ARMSTRONG, EDWIN HOWARD 189O-1954

Inventor of fm radio

Last Great Inventor

Edwin Howard Armstrong ranks with Alexander Graham Bell and Thomas Edison as one of the greatest of American inventors. Like them, he was a gifted and original thinker, as responsible for modern radio as Edison was for the electric light or Bell for the telephone. Like them, Armstrong worked obsessively and held himself to high moral standards, Unlike them, Armstrong was born in a century when science was rapidly moving from the inventor's shed to the corporate laboratory. In a sense Armstrong was the last of the great nineteenth-century inventors, an individualistic genius who fit poorly into the modern technocracy. While Bell and Edison reaped the rewards of their skills in wealth and prestige and built modern corporations on their inventions, Armstrong spent his life defending his inventions from corporations and had his wealth and prestige stripped from him. By 1954, despondent, bankrupt, his life and marriage shattered by four decades of lawsuits, he killed himself. It was a tragic end for one of the most gifted engineers of the twentieth century.

Background

Edwin Howard Armstrong was born in 1890 to a prosperous New York family. His mother was a teacher, and his father was an executive for Oxford University Press. Armstrong grew up immersed in middle-class Presbyterian values, eagerly absorbing tales of thrift, persistence, and honesty associated with successful inventors such as Edison and Guglielmo Marconi. By high school he was consumed with the new "wireless" (radio) craze, building his own receivers and antennas and communicating in Morse code with stations as far away as Key West, He attended the School of Mines, Engineering and Chemistry at Columbia University, where he learned about the latest innovations in electricity and physics. By the time he was graduated in June 1913 he had earned distinction as a highly unorthodox, inquisitive, and original student. He had already built two inventions that would transform radio technology: a feedback circuit that increased the receptive power of radio receivers, and a feedback circuit that transmitted continuous radio waves. These two inventions made modern radio possible. He followed them with the superheterodyne, a device capable of tuning in and deciphering radio signals transmitted at a very high frequency. Built while Armstrong served in the U.S. Army Signal Corps during World War I, the superheterodyne remains the tuning mechanism used in radio and television today. By the early 1920s the patent rights for the superheterodyne and a superregeneration circuit had made Armstrong wealthy, and he was among the most acclaimed inventors in the United States. By the 1930s his title to his inventions had been stripped from him.

Patents

Armstrong filed for a patent on his feedback receiver on 19 October 1913; on 18 December of that year he filed for a patent on the circuit capable of generating continuous radio waves. But he was too late. His circuit worked in a device invented by Lee De Forest, the audion. De Forest filed his own patent for a similar amplification circuit in 1915. Although De Forest did not file for his patent until after Armstrong had filed for his, on the face of it De Forest had a strong claim to have built the refinement to his own invention, which he claimed to have done in 1912. For the next nineteen years Armstrong and De Forest filed infringement suit after infringement suit against one another. The suits demonstrated the strength of Armstrong's claim, and he won several judgments against De Forest. But the regeneration circuit became essential in commercial radio, and large corporations, such as Radio Corporation of America (RCA) and American Telephone and Telegraph (AT&T), had vested interests in the outcome of the case, royalties to be gained by their ownership of De Forest's patent. Despite the previous rulings against De Forest, RCA and AT&T appealed the case to the U.S. Supreme Court, and AT&T hired a former associate justice of the Supreme Court, Charles Evans Hughes, to argue for de Forest. Armstrong lost the case and his legal right to royalties from his invention. Similarly, AT&T used a dispute with a former associate of Armstrong's, Lucian Levy, to file a case against Armstrong's patent rights to the superheterodyne. In 1928 the courts awarded the patent to AT&T. Armstrong, however, was undeterred. In 1933 he filed a case on somewhat different grounds to regain his patent to the regeneration circuit and once again won decisions against De Forest in the lower courts. In the Supreme Court, however, Armstrong was again defeated in a decision whose embrace of flawed science was condemned by many engineers and scientists. In 1934 the professional body of the Institute of Radio Engineers affirmed that, whatever the judgment of the Supreme Court, Armstrong was the inventor of the regeneration circuit.

