Ewdn Armstrong
Developed and advanced the utility of FM technology.
Born	December 18, 1890(1890-12-18) New York, NY
Died	January 31, 1954 (aged 63) New York, NY
Occupation	electrical engineer and inventor
Known for	inventor of FM radio

Edwin Howard Armstrong (December 18, 1890 – January 31, 1954) was an American electrical engineer and inventor. Armstrong was the inventor of frequency modulation (FM) radio. Download high resolution version (700x1015, 339 KB)Edwin Armstron, FM radio inventor This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... is the 352nd day of the year (353rd in leap years) in the Gregorian calendar. ... Year 1890 (MDCCCXC) was a common year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Monday of the Julian calendar). ... New York, New York and NYC redirect here. ... This article is about the state. ... is the 31st day of the year in the Gregorian calendar. ... Year 1954 (MCMLIV) was a common year starting on Friday (link will display full calendar) of the Gregorian calendar. ... New York, New York and NYC redirect here. ... This article is about the state. ... An engineers degree is an academic degree which is intermediate in rank between a masters degree and a doctorate; it is occasionally to be encountered in the United States in technical fields. ... For other uses, see Inventor (disambiguation). ... FM radio is a broadcast technology invented by Edwin Howard Armstrong that uses frequency modulation to provide high-fidelity sound over broadcast radio. ... is the 352nd day of the year (353rd in leap years) in the Gregorian calendar. ... Year 1890 (MDCCCXC) was a common year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Monday of the Julian calendar). ... is the 31st day of the year in the Gregorian calendar. ... Year 1954 (MCMLIV) was a common year starting on Friday (link will display full calendar) of the Gregorian calendar. ... An engineers degree is an academic degree which is intermediate in rank between a masters degree and a doctorate; it is occasionally to be encountered in the United States in technical fields. ... For other uses, see Inventor (disambiguation). ... In telecommunications, frequency modulation (FM) conveys information over a carrier wave by varying its frequency. ...

Birth and education

Edwin Howard Armstrong was born in New York City, New York, in 1890. He studied at Columbia University and later became a professor there. He invented the regenerative circuit while he was an undergraduate and patented it in 1914, the super-regenerative circuit (patented 1922), and the superheterodyne receiver (patented 1918).^[1] New York, New York redirects here. ... Alma Mater Columbia University is a private university in the United States and a member of the Ivy League. ... The regenerative circuit (or self-regenerative circuit) allows a signal to be amplified many times by the same vacuum tube or other active component such as a field effect transistor. ... For other uses, see Patent (disambiguation). ... In electronics, the superheterodyne receiver (also known by its full name, the supersonic heterodyne receiver, or by the abbreviated form superhet) is a technique for selectively recovering the information from radio waves of a particular frequency. ...

Work and patent disputes

Many of Armstrong's inventions were ultimately claimed by others in patent lawsuits. In particular, the regenerative circuit, which Armstrong patented in 1914 as a "wireless receiving system," was subsequently patented by Lee De Forest in 1916; De Forest then sold the rights to his patent to AT&T. Between 1922 and 1934, Armstrong found himself embroiled in a patent war, between himself, RCA, and Westinghouse on one side, and De Forest and AT&T on the other. At the time, this action was the longest patent lawsuit ever litigated, at 12 years. Armstrong won the first round of the lawsuit, lost the second, and stalemated in a third. Before the Supreme Court of the United States, De Forest was granted the regeneration patent in what is today widely believed to be a misunderstanding of the technical facts by the Supreme Court.^[2] Lee De Forest, (August 26, 1873 – June 30, 1961) was an American inventor with over 300 patents to his credit. ... This article is about the current AT&T. For the 1885-2005 company, see American Telephone & Telegraph. ... RCA, formerly an acronym for the Radio Corporation of America, is now a trademark owned by Thomson SA through RCA Trademark Management S.A., a company owned by Thomson. ... Westinghouse logo (designed by Paul Rand) The Westinghouse Electric Company, headquartered in Monroeville, Pennsylvania, is an organization founded by George Westinghouse in 1886. ... The Supreme Court of the United States (sometimes colloquially referred to by the acronym SCOTUS[1]) is the highest judicial body in the United States and leads the federal judiciary. ...

Columbia's Philosophy Hall. Armstrong developed FM radio in its basement lab.

