Edwin Howard Armstrong (December 18, 1890 – February 1, 1954) was an American electrical engineer and inventor, who developed FM (frequency modulation) radio and the superheterodyne receiver system.
When the church moved north, the Smiths and Armstrongs followed, and in 1895 the Armstrong family moved from their brownstone row house at 347 West 29th Street to a similar house at 26 West 97th Street in the Upper West Side.
In late 1906, Lee de Forest had invented the three-element (triode) "grid Audion" vacuum-tube.
Much of his early research was conducted in the attic of his parents' house. In 1909, Armstrong enrolled at Columbia University in New York City, where he became a member of the Epsilon Chapter of the Theta Xi engineering fraternity, and studied under Professor Michael Pupin at the Hartley Laboratories, a separate research unit at Columbia.
By 1912, vacuum tube operation was understood, and regenerative circuits using high vacuum tubes were appreciated. While growing up, Armstrong had experimented with the early temperamental, "gassy" Audions.
Although Lee de Forest initially discounted Armstrong's findings, beginning in 1915 de Forest filed a series of competing patent applications that largely copied Armstrong's claims, now stating that he had discovered regeneration first, based on August 6, 1912 notebook entry, while working for the Federal Telegraph company, prior to the January 31, 1913 date recognized for Armstrong.
Further investigation revealed that when the feedback was increased beyond a certain level a vacuum-tube would go into oscillation, thus could also be used as a continuous-wave radio transmitter. Beginning in 1913 Armstrong prepared a series of comprehensive demonstrations and papers that carefully documented his research, and in late 1913 applied for patent protection covering the regenerative circuit.
Although Lee de Forest initially discounted Armstrong's findings, beginning in 1915 de Forest filed a series of competing patent applications that largely copied Armstrong's claims, now stating that he had discovered regeneration first, based on August 6, 1912 notebook entry, while working for the Federal Telegraph company, prior to the January 31, 1913 date recognized for Armstrong.
Kendall of Bell Laboratories. Although most early radio receivers used regeneration Armstrong approached RCA's David Sarnoff, whom he had known since giving a demonstration of his regeneration receiver in 1913, about the corporation offering superheterodynes as a superior offering to the general public.
On October 6, 1914, was issued for his discovery.
Although Lee de Forest initially discounted Armstrong's findings, beginning in 1915 de Forest filed a series of competing patent applications that largely copied Armstrong's claims, now stating that he had discovered regeneration first, based on August 6, 1912 notebook entry, while working for the Federal Telegraph company, prior to the January 31, 1913 date recognized for Armstrong.
Although the legal proceeding twice went before the US Supreme Court, in 1928 and 1934, he was unsuccessful in overturning the decision. In response to the second Supreme Court decision upholding de Forest as the inventor of regeneration, Armstrong attempted to return his 1917 IRE Medal of Honor, which had been awarded "in recognition of his work and publications dealing with the action of the oscillating and non-oscillating audion".
The organization's board refused to allow him, and issued a statement that it "strongly affirms the original award". ===Superheterodyne circuit=== The United States entered into WWI in April 1917.
He had been awarded French patents in 1917 and 1918 that covered some of the same basic ideas used in Armstrong's superheterodyne receiver.
Hammond worked in her uncle's radio laboratory at Columbia University for several years following her graduation from Wellesley College in 1943. ==Honors== In 1917, Armstrong was the first recipient of the IRE's (now IEEE) Medal of Honor. For his wartime work on radio, the French government gave him the Legion of Honor in 1919.
He had been awarded French patents in 1917 and 1918 that covered some of the same basic ideas used in Armstrong's superheterodyne receiver.
Houck, which have been annotated by Mike Katzdorn. Rare Book & Manuscript Library Collections - A collection of images and documents at Columbia University Biography The Broadcast Archive - A brief biography by Donna Halper Ammon, Richard T., "The Rolls Royce Of Reception : Super Heterodynes - 1918 to 1930". IEEE History Center's Edwin H.
An initial court action was triggered in 1919 when Armstrong sued de Forest's company in district court, alleging infringement of patent 1,113,149.
He returned to the US in the autumn of 1919, after being promoted to the rank of Major.
In 1919, Armstrong filed an application for a US patent of the superheterodyne circuit which was issued the next year.
Hammond worked in her uncle's radio laboratory at Columbia University for several years following her graduation from Wellesley College in 1943. ==Honors== In 1917, Armstrong was the first recipient of the IRE's (now IEEE) Medal of Honor. For his wartime work on radio, the French government gave him the Legion of Honor in 1919.
To finance his legal expenses he began issuing non-transferable licenses for use of the regenerative patents to a select group of small radio equipment firms, and by November 1920 17 companies had been licensed.
Although the obvious candidate was the Radio Corporation of America (RCA), on October 5, 1920 the Westinghouse Electric & Manufacturing Company took out an option for $335,000 for the commercial rights for both the regenerative and superheterodyne patents, with an additional $200,000 to be paid if Armstrong prevailed in the regenerative patent dispute.