FM

Chastened by his experience in the courts, Armstrong returned to his laboratory for his next technological breakthrough, FM (frequency modulation) radio. FM radio solved one of the most vexing problems in early radio, the presence of static in the transmission. Caused by electrical interference, thunderstorms, car engines, and sunspots, static frequently interrupted radio broadcasts. Armstrong solved the problem by inventing a technology that most engineers and scientists considered impossible in theory and unworkable in practice. Rather than modulating the amplitude (height) of the carrier wave, Armstrong varied the frequency (length) of the carrier wave. FM required that Armstrong construct a completely new technology of broadcasting, and it worked. FM transmissions were free of static and, moreover, carried a wider range of sound, giving birth to the first high-fidelity transmissions. Once again, Armstrong had revolutionized radio.

Stalled

Armstrong's revolutionary technology, however, was too radical for the times. Despite conclusive tests demonstrating the efficacy of FM, skeptics denied what their own ears heard. Mathematical models had indicated that FM could not work, and therefore they remained convinced that it did not work. Commercial radio, moreover, was becoming slightly less lucrative. The Depression cut into advertising revenues, and technological improvements in AM transmission drove down the profitability of radio receivers. FM technology would entail huge startup costs and compete with existing AM systems, further eroding profits. Large corporations such as RCA were banking on a new broadcast technology, television, and were scarcely interested in FM, which they considered merely a refinement in AM broadcasting. Armstrong, unfortunately, was contractually bound to offer the new technology to RCA. RCA did not want the new system, but they did not want their competitors to get it either, and they did everything they could to prevent the introduction of FM. Because RCA would not allow him to use their transmitters, Armstrong applied for an experimental broadcast license to begin FM transmissions. Then RCA imposed on friends at the Federal Communications Commission (FCC) to deny Armstrong a license. With virtually no merit, RCA contested Armstrong's FM patents with the U.S. Patent Office and then imitated his circuits in slightly modified form, arguing that their technology was original and unique. Simultaneously, RCA engineers testified in FCC hearings and in the newspapers that FM technology was unworkable.

World War II

World War II disproved the claims of FM detractors. The new technology proved vital to battlefront communications, becoming standard issue in walkie-talkies, tanks, and jeeps. Armstrong himself modified the technology for use in radar, creating early-warning radar and other applications that remain classified in the 1990s. In 1946 he successfully bounced an FM-modified radar signal off the moon, inaugurating modern earth-to-space communications. As a patriotic gesture, Armstrong waived all rights to patent royalties on his products for the duration of the war, an act that cost him millions. RCA was not nearly so generous, receiving cost-plus contracts for goods based on Armstrong's inventions and an annual royalty of $4 million.

Last Battle

The efficacy of FM during the war moved RCA to redouble its efforts to squelch it after the war. In 1945, with prodding from RCA, the FCC moved FM transmissions from the very high frequency bandwidths of the electromagnetic spectrum to the untested ultra high frequency range. The decision immediately made fifty FM broadcasting stations and a half million FM radios obsolete. When the FCC followed this decision with one reducing the wattage of FM transmitters, FM seemed nearly dead. But Armstrong fought on. He modified FM technology for the new transmission bands and continued to challenge RCA in court. Ultimately, in the 1970s, Armstrong's efforts resulted in FM becoming the dominant radio medium around the world. In the 1950s, however, Armstrong was racing against time and money. RCA's efforts to marginalize FM effectively limited Armstrong's royalties and income; patents on some of his technologies were due to expire in 1950, after which his abilities to pay court costs would be further compromised. RCA stalled, tying Armstrong up in court, bleeding his financial resources. Still Armstrong was able to produce technical innovations. In 1953 he and his associate John Bose developed FM multiplexing, the sending of different signals on a single carrier wave, which made stereo broadcasting possible. It was his last invention. By 1954 Armstrong was bankrupt, and his thirty-year marriage had collapsed. On Sunday, 31 January 1954, Armstrong jumped from a thirteenth-floor apartment in New York City. Less than a month later, David Sarnoff, chairman of RCA, announced to stockholders that RCA's profits had reached an all-time high of $850 million.