FM radio

Even as the regenerative-circuit lawsuit continued, Armstrong was working on another momentous invention. While working in the basement lab of Columbia's Philosophy Hall, he created wide-band frequency modulation radio (FM, patented in 1933 as US patent 1941066 with the title of "Radio signalling system"). Rather than varying the amplitude of a radio wave to create sound, Armstrong's method varied the frequency of the wave instead. FM radio broadcasts delivered a much clearer sound, free of static, than the AM radio dominant at the time. In 1922, John Renshaw Carson of AT&T, inventor of Single-sideband modulation (SSB modulation), had published a paper in the Proceedings of the Institute of Radio Engineers (IRE) arguing that FM did not appear to offer any particular advantage ^[3]. Rodins The Thinker with Philosophy Hall in the background Philosophy Hall is the home of the English, Philosophy, and several language departments at Columbia University in New York City. ... In telecommunications, frequency modulation (FM) conveys information over a carrier wave by varying its frequency. ... The abbreviations FM, Fm, and fm may refer to: Electrical engineering Frequency modulation (FM) and its most common applications: FM broadcasting, used primarily to broadcast music and speech at VHF frequencies FM synthesis, a sound-generation technique popularized by early digital synthesizers Science Femtometre (fm), an SI measure of length... For other uses, see Patent (disambiguation). ... Mediumwave radio transmissions (sometimes called Medium frequency or MF) are those between the frequencies of 300 kHz and 3000 kHz. ... Single-sideband modulation (SSB) is a refinement of the technique of amplitude modulation designed to be more efficient in its use of electrical power and bandwidth. ... Following several attempts to form a technical organization of wireless practitioners in 1908-1912, the Institute of Radio Engineers (IRE) was finally established in 1912 in New York. ...

Armstrong managed to demonstrate the advantages of FM radio despite Carson's skepticism in a now-famous paper on FM in the Proceedings of the IRE in 1936 ^[4], which was re-printed in the August 1984 issue of Proceedings of the IEEE ^[5]. The Institute of Electrical and Electronics Engineers or IEEE (pronounced as eye-triple-ee) is an international non-profit, professional organization incorporated in the State of New York, United States. ...

Today the consensus regarding FM is that narrow band FM is not so advantageous in terms of noise reduction, but wide band FM can bring great improvement in signal to noise ratio if the signal is stronger than a certain threshold. Hence Carson was not entirely wrong, and the Carson bandwidth rule for FM is still important today. Thus, both Carson and Armstrong ultimately contributed significantly to the science and technology of radio. The threshold concept was discussed by Murray G. Crosby (inventor of Crosby system for FM Stereo) who pointed out that for wide band FM to provide better signal to noise ratio, the signal should be above a certain threshold, according to his paper published in Proceedings of the IRE in 1937 ^[6]. Thus Crosby's work supplemented Armstrong's paper in 1936. The phrase signal-to-noise ratio, often abbreviated SNR or S/N, is an engineering term for the ratio between the magnitude of a signal (meaningful information) and the magnitude of background noise. ... In telecommunication, Carsons bandwidth rule defines the approximate bandwidth requirements of communications system components for a carrier signal that is frequency modulated by a continuous or broad spectrum of frequencies rather than a single frequency. ... The Crosby system was an FM stereophonic broadcasting standard, developed by Murray G. Crosby, that used an FM subcarrier for higher fidelity. ...

However, FM radio proved to be too revolutionary for RCA (Radio Corporation of America), Armstrong's then-employer. He was asked to remove his transmitting equipment from RCA's Empire State Building offices after his 1935 demonstrations of the technology, in order to make way for television equipment. A June 17, 1936, presentation at the Federal Communications Commission (FCC) headquarters made headlines nationwide. He played a jazz record over conventional AM radio, then switched to an FM broadcast. "[I]f the audience of 50 engineers had shut their eyes they would have believed the jazz band was in the same room. There were no extraneous sounds," noted one reporter. He added that several engineers described the invention "as one of the most important radio developments since the first earphone crystal sets were introduced." ^[7] RCA, formerly an acronym for the Radio Corporation of America, is now a trademark owned by Thomson SA through RCA Trademark Management S.A., a company owned by Thomson. ... The Empire State Building is a 102-story Art Deco skyscraper in New York City, New York at the intersection of Fifth Avenue and West 34th Street. ... FCC redirects here. ...

In 1937, Armstrong financed construction of the first FM radio station, W2XMN, a 40 kilowatt broadcaster in Alpine, New Jersey. The signal (at 42.8 MHz) could be heard clearly 100 miles (160 km) away, despite the use of less power than an AM radio station. ^[8] Alpine is a borough in Bergen County, New Jersey, United States. ...

