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ionosphere
(Encyclopedia)ionosphere īŏnˈəsfēr [key], series of concentric ionized layers forming part of the upper atmosphere of the earth from around 30 to 50 mi (50 to 80 km) to 250 to 370 mi (400 to 600 km) where it m...microphone
(Encyclopedia)microphone, device for converting sound into electrical energy, used in radio broadcasting, recording, and sound amplifying systems. Its basic component is a diaphragm that responds to the pressure or...Armstrong, Edwin Howard
(Encyclopedia)Armstrong, Edwin Howard, 1890–1954, American engineer and radio inventor, b. New York City, grad. Columbia (E.E. 1913). He was associated in research with Michael I. Pupin at Columbia and became pro...AM, abbreviation for amplitude modulation
(Encyclopedia)AM: see modulation; radio. ...FM, abbreviation for frequency modulation
(Encyclopedia)FM: see modulation; radio. ...modulation, in communications
(Encyclopedia) CE5 Modulation modulation, in communications, process in which some characteristic of a wave (the carrier wave) is made to vary in accordance with an information-bearing signal wave (the modulatin...audio frequency
(Encyclopedia)audio frequency: see sound; radio. ...amplitude modulation
(Encyclopedia)amplitude modulation: see modulation; radio. ...frequency modulation
(Encyclopedia)frequency modulation: see modulation; radio. ...Davis, Elmer
(Encyclopedia)Davis, Elmer, 1890–1958, American newspaperman, radio commentator, and author, b. Aurora, Ind. Davis was a Rhodes scholar (1910–13) at Oxford. For 10 years (1914–24) he was on the staff of the N...Browse by Subject
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