Source:

Tom Lewis, Empire of the Air: The Men Who Made Radio (New York: HarperCollins, 1991).

Armstrong, Edwin Howard

(b. New York, N. Y., 18 December 1890; d. New York, 1 February 1954)

radio engineering.

Armstrong’s father, John Armstrong, was a publisher who became vice-president in charge of the American branch of Oxford University Press; his mother, Emily Smith, graduated from Hunter College and taught for ten years in New York public schools before her marriage in 1888. When Armstrong was twelve, the family moved to Yonkers, New York, where he attended high school and became interested in radiotelegraphy. He entered Columbia University at nineteen and studied electrical engineering under Michael Idvorsky Pupin, the inventor of the Pupin loading coil used in long-distance telegraphy and telephony, graduating in 1913.

While still an undergraduate, Armstrong made the first of his many inventions, one of four that proved to be particularly significant; the triode feedback (regenerative) circuit. That invention, and the negative-bias grid circuit invented by Frederick Löwenstein, ultimately led to wide to wide utlization of the as yet little-exploited triode (invented in 1906 by Lee De Forest), but Armstrong became embroiled in patent litigation and received only modest royalties.

In 1917, after serving as an assistant at Columbia for some years, Armstrong became a U.S. Army Signal Corps officer when the United States entered World War I. He was sent to France and while there developed his second important invention, the super-heterodyne circuit, and improvement on the heterodyne circuit that was invented in 1905 by Reginald Aubrey Fessenden. In the heterodyne circuit, the received signal is mixed with a locally generated signal to produce an audible “beat” note at a frequency equal to the difference between those of the two signals; Armstrong’s method which greatly improved the sensitivity and stability of radio recivers extented the technique to much higher frequencies and shifted the beat note above the audible range.

Upon returning to America, Armstrong was once again beset by patent interference proceedings, although his personal fortunes took a turn for the better he sold his feedback and superheterodyne patents to Westinghouse Electric & Manufacturing Company(retaining royalty-earning licensing rights for the use of amateurs); he resumed his position at Columbia University; and he married Marion Maclnnis, secretary to David sarnoff, then general manager of the Radio Corporation of America.

In 1921 Armstrong made his third important discovery, superregeneration—a method of overcoming the regenerative receiver’s principal limitation, the tendency to burst into oscillations just as the point of maximum amplification was reached. RCA purchased the patent but it did not yield the company much in royalties, since it was unsuited for broadcast receivers; it did not come into its own until special applications were developed many years later. However, RCA profited greatly from the “superhet,” to which it had acquired the rights through a cross license with Westinghouse. Armstrong found himself a millionaire.

The next decade of his life was marred by the long battle with De Forest over the feedback patents. The case was taken to the U.S. Supreme Court but Armstrong lost on a legal technicality. Before that decision had been handed down, however, Armstrong had completed and patented his greatest invention, frequency modulation (FM). Once again he was beset by difficulties : the U.S. radio industry resisted the introduction of FM broadcasting, FM production was interrupted when the United States entered World War II, and the Federal Communications Commission dealt FM a stunning blow in 1945 when it relegated it to a new frequency band and put restrictions on transmitter power, thus making over fifty existing transmitters and half a million receivers obsolete. At the same time, FM came to be widely used in military and other mobile communications, radar, telemetering, and the audio portion of television; but widespread adoption of FM broadcasting came only after Armstrong’s death. Exhausted by a five—year suit for patent infringement against RCA and almost destitute as his FM patents began to expire, Armstrong committed suicide in 1954.