RCA began to lobby for a change in the law or FCC regulations that would prevent FM radios from becoming dominant. By June of 1945, the RCA had pushed the FCC hard on the allocation of electromagnetic frequencies for the fledgling television industry. Although they denied wrongdoing, David Sarnoff and RCA managed to get the FCC to move the FM radio spectrum from (42-50 MHz), to (88-108 MHz), while getting new television channels allocated in the 40-MHz range. This article is about the political effort. ... The abbreviation FCC can refer to: Face-centered cubic (usually fcc), a crystallographic structure Federal Communications Commission, a US government organization Farm Credit Corporation/Farm Credit Canada, a Canadian government organization Families with Children from China, an adoption support organization Florida Christian College, a college in central Florida Fresno City... Sarnoff redirects here. ...

This single FCC action rendered all Armstrong-era FM sets useless overnight, and protected RCA's AM-radio stronghold. Armstrong's radio network did not survive the frequency shift up into the high frequencies; most experts believe that FM technology was set back decades by the FCC decision. This change was strongly supported by AT&T, because loss of FM relaying stations forced radio stations to buy wired links from AT&T. This article is about the current AT&T. For the 1885-2005 company, see American Telephone & Telegraph. ...

Furthermore, RCA also claimed invention of FM radio and won its own patent on the technology. A patent fight between RCA and Armstrong ensued. RCA's momentous victory in the courts left Armstrong unable to claim royalties on any FM radios sold in the United States. The undermining of Yankee Network and Patent Court battle brought ruin to Armstrong, by then almost penniless and emotionally distraught. The Yankee Network was an American radio network. ...

Alone and driven to despair over the FM debacle, Armstrong, dressed in full coat and hat, jumped to his death from the thirteenth floor window of his New York City flat on January 31, 1954.^[9] His widow Marion, who had been Sarnoff's secretary before marrying Armstrong, renewed the patent fight against RCA and finally prevailed in 1967.^[10] It took decades following Armstrong's death for FM broadcasting to meet and surpass the saturation of the AM band, and longer still for FM radio to become profitable for broadcasters. is the 31st day of the year in the Gregorian calendar. ... Year 1954 (MCMLIV) was a common year starting on Friday (link will display full calendar) of the Gregorian calendar. ... FM broadcasting is a broadcast technology invented by Edwin Howard Armstrong that uses frequency modulation (FM) to provide high-fidelity sound over broadcast radio. ...

Armstrong was of the opinion that anyone who had actual contact with the development of radio understood that the radio art was the product of experiment and work based on physical reasoning, rather than on the mathematicians' calculations and formulae (known today as part of "mathematical physics"). For the controversy about who invented radio, see Invention of radio. ... In the scientific method, an experiment (Latin: ex- periri, of (or from) trying) is a set of observations performed in the context of solving a particular problem or question, to retain or falsify a hypothesis or research concerning phenomena. ... Leonhard Euler, considered one of the greatest mathematicians of all time A mathematician is a person whose primary area of study and research is the field of mathematics. ... A calculation is a deliberate process for transforming one or more inputs into one or more results. ... A formula is a concise way of expressing information symbolically (as in a mathematical or chemical formula) or a general relationship between quantities. ... Mathematical physics is the scientific discipline concerned with the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories. ...

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 received in 1942 the AIEEs Edison Medal "For distinguished contributions to the art of electric communication, notably the regenerative circuit, the superheterodyne, and frequency modulation". The ITU added him to its roster of great inventors of electricity in 1955. In 1980 he was inducted into the National Inventors Hall of Fame, and was on a U.S. postage stamp in 1983. 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." ire has several uses: as a morpheme, the suffix -ire, as in fire, sire, wire, retire, entire; Ire, a mountain in France as an acronym, Investigative Reporters and Editors, Institute of Radio Engineers, Iron Realms Entertainment, or Innovating regions in Europe ire is another name for anger or wrath. ... The IEEE Medal of Honor is the highest recognition of the IEEE, and has been awarded once each year since 1917, when its first recipient was Major Edwin H. Armstrong. ... Medal for the officer class, decorated with a rosette Napoleon wearing the Grand Cross The President of France is the Grand Master of the Legion. ... Year 1919 (MCMXIX) was a common year starting on Wednesday (link will display the full calendar). ... Year 1942 (MCMXLII) was a common year starting on Thursday (the link will display the full 1942 calendar) of the Gregorian calendar. ... The American Institute of Electrical Engineers was a United States based organization of electrical engineers that existed between 1884 and 1963 (when it merged with the Institute of Radio Engineers (IRE)). The 1884 founders of the American Institute of Electrical Engineers (AIEE) included some of the most prominent inventors and... The IEEE Edison Medal is presented by the IEEE for a career of meritorious achievement in electrical science, electrical engineering or the electrical arts. ... This article is about the location. ... Year 1955 (MCMLV) was a common year starting on Saturday (link displays the 1955 Gregorian calendar). ... Year 1980 (MCMLXXX) was a leap year starting on Tuesday (link displays the 1980 Gregorian calendar). ... Exterior of the National Inventors Hall of Fame museum, 2005 The National Inventors Hall of Fame is an organization that honors important inventors from the whole world. ... A selection of Hong Kong postage stamps A postage stamp is evidence of pre-paying a fee for postal services. ... Year 1983 (MCMLXXXIII) was a common year starting on Saturday (link displays the 1983 Gregorian calendar). ... The Consumer Electronics Hall of Fame, founded by the Consumer Electronics Association, CEA, honors the leaders whose creativity, persistence, determination and sheer personal charisma helped to shape an industry and made the consumer electronics marketplace what it is today. ... Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ...