Westinghouse exercised this option on November 4, 1920. Legal proceedings related to the regeneration patent became separated into two groups of court cases.
(The ongoing patent dispute was not a hindrance, because extensive cross-licensing agreements signed in 1920 and 1921 between RCA, Westinghouse and AT&T meant that Armstrong could freely use the Lévy patent.) Superheterodyne sets were initially thought to be prohibitively complicated and expensive as the initial designs required multiple tuning knobs and used nine vacuum tubes.
This court ruled in Armstrong's favor on May 17, 1921.
(The ongoing patent dispute was not a hindrance, because extensive cross-licensing agreements signed in 1920 and 1921 between RCA, Westinghouse and AT&T meant that Armstrong could freely use the Lévy patent.) Superheterodyne sets were initially thought to be prohibitively complicated and expensive as the initial designs required multiple tuning knobs and used nine vacuum tubes.
A year later, in 1922, Armstrong sold his super-regeneration patent to RCA for $200,000 plus 60,000 shares of corporation stock, which was later increased to 80,000 shares in payment for consulting services.
In 1922 John Renshaw Carson of AT&T, inventor of Single-sideband modulation (SSB), had published a detailed mathematical analysis which showed that FM transmissions did not provide any improvement over AM.
On May 8, 1924, that court ruled that it was de Forest who should be considered regeneration's inventor.
RCA introduced its superheterodyne Radiola sets in the US market in early 1924, and they were an immediate success, dramatically increasing the corporation's profits.
Although the legal proceeding twice went before the US Supreme Court, in 1928 and 1934, he was unsuccessful in overturning the decision. In response to the second Supreme Court decision upholding de Forest as the inventor of regeneration, Armstrong attempted to return his 1917 IRE Medal of Honor, which had been awarded "in recognition of his work and publications dealing with the action of the oscillating and non-oscillating audion".
The subsequent court reviews continued until 1928, when the District of Columbia Court of Appeals disallowed all nine claims of Armstrong's patent, assigning priority for seven of the claims to Lévy, and one each to Ernst Alexanderson of General Electric and Burton W.
Although the Carson bandwidth rule for FM is important today, this review turned out to be incomplete, because it analyzed only what is now known as "narrow-band" FM. In early 1928 Armstrong began researching the capabilities of FM.
These sets were considered so valuable that RCA would not license the superheterodyne to other US companies until 1930. ===Super-regeneration circuit=== The regeneration legal battle had one serendipitous outcome for Armstrong.
Houck, which have been annotated by Mike Katzdorn. Rare Book & Manuscript Library Collections - A collection of images and documents at Columbia University Biography The Broadcast Archive - A brief biography by Donna Halper Ammon, Richard T., "The Rolls Royce Of Reception : Super Heterodynes - 1918 to 1930". IEEE History Center's Edwin H.
In 1931 the RCA engineers constructed a successful FM shortwave link transmitting the Schmeling–Stribling fight broadcast from California to Hawaii, and noted at the time that the signals seemed to be less affected by static.
He was granted five US patents covering the basic features of new system on December 26, 1933.
He set up a self-financed independent research and development laboratory at Columbia, and owned his patents outright. In 1934, he filled the vacancy left by John H.
Although the legal proceeding twice went before the US Supreme Court, in 1928 and 1934, he was unsuccessful in overturning the decision. In response to the second Supreme Court decision upholding de Forest as the inventor of regeneration, Armstrong attempted to return his 1917 IRE Medal of Honor, which had been awarded "in recognition of his work and publications dealing with the action of the oscillating and non-oscillating audion".
In 1934 he presented his new system to RCA president Sarnoff.
From May 1934 until October 1935 Armstrong conducted field tests of his FM technology from an RCA laboratory located on the 85th floor of the Empire State Building in New York City.
From May 1934 until October 1935 Armstrong conducted field tests of his FM technology from an RCA laboratory located on the 85th floor of the Empire State Building in New York City.
In 1936 he published a landmark paper in the Proceedings of the IRE that documented the superior capabilities of using wide-band FM.
Crosby (inventor of Crosby system for FM Stereo) in the same journal provided further analysis of the wide-band FM characteristics, and introduced the concept of "threshold", demonstrating that there is a superior signal-to-noise ratio when the signal is stronger than a certain level. In June 1936, Armstrong gave a formal presentation of his new system at the US Federal Communications Commission (FCC) headquarters.
In 1937 it introduced what became known as the Apex band, consisting of 75 broadcasting frequencies from 41.02 to 43.98 MHz.
In early 1940, the FCC held hearings on whether to establish a commercial FM service.
Article placements promoting both Armstrong personally and FM were made with general circulation publications including The Nation, Fortune, The New York Times, Atlantic Monthly, and The Saturday Evening Post. In 1940, RCA offered Armstrong $1,000,000 for a non-exclusive, royalty-free license to use his FM patents.
A publicity photograph was made of him presenting Marion with the world's first portable superheterodyne radio as a wedding gift. He was an avid tennis player until an injury in 1940, and drank an Old Fashioned with dinner.