He had received many honors, including the highest awards of the two U.S. electrical engineering societies, the American Institute of Electrical Engineers (Edison Medal, 1942) and the Institute of Radio Engineers (Medal of Honor, 1918, reaffirmed in 1934 when he tried to return it after losing the legal fight against De Forest); the Franklin Medal (1941); and, for his war work, the U.S. Medal for Merit (1945). No inventor contributed more profoundly to the art of electronic communication. Armstrong is one of the two dozen honored in the Pantheon of the International Telecommunications Union in Geneva.

BIBLIOGRAPHY

Armstrong received forty-two patents and wrote twentysix papers; the papers are listed in his biography by Lawrence Lessing, Man of High Fidelity (Philadelphia, 1956). See also obituaries in New York Times (2 Feb. 1954), p. 27; and in Proceedings of the Institute of Radio Engineers, 42 (1954), 635.

Charles SÜsskind

Edwin Howard Armstrong

The American electrical engineer and radio inventor Edwin Howard Armstrong (1890-1954) was one of a small group who made fundamental contributions to the development of radio.

Edwin Armstrong was born in New York City, where his father was the American representative of the Oxford University Press. Armstrong rode his motorcycle to classes at Columbia University, and he took a degree in electrical engineering in 1913. He remained at Columbia for the rest of his life, serving as research assistant to Michael Pupin and, on the latter's death in 1934, as professor of electrical engineering.

Armstrong had one of those turbulent careers typical of so many inventors, especially those working in new and rapidly developing industries. Driven by a thirst for historical vindication and a love of legal combat, perhaps more than by the desire for money, inventors have plagued each other's lives to a remarkable degree. Armstrong took out his first patent before he finished college in 1913, and patents and disputes over them always seem to have occupied an inordinate amount of his time and effort.

His early and long association with Prof. Pupin gave Armstrong direct access to one of the best and most fertile minds in the electrical field. Armstrong's academic base also kept him free of connection with any of the many companies then vying for dominance in the radio field; he was one of the few men to successfully maintain such independence.

The radio was not one invention but a combination of inventions, many of them of disputed origin. Armstrong's first important contribution was his realization of the value of Lee De Forest's audion vacuum tube as a means of amplifying current. To Armstrong this realization appeared to rank alongside the invention of the audion itself. Armstrong's second contribution was the feedback circuit, another means of amplifying current, which he (and others independently) worked out in 1912. The following year he discovered that the audion could be used to generate high-frequency oscillations; again, there were several contemporary claims to this discovery.

While serving as a signal officer in World War I, Armstrong developed in 1918 the superheterodyne circuit, in which incoming high-frequency signals were beaten against low-frequency signals from a local oscillator so that they could be detected. After the war he sold his feedback and superheterodyne patents to the Westinghouse Company for $350,000 and received even more from the Radio Corporation of America (RCA) for a superregenerative invention. His last great contribution was frequency modulation (FM), a method of overcoming static in broadcasting, on which he worked from 1924 to 1933 in the face of indifference and even hostility from large manufacturers and broadcasters.

During his last years perhaps 90 percent of Armstrong's time was taken up by court battles with the National Broadcasting Company, and others; this poisoned his life. He died, an apparent suicide, in 1954.

Further Reading

There is no biography of Armstrong. A brief discussion of his work is in John Jewkes, David Sawers, and Richard Stillerman, The Sources of Invention (1958). The standard history of the radio is William R. Maclaurin, Invention and Innovation in the Radio Industry (1949). Two other useful books are Donald M. McNicol, Radio's Conquest of Space (1946), and Carl F.J. Overhage, ed., The Age of Electronics (1962).

Additional Sources

Lewis, Thomas S. W., The Legacies of Edwin Howard Armstrong: the regenerative circuit, the superheterodyne circuit, the superregenerative circuit, frequency modulatio, Radio Club of America, 1990. □

Edwin Howard Armstrong 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 professor there in 1934. Armstrong received numerous awards for his contributions to the development of radio, which include the invention of the regenerative circuit (1912); the superheterodyne circuit (1918), the basic circuit of nearly all modern radio receivers; the superregenerative circuit (1920); and wideband frequency modulation (FM) system (1925–33). In 1947 he received the Medal of Merit for his contributions to military communications during World War II.