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The definitive site on Edwin Armstrong is by Mike Katzdorn. I reccomend it as your primary source. I would suggest you only come back to this page AFTER visiting Mike's site. And trust me - you probably won't need to !

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Edwin Howard Armstrong, b. New York City, Dec. 18, 1890, d. Feb. 1, 1954, was an American inventor and electrical engineer who made fundamental contributions to radio. His invention of the regenerative (feedback) circuit in 1912, while he was still in college, was challenged by Lee De Forest in a series of lengthy patent suits.

Although Armstrong lost the case, the scientific community continued to support his claims. In 1918 he invented the superheterodyne circuit, which uses the heterodyne principle. His invention (1925-33) of the system of (FM) frequency modulation eliminated radio static.

This invention, however, was also challenged in a patent suit. In poor health, with most of his money gone, he committed suicide. Armstrong has posthumously received increasing recognition for his many important inventions.

Source: The New Grolier Multimedia Encyclopedia

Edwin Armstrong was from a genteel, devoutly Presbyterian family of Manhattan. His father was a publisher andhis mother a former schoolteacher. Armstrong was a shy boy interested from childhood in engines, railwaytrains, and all mechanical contraptions.

At age 14, fired by reading of the exploits of Guglielmo Marconi in sending the first wireless message acrossthe Atlantic Ocean, Armstrong decided to become an inventor. He built a maze of wireless apparatus in hisfamily's attic and began the solitary, secretive work that absorbed his life.

Except for a passion for tennis and,later, for fast motor cars, he developed no other significant interests. Wireless was then in the stage of crudespark-gap transmitters and iron-filing receivers, producing faint Morse-code signals, barely audible throughtight earphones. Armstrong joined in the hunt for improved instruments. On graduating from high school,he commuted to Columbia University's School of Engineering.

In his junior year at Columbia, Armstrong made his first, most seminal invention. Among the devicesinvestigated for better wireless reception was the then little understood, largely unused Audion, orthree-element vacuum tube, invented in 1906 by Lee De Forest, a pioneer in the development of wirelesstelegraphy and television.

Armstrong made exhaustive measurements to find out how the tube worked anddevised a circuit, called the regenerative, or feedback, circuit, that suddenly, in the autumn of 1912, broughtin signals with a thousandfold amplification, loud enough to be heard across a room. At its highest amplification, he also discovered, the tube's circuit shifted from being a receiver to being an oscillator, orprimary generator, of wireless waves. As a radiowave generator, this circuit is still at the heart of all radio-television broadcasting.

Armstrong's priority was later challenged by De Forest in a monumental series of corporate patent suits, extending more than 14 years, argued twice before the U.S. Supreme Court, and finally ending--in ajudicial misunderstanding of the nature of the invention--in favour of De Forest. But the scientific communitynever accepted this verdict.

The Institute of Radio Engineers refused to revoke an earlier gold-medal award to Armstrong for the discovery of the feedback circuit. Later he received the Franklin Medal, highest of theUnited States' scientific honours, reaffirming his invention of the regenerative circuit.

This youthful invention that opened the age of electronics had profound effects on Armstrong's life. It led him, after a stint as an instructor at Columbia University, into the U.S. Army Signal Corps laboratories in World War I in Paris, where he invented the superheterodyne circuit, a highly selective means ofreceiving, converting, and greatly amplifying very weak, high-frequency electromagnetic waves, which today underlies 98 percent of all radio, radar, and television reception over the airways.

It brought him into early association with the man destined to lead the postwar Radio Corporation of America (RCA), David Sarnoff, whose young secretary Armstrong later married.

Armstrong himself returned after the war to Columbia University to become assistant to Michael Pupin, the notable physicist and inventor and his revered teacher.In this period he sold patent rights on his circuits to the major corporations, including RCA, for large sums incash and stock. Suddenly, in the radio boom of the 1920s, he found himself a millionaire. But he continued to teach at Columbia, financing his own research, working along with Pupin, whose professorship heinherited, on the long-unsolved problem of eliminating static from radio.

Source: Bellingham Radio Museum

Edwin Howard Armstrong was the father of FM radio and the grandfather of radar and a great grandfather of space communication, but he never reaped the full reward of his genius.

Young Howard Armstrong had been so full of life. In his teens, he was charged with energy, and totally wrapped up in radio. He liked girls, but he was too busy to date. He studied his head off at Columbia University. He drove a red motorcycle. He liked to climb towers and hang from his heels when he got to the top. And he was always ready to question the untested (and frequently wrong) theories of some of his professors.