He held 42 patents and received numerous awards, including the first Medal of Honor awarded by the Institute of Radio Engineers (now IEEE), the French Legion of Honor, the 1941 Franklin Medal and the 1942 Edison Medal.
Following this review, the FCC announced the establishment of an FM band effective January 1, 1941, consisting of forty 200 kHz-wide channels on a band from 42–50 MHz, with the first five channels reserved for educational stations.
Existing Apex stations were notified that they would not be allowed to operate after January 1, 1941 unless they converted to FM. Although there was interest in the new FM band by station owners, construction restrictions that went into place during WWII limited the growth of the new service.
He held 42 patents and received numerous awards, including the first Medal of Honor awarded by the Institute of Radio Engineers (now IEEE), the French Legion of Honor, the 1941 Franklin Medal and the 1942 Edison Medal.
Hammond worked in her uncle's radio laboratory at Columbia University for several years following her graduation from Wellesley College in 1943. ==Honors== In 1917, Armstrong was the first recipient of the IRE's (now IEEE) Medal of Honor. For his wartime work on radio, the French government gave him the Legion of Honor in 1919.
The FCC made its decision final on June 27, 1945.
In late 1945, Armstrong contracted with John Orr Young, founding member of the public relations firm Young & Rubicam, to conduct a national campaign promoting FM broadcasting, especially by educational institutions.
A book published in 1946 by Charles A.
They achieved success on 10 January 1946. ==Death== Bitter and overtaxed by years of litigation and mounting financial problems, Armstrong lashed out at his wife one day with a fireplace poker, striking her on the arm.
Outraged by this, in 1948 Armstrong filed suit against RCA and the National Broadcasting Company, accusing them of patent infringement and that they had "deliberately set out to oppose and impair the value" of his invention, for which he requested treble damages.
A period of allowing existing FM stations to broadcast on both low and high bands ended at midnight on January 8, 1949, at which time any low band transmitters were shut down, making obsolete 395,000 receivers that had already been purchased by the public for the original band.
Although he was confident that this suit would be successful and result in a major monetary award, the protracted legal maneuvering that followed eventually began to impair his finances, especially after his primary patents expired in late 1950. ==FM radar== During World War II, Armstrong turned his attention to investigations of continuous-wave FM radar funded by government contracts.
Edwin Howard Armstrong (December 18, 1890 – February 1, 1954) was an American electrical engineer and inventor, who developed FM (frequency modulation) radio and the superheterodyne receiver system.
She left their apartment to stay with her sister, Marjorie Tuttle, in Granby, Connecticut. Sometime during the night of January 31–February 1, 1954, with his wife in Connecticut and three servants having left for the day, Armstrong removed the air conditioner from a window in his 12-room apartment on the 13th floor of River House in Manhattan, New York City, and jumped to his death.
In late December 1954, it was announced that through arbitration a settlement of "approximately $1,000,000" had been made with RCA.
Politically, he was described by one of his associates as "a revolutionist only in technology – in politics he was one of the most conservative of men." In 1955, Marion Armstrong founded the Armstrong Memorial Research Foundation, and participated in its work until her death in 1979 at the age of 81.
Politically, he was described by one of his associates as "a revolutionist only in technology – in politics he was one of the most conservative of men." In 1955, Marion Armstrong founded the Armstrong Memorial Research Foundation, and participated in its work until her death in 1979 at the age of 81.
postage stamp in 1983.
(This paper would be reprinted in the August 1984 issue of Proceedings of the IEEE.) A year later, a paper by Murray G.
2, February 1991 Hong, Sungook, "A History of the Regeneration Circuit: From Invention to Patent Litigation" University, Seoul, Korea (PDF) Who Invented the Superhetrodyne? The history of the invention of the superhetrodyne receiver and related patent disputes Yannis Tsividis, "Edwin Armstrong: Pioneer of the Airwaves", 2002.
Documentary that first aired on PBS in 1992. ==External links== Armstrong Memorial Research Foundation - The Armstrong Foundation disseminates knowledge of Armstrong's research and achievements Houck Collection - A collection of images and documents that belonged to Armstrong's assistant, Harry W.
The Consumer Electronics Hall of Fame inducted him in 2000, "in recognition of his contributions and pioneering spirit that have laid the foundation for consumer electronics." Columbia University established the Edwin Howard Armstrong Professorship in the School of Engineering and Applied Science in his memory. Philosophy Hall, the Columbia building where Armstrong developed FM, was declared a National Historic Landmark.
2, February 1991 Hong, Sungook, "A History of the Regeneration Circuit: From Invention to Patent Litigation" University, Seoul, Korea (PDF) Who Invented the Superhetrodyne? The history of the invention of the superhetrodyne receiver and related patent disputes Yannis Tsividis, "Edwin Armstrong: Pioneer of the Airwaves", 2002.
Louis: Telescope Books, 2008. Ken Burns.
Baltimore: Johns Hopkins University Press, 2010.
Edwin Howard Armstrong's niece, Jeanne Hammond, who represented the family in the Ken Burns documentary "Empire of the Air", died on May 1, 2019 in Scarborough, Maine.
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