Edwin Howard Armstrong (1890–1954)

Edwin Howard Armstrong perfected the circuitry that made early radio broad casting feasible and pioneered a whole new approach to the technology of broadcasting when he developed wideband FM transmission. Even though solid-state circuits and digital equipment have replaced the vacuum tubes and wires of early radio, without Armstrong’s circuitry it is unlikely that radio (and later television) broadcasting would have become such a ubiquitous part of modern life. Armstrong’s inventions brought him personal wealth and professional recognition, but they also embroiled him in epic legal battles that eventually resulted in personal tragedy.

Like many boys of his time and age, Howard Armstrong, as he was called, fell under the spell of wireless transmission, which in the 1890s had been pioneered by Guglielmo Marconi, barely out of his boyhood himself when he made his first breakthroughs. Armstrong showed an inclination toward mechanical facility in his youth but it was not until his high school years that he seriously took up amateur experimentation in radio transmissions and he was still an undergraduate at Columbia when he undertook an investigation into the audion tube, a modification devised by Lee de Forest of the vacuum tube, which enhanced the reception of radio signals. Armstrong not only discovered how it worked (something its inventor had been unable to do or explain) but also discovered that it was more than a detector of radio waves; it was also an amplifier of them, thus paving the way for clearer and more reliable reception of transmissions over long distances.

In September of 1912, he developed a circuit that confirmed his theoretical breakthrough, allowing listeners to hear far-flung Marconi stations with great clarity and without headphones. The process Armstrong devised is known as feed-back or regeneration, and his circuit is known as a regenerative circuit. He also discovered that the tube could serve as a transmitter of radio signals, a discovery that would change the nature of the machinery needed to transmit signals. As historian Tom Lewis observes, “What formerly required a machine the size of a squash court to produce [continuous radio waves] now took a comparatively small vacuum tube.”

Armstrong’s next technical break-through occurred while he was on active duty in the Army after the United States entered the Great War (World War I) in 1917. Commissioned as a captain in the signal corps in France, Armstrong helped build aircraft communications systems and set himself to the problem of detecting high-frequency radio waves, which the Germans were suspected of using for secret communications. His work resulted in the principle he named “superheterodyne” tuning, a process that allowed more precise tuning of radio sets to a wide range of frequencies and that eventually replaced primitive methods in use up to that time.

Radio technology expert Edwin Armstrong developed the static-free, broadband broad-casting technology called frequency modu-lation, or FM.

Radio technology expert Edwin Armstrong developed the static-free, broadband broadcasting technology called frequency modulation, or FM. (© Bettmann/CORBIS)

The patents Armstrong was granted for these discoveries brought him great wealth and professional honors, but they also became the subjects of protracted litigation that would consume a good deal of Armstrong’s time and resources. The first of these, over the regenerative circuit, became the longest running patent suit in history. Armstrong had belatedly filed his patent application for regeneration in October 1913. De Forest, who was a veteran of patent wars already, nonetheless filed a patent in 1915 for an “oscillating audion” that had similar properties to Armstrong’s regenerative circuit, claiming he had discovered its properties in 1912. Others also made claims to having discovered regeneration.

In the ensuing legal battle (delayed by the advent of World War I, when all patent suits were suspended), Armstrong sued de Forest for patent infringement, and his claims to priority in the regenerative circuit were upheld in the lower courts and also in the parallel proceedings within the patent office that was investigating the multiple claims alongside the lawsuit. De Forest nonetheless pressed his claims and challenged the ruling of the patent office in a new lawsuit. In this case, his claims were upheld, based on the appeals court’s misreading of the applicable precedents, according to Lewis, leaving Armstrong no recourse but to appeal to the Supreme Court in 1928. But the court upheld De Forest’s position. Stunned by the irrationality of the court’s ruling, Armstrong sought an opportunity to vindicate his claims.

The legal situation was made more complex by the involvement of the Radio Corporation of America (RCA), which had interests in Armstrong’s patents as well as de Forest’s. The American Marconi Company had originally licensed Arm-strong’s circuits in 1913, based on the recommendations of its young rising executive David Sarnoff who had befriended Armstrong, while American Telephone and Telegraph (AT&T) had acquired de Forest’s patents. Armstrong’s patents later came under the control of RCA, the successor to the Marconi Company founded by General Electric; de Forest’s patents came under RCA’s control when AT&T, an erstwhile partner with GE in RCA, left the “radio group” after an internal dispute over the control of commercial broadcasting. (See article on David Sarnoff.)