Armstrong didn't invent radio. Alexander Popov and Guglielmo Marconi and Lee de Forest get the credit for that. But, in 1912, at the age of 22, Armstrong found out for himself how Lee de Forest's radio tube really worked -- and redesigned it by taking the electromagnetic waves (or electrons) that came from a radio transmission and feeding the signal back through the tube again and again, each time increasing its power as much as 20,000 times a second.

He called the phenomenon "regeneration." It was the most important advance in the young history of radio, because, when the feedback was increased beyond a critical level, the tube gave forth an oscillation that created its own radio waves. Armstrong made the de Forest tube into a transmitter as well as a receiver. It not only amplified radio signals. It generated them as well. And this advance made all the difference. Now radio engineers no longer needed 20-ton generators to get their stations on the air.

Armstrong patented his discovery in 1913, and licensed it to the Marconi company in 1914. And then he was off to France to fight in World War I. On the battlefields of western Europe, Captain Armstrong discovered that the American Expeditionary Force had little or no radio. Almost single handedly, he remedied that situation, on the ground, and in the air.

He personally designed and outfitted the fledging Allied air force with radios, often going up and testing them himself. Then, while still stationed in Paris, he invented something then called the superheterodyne receiver, a complex bit of electronic sorcery that is still basic to the tuner found in almost every radio and television and radar.

In 1920, Westinghouse bought Armstrong's patent for the superheterodyne receiver, and started up the nation's first radio station, KDKA in Pittsburgh. It signalized its accomplishment by broadcasting the election returns that brought Warren G. Harding to the White House. All of a sudden, radio was the craze of the post- war period. Kids in America started making their own crystal sets.

Other manufacturers started making their own brand of "radiola." Other stations came on the air. Though all this, Marconi's company, the Radio Corporation of America, had been sitting on the sidelines, content to concentrate on its international telegraph business. But not for long. RCA soon bought up all of Westinghouse's radio patents, and those of AT &T and any others who had them, including Armstrong's patents for regeneration.

Another radio pioneer, Lee deForest, objected. He said regeneration was his idea, and started legal procedures with the U.S. Patent Office. He lost his case, but then went on to pursue appeals against Armstrong in the federal courts for almost two decades. He lost his case at every step of the way, and then, in a legal fluke, won his final appeal before the U.S. Supreme Court. Much to the outrage of scientists and engineers from coast to coast, a Supreme Court judge misunderstood the case, and ended up siding with de Forest.

So did RCA. If de Forest won his suit against Armstrong, RCA would retain control of its patent for an extra ten years. So RCA gave no help to Armstrong, even though the company lawyers knew what the truth was. The truth was that Armstrong had helped create an industry which, in 1934, a depression year, was worth almost $2 billion. Everybody -- RCA, Zenith, Philco, Magnavox, Motorola and Crosley -- they were all turning fantastic profits, using Armstrong's inventions.

And Armstrong went on inventing. He started working on radio's static problem, experimenting with what would later become known as frequency modulation, something that other scientists had already decided wouldn't work. One of the experts, John Renshaw Carson, a researcher at Bell Laboratories, said,

"I have proved, mathematically, that this type of modulation inherently distorts without any compensating advantages whatsoever. Static, like the poor, will always be with us."

"I could never accept findings based almost exclusively on mathematics. It ain't ignorance that causes all the trouble in this world. It's the things people know that ain't so."

Armstrong completed his first field test on June 9, 1934, sending an organ recital, via both AM and FM, from an RCA tower on top of the Empire State Building to the home of a trusted old friend on Long Island. The FM organ came through loud and clear. The AM version had "hundreds of thousands times more static." He did other tests, at longer distances, during the "summer static" season. Not only did those experiments work. Armstrong proved that the signal did not fade at the perimeter as AMs did.

FM not only eliminated static. It also produced a better sound, three times better than AM. Listeners could distinguish the on-air differences between the whine of a rip saw and the huff of a cross cut. Furthermore, FM delivered sounds that spanned the full range of the human ear, from the deep rumble of a kettle drum to the delicate keening of a flute, spanning a range between 50 cycles and 15,000 cycles.

At best, AM delivered 5,000 cycles. Armstrong had discovered hi-fi. Armstrong also found that a single FM carrier wave could transmit two radio programs at once, a telegraph message and a facsimile of the front page of The New York Times. He'd discovered multiplexing.

During World War II, Armstrong did important research on long range radar for the War Department and gave his FM patents to the military for no fee, an important gift, once the U.S. commanders realized that the German army traveled on AM, which they could easily jam. FM was unjammable.

By the end of the war, Armstrong had developed his continuous wave FM radar to the point where he was able to bounce a radio signal 238,000 miles -- to the moon and back again. He had proven that FM waves, unlike AM waves, could penetrate the ionosphere. That paved the way for radio communication in space, and it gave astronomers a new tool to measure distances from the earth to the ends of the universe.

