ARMSTRONG, Edwin Howard (Armstrong Edwin Howard)( American electrical engineer.)
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Biography ARMSTRONG, Edwin Howard (Armstrong Edwin Howard)
(1890-1954) Born December 18, 1890 in New York. In 1913 he graduated from Columbia University, majoring in 'Electrical'. He worked there as an assistant at the Department of Electrical Engineering (1913-1914), then moved to a university research laboratory of. Marellusa Hartley and from 1914 to 1935, conducted research and experiments in the field of radio engineering. During the First World War he served in the Army Signal Corps in Paris. In 1934 he became a professor of electrical engineering at Columbia University. In 1912, . trying to understand, . How audion (vacuum tube, . invented in 1906 by De Forest), . Armstrong created the scheme, . they called regenerative (circuit with positive feedback), . through which was 1000-fold amplified high-frequency signals, . In 1913, proposed a scheme for the feedback on the radio, and in 1918 developed the superheterodyne receiver, which has high sensitivity, selectivity and uniform gain across the range of received frequencies. In 1911, Armstrong created sverhregenerativny radio with more amplification, which has found application in mobile radio. In 1925, Armstrong began research aimed at eliminating interference and culminated in the invention of frequency modulation (FM) - a slow change of frequency of electromagnetic waves by a particular law. This method is used for transmission of sound on television and radio broadcasting. In 1939, Armstrong has built on its own means of FM-radio station in Alpine (pc. New Jersey), and in March 1953 announced the establishment of the multiplex method to carry on one FM-channel multiple transmissions. Armstrong died in New York on February 1, 1954.
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