1939. The verso inscription, which was written by William P. Lear, describes the development of the device.Inscription on verso: "Here is chassis of Model L Lear-o-Scope. The layout was done by WPL -- Wilbur Webb - now deceased who left me and went to Bendix - and Fred [Coombs?] who could layout and draw up such a unit in a maximum of…

[Model L Lear-o-Scope and loop antenna] (Item)

Photograph of a Model L Lear-o-Scope and loop antenna, circa 1936-1939. The verso inscription, which was written by William P. Lear, describes the device and its development.Inscription on verso: "Note left crank changed bands and moved mash on dial -- Right crank for tuning -- moved freq. dial 200 to 410 KC -- 530 to 1530 KC. Also first time tuning meter used. High Z loop with short tuning coil…

[Learadio Model R-3 aircraft receiver, antenna, and peripheral components] (Item)

Photograph of a Learadio Model R-3 aircraft receiver, shielded loop antenna, and peripheral components, circa 1931-1939. The caption describes the device's development.Typed caption on verso: "P. This loop was metallized in an attempt to shield it, but it was found that the metallizing reduced the 'Q' of the loop so much that it was completely impractical. It was also used in conjunction with an…

[Learadio Model R1 receiver and headphones] (Item)

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…

[Learadio T-30 and R-3 equipment] (Item)

Photograph of a Learadio T-30 R3 radio system and assorted components, circa 1935-1939. The inscription notes that this equipment was developed especially for pilots operating in Alaska.Inscription: "Learadio T-30 R3. Saved many lives and much money for bush pilots in Alaska and northern Canada. Designed in 1935 especially for Alaska flyers. / Trans. 2-freq. -- 3105 6210 and others. Plug-in…

[Assorted Learadio devices] (Item)

Photograph of assorted Learadio devices, circa 1935. Pictured devices include the Model R-3 aircraft receiver, T-30 radio unit, and a shieled loop antenna.Inscription on verso: "Lear equip / circa 1935."