By the end of World War II, FM had been proven. Much to the disgust of RCA's David Sarnoff.

"I thought Armstrong would invent some kind of a filter to remove static from our AM radio. I didn't think he'd start a revolution, start up a whole damn new industry to compete with RCA."

"A new kind of radio," said Sarnoff, "is like a new kind of mouse trap. The world doesn't need another mousetrap."

And he got General Electric to start working with him. GE made a discovery of its own. FM signals did not interfere with one another. An FM radio simply picked up the stronger signal. This meant that a number of low-power stations could operate in close proximity, and that more stations could use a small part of the electromagnetic spectrum.

And so, FM stations started to proliferate. There were already 40 of them in 1939. In May 1940, the FCC allotted the 42-50 megacycle band to FM radio; in two months, it received more than 500 FM applications, and still others continued to pour in. The National Television Standards Committee decided that FM should be the standard for the audio portion of the TV broadcast signal. Armstrong was sanguine. He predicted, "In three or four years, there will be more FM listeners than there are now for AM.

He was right. But Armstrong would see no personal rewards for all his work and all his genius. Now he found that RCA and all of America's big communication giants were teaming up to stifle FM, and take away all the rewards Armstrong had been waiting for. He'd expected royalties on the manufacture of FM receivers. He expected to negotiate contracts with FM broadcasters. He also expected royalties on every TV set sold, in the U.S. and, eventually, abroad, for TV's sound system was his, FM.

But that wasn't going to happen. RCA tried to circumvent Armstrong's patents, and began producing televisions with his sound system, but paying him nothing, and then, finally, offering him $1 million for a non-exclusionary license. It was something like a scene from the Old West, the rich rancher going to his upstart competitor next door and saying, "I'm going to give you $1 million for your spread. Do you want me to pay you, or do want me to pay your widow?"

Congress moved to an inquiry, with Sen Charles W. Tobey of New Hampshire taking the lead on Armstrong's side. Sen. Tobey said,

"RCA has been doing everything it can to keep Armstrong down. They did their damnedest to ruin FM. At the same time, they were supplying free TV sets to commissioners of the FCC."

For Armstrong, time was running out. RCA could afford the legal fees. Armstrong had to sell many of his assets, including his stock in Zenith and RCA and Standard Oil, for $200,000. With all of his other expenses, including the expense of running his research facility at Columbia University, Armstrong could afford to pay only $22,000 to his lawyers.

By 1954, he was ready to settle. He asked RCA for $2.4 million. RCA countered with $200,000, less than the outstanding bill for his legal fees. Armstrong appealed to his wife, Marion. Would she advance him some of the money he had given her years ago? She objected. That was the money for their retirement.

Exhausted and out of hope, frustrated by all the litigation, Armstrong exploded in a great rage. He swung a poker at Marion. The blow landed on her arm. She fled to her sister in Connecticut. Armstrong had shattered his happy marriage of nearly 30 years. He spent Christmas and New Year's alone in his New York apartment. Then, on January 31, 1954, he wrote a final letter to Marion.

I am heartbroken because I cannot see you once again.

I deeply regret what has happened between us. I cannot

understand how I could hurt the dearest thing in the whole

world to me. I would give my life to turn back to the time

when we were so happy and free. God keep you and may

the Lord have mercy on my soul.

David Sarnoff told the press, "I did not kill Armstrong."

A month later, Sarnoff announced at RCA's annual meeting that the company had reached an all-time high earnings of more than $850 million. At the end of that meeting, one man stood before his fellow stockholders and told them to "have faith and confidence in Uncle Sam of the United States of America and in Daddy David of RCA."

Armstrong's lawyers stuck with Armstrong's widow, working on contingency until they finaly squeezed a settlement out of RCA: Marion would get a little more than a million dollars, the same amount that Sarnoff had offered Armstrong in 1940. In effect, Sarnoff had finally gotten an answer to the question: "Do you want me to pay you, or your widow?"

Source: http://www.wsone.com/fecha/armstrong.htm

Edwin Howard Armstrong (b. Dec. 18, 1890, New York, N.Y., U.S.--d. Jan. 31/Feb. 1, 1954, New York City), American inventor who laid the foundation for much of modern radio and electronic circuitry, including the regenerative and superheterodyne circuits and the frequency modulation (FM) system.

Early life.

Armstrong was from a genteel, devoutly Presbyterian family of Manhattan. His father was a publisher and his mother a former schoolteacher. Armstrong was a shy boy interested from childhood in engines, railway trains, and all mechanical contraptions.