Philosophy Hall, the Columbia building where Armstrong developed FM, was declared a National Historic Landmark in 2003 in recognition of that fact. Armstrong's home in Yonkers also received a similar designation, but it was withdrawn when the house was later demolished. This article or section needs additional references or sources to improve its verifiability. ... This article does not cite any references or sources. ... For other uses, see Demolition (disambiguation). ...

See also

• Armstrong Tower : tall lattice tower built and used by Edwin Armstrong in 1938.

Armstrong Tower is a 129. ...

Patents

Armstrong received 42 patents in total; a selection are listed below:

• U.S. Patent 1,009,951  : "Electric Dynamo and Motor"
• U.S. Patent 1,113,149  : "Wireless receiving system"
• U.S. Patent 1,334,165  : "Electric Wave Transmission" (Note: Co-patentee with M. I. Pupin)
• U.S. Patent 1,336,378  : "Antenna with distributed positive resistance"
• U.S. Patent 1,342,885  : "Method of receiving high frequency oscillation"
• U.S. Patent 1,415,845  : "Selctively opposing impedance to received electrical oscillations" (Note: Co-patentee with M. I. Pupin)
• U.S. Patent 1,424,065  : "Signaling system"
• U.S. Patent 1,611,848  : "Wireless receiving system for continuous wave"
• U.S. Patent 1,941,066  : "Radio signaling system" (Note: This is the patent for FM.)

References and notes

Walter H. Schottky (July 23, 1886, Zürich, Switzerland - March 4, 1976, Pretzfeld, West Germany) was a German physicist who invented the screen-grid vacuum tube in 1915 and the tetrode in 1919 while working at Siemens. ... Find A Grave is an online database of seventeen million cemeteries and burial records. ... The New York Times is an internationally known daily newspaper published in New York City and distributed in the United States and many other nations worldwide. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 202nd day of the year (203rd in leap years) in the Gregorian calendar. ...

Further reading

• Lawrence Lessing, Man of High fidelity: Edwin Howard Armstrong, Philadelphia, J.B. Lippincott Company, 1956
• Lewis, Tom. Empire of the air: the men who made radio. New York : E. Burlingame Books, 1991.

• Empire of the Air was also the title of a related Ken Burns documentary which aired on PBS in 1992. [1]

• Süsskind, Charles (1970). "Armstrong, Edwin Howard". Dictionary of Scientific Biography 1. New York: Charles Scribner's Sons. 287-288. ISBN 0684101149. 

Lawrence Lessing is associate editor of Fortune Magazine and winner of the 1965 AAAS-Westinghouse Science Journalism Award for his article in Fortune on the causes of earthquakes. ... Kenneth Lauren Burns (born July 29, 1953) is an American director and producer of documentary films known for his style of making use of original prints and photographs. ... Not to be confused with Public Broadcasting Services in Malta. ... The Dictionary of Scientific Biography is a reference work consisting of extensive biographies of scientists from antiquity to modern times, excluding scientists who were alive when the Dictionary was first put out. ...

External links

Wikiquote has a collection of quotations related to:

Edwin Howard Armstrong

• a Biography of Armstrong
• Photos and records relating to Edwin H. Armstrong, from the Houck Collection
• Katzdorn, Mike, "Edwin H. Armstrong"
• Halper, Donna, "Major Edwin Howard Armstrong" (Barry Mishkind website)
• Ammon, Richard T., "The Rolls Royce Of Reception : Super Heterodynes - 1918 to 1930".
• IEEE History Center's Edwin H. Armstrong : Excerpt from "The Legacy of Edwin Howard Armstrong," by J. E. Brittain Proceedings of the IEEE, vol. 79, no. 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. A profile on the web site of Columbia University, Armstong's alma mater