At age 14, fired by reading of the exploits of Guglielmo Marconi in sending the first wireless message across the Atlantic Ocean, Armstrong decided to become an inventor. He built a maze of wireless apparatus in his family's attic and began the solitary, secretive work that absorbed his life. Except for a passion for tennis and, later, for fast motor cars, he developed no other significant interests.

Wireless was then in the stage of crude spark-gap transmitters and iron-filing receivers, producing faint Morse-code signals, barely audible through tight earphones. Armstrong joined in the hunt for improved instruments. On graduating from high school, he commuted to Columbia University's School of Engineering.

In his junior year at Columbia, Armstrong made his first, most seminal invention. Among the devices investigated for better wireless reception was the then little understood, largely unused Audion, or three-element vacuum tube, invented in 1906 by Lee De Forest, a pioneer in the development of wireless telegraphy and television.

Armstrong made exhaustive measurements to find out how the tube worked and devised a circuit, called the regenerative, or feedback, circuit, that suddenly, in the autumn of 1912, brought in signals with a thousandfold amplification, loud enough to be heard across a room.

At its highest amplification, he also discovered, the tube's circuit shifted from being a receiver to being an oscillator, or primary generator, of wireless waves. As a radiowave generator, this circuit is still at the heart of all radio-television broadcasting.

Armstrong's priority was later challenged by De Forest in a monumental series of corporate patent suits, extending more than 14 years, argued twice before the U.S. Supreme Court, and finally ending, in a judicial misunderstanding of the nature of the invention, in favour of De Forest.

But the scientific community never accepted this verdict. The Institute of Radio Engineers refused to revoke an earlier gold-medal award to Armstrong for the discovery of the feedback circuit. Later he received the Franklin Medal, highest of the United States' scientific honours, reaffirming his invention of the regenerative circuit.

This youthful invention that opened the age of electronics had profound effects on Armstrong's life. It led him, after a stint as an instructor at Columbia University, into the U.S. Army Signal Corps laboratories in World War I in Paris, where he invented the superheterodyne circuit, a highly selective means of receiving, converting, and greatly amplifying very weak, high-frequency electromagnetic waves, which today underlies 98 percent of all radio, radar, and television reception over the airways.

It brought him into early association with the man destined to lead the postwar Radio Corporation of America (RCA), David Sarnoff, whose young secretary Armstrong later married. Armstrong himself returned after the war to Columbia University to become assistant to Michael Pupin, the notable physicist and inventor and his revered teacher.

In this period he sold patent rights on his circuits to the major corporations, including RCA, for large sums in cash and stock. Suddenly, in the radio boom of the 1920s, he found himself a millionaire. But he continued to teach at Columbia, financing his own research, working along with Pupin, whose professorship he inherited, on the long-unsolved problem of eliminating static from radio.

Invention of FM broadcasting.

In 1933 Armstrong secured four patents on advanced circuits that were to solve this last basic problem. They revealed an entirely new radio system, from transmitter to receiver. Instead of varying the amplitude, or power, of radio waves to carry voice or music, as in all radio before then, the new system varied, or modulated, the waves' frequency (number of waves per second) over a wide band of frequencies.

This created a carrier wave that natural static, an amplitude phenomenon created by electrical storms, could not break into. As a result, FM's wide frequency range made possible the first clear, practical method of high-fidelity broadcasting.

Because the new system required a basic change in transmitters and receivers, it was not embraced with any alacrity by the established radio industry. Armstrong had to build the first full-scale FM station himself in 1939 at a cost of more than $300,000 to prove its worth. He then had to develop and promote the system, sustain it through World War II (while he again turned to military research), and fight off postwar regulatory attempts to hobble FM's growth.

When FM slowly established itself, Armstrong again found himself entrapped in another interminable patent suit to retain his invention. Ill and aging in 1954, with most of his wealth gone in the battle for FM, he took his own life.

The years have brought increasing recognition of Armstrong's place in science and invention. FM is now the preferred system in radio, the required sound channel in all television, and the dominant medium in mobile radio, microwave relay, and space-satellite communications.

Posthumously, Armstrong was elected to the pantheon of electrical greats by the International Telecommunications Union, to join such figures as André-Marie Ampère, Alexander Graham Bell, Michael Faraday, and Guglielmo Marconi.

Bibliography

Lawrence Lessing, Man of High Fidelity: Edwin Howard Armstrong (1956; reissued 1969), is a definitive biography.

W. Rupert MacLaurin and R. Joyce Harman, Invention & Innovation in the Radio Industry (1949, reprinted 1971);

Don V. Erickson, Armstrong's Fight for FM Broadcasting: One Man vs Big Business and Bureaucracy (1973), provide historical background.

Source: Britannica Online

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