By the late 1920s, radio broadcasting was flourishing, especially for RCA and for its new broadcast arm, the National Broadcasting Company. As the company grew, its stock soared in value in the frenzy of speculation of the 1920s stock boom, and Armstrong, whose patent licenses with the company made him the largest individual shareholder, became extremely wealthy—and he had the prescience or the good luck to cash out his holdings before the market crashed in 1929. During this time, he married David Sarnoff’s secretary, Marion MacInnis. They remained childless after Marion underwent a hysterectomy on their honeymoon trip to Florida, which Armstrong continued alone, leaving Marion behind at the Johns Hopkins Medical Center in Baltimore.

In the early 1930s, Armstrong’s legal quest took a new turn when he purchased a majority interest in a small company supplying equipment to amateur radio operators. RCA had sued the company for infringement of de Forest’s patents, which it now owned, and Armstrong saw this suit as a way to vindicate his patent claims. RCA (standing in for de Forest) prevailed at the circuit court level but Armstrong’s company, Radio Engineering Laboratories (REL), won a decision in the court of appeals. Despite private acknowledgement of Armstrong’s claims from many within RCA, including its general counsel and Sarnoff himself, the company nonetheless appealed to the Supreme Court. Here, in 1934, the de Forest claims to priority were once again upheld, a decision that caused an outpouring of criticism in the technical community. Armstrong’s lawyers petitioned for a stay but the court upheld its previous decision. Thus, legally, and finally, de Forest could claim to be “Father of Radio,” the title he later used for his autobiography. Many in the engineering community, however, continued to regard Armstrong as the true parent; in 1934, shortly after the Supreme Court ruling, the Institute of Radio Engineers refused Armstrong’s attempt to return the Medal of Honor the Institute had given him in 1918 for the invention of regeneration.

A nearly 20-year patent war heard by 13 courts and 30 judges, as Lewis notes, would seem enough for one man’s life—and it took its toll on Armstrong mentally and financially. (He had also been challenged on the invention of superheterodyne tuning.) He nonetheless was to face yet another protracted battle in the courts over the development of FM broadcasting. While he pressed his legal claims, Armstrong undertook a new area of investigation, a device that could eliminate the biggest problem confronted by radio transmissions: static. His search for a solution consumed him for the next half-decade and resulted in the development of broadband FM transmission. Theoretical work seemed to argue that FM was a dead end as far as broadcasting was concerned, that it yielded no advantage over AM, as one prominent AT&T researcher claimed.

Armstrong, however, believed otherwise, taking a novel approach that focused on the bandwidth of the radio wave as well as on its frequency. In 1933, he began demonstrating the results of his work, a system that brought in voice and music and other sounds with startling clarity and fidelity and without static. David Sarnoff declared Armstrong’s system a “revolution” when he first heard it demonstrated, but after providing some initial support for Armstrong’s early experimental broadcasts by allowing Armstrong to use RCA space in the new Empire State Building, he remained cool to his friend’s innovations, believing that the future lay in television rather than in a radical retooling of radio broadcasting that FM would require. (Today FM and AM exist side by side, but in the 1930s it was no doubt assumed that it was either one or the other.)

Armstrong, who from an early age had exhibited an independent, determined, and obstinate streak (some considered him arrogant), decided to go out on his own to demonstrate the superiority of his new system. He eventually was granted a license for an experimental station that he built on the Palisades in New Jersey, where he erected a giant antenna (still in use). But RCA was lobbying against his work at the newly formed Federal Communications Commission and Armstrong suspected that its engineers were working to invalidate or circumvent his patents. Armstrong licensed his systems to others and a small network of FM stations was launched in New England, which also demonstrated another feature of FM: the capability of its signals to be successfully relayed wirelessly.

By the time World War II began, Armstrong’s system was being adopted on a wider scale, and he had negotiations with RCA to license it, although ultimately they could not come to terms. Matters remained at this impasse when war was declared and the radio industry redirected itself to the war effort. Armstrong’s FM system was adopted by the military for field communications, and Armstrong waived his financial interest in his patents until after the war; he spent the war researching improvements in radar (his attorney persuaded him to accept a government contract to offset the loss of income his waiver of royalties had caused).

As the war neared its end, the FCC began hearings on allocation of spectrum space for postwar developments in broadcasting including FM and television. RCA used its influence to secure for television signals the portion of the spectrum previously allocated to FM, thus requiring a major retooling of all the stations already on the air and rendering obsolete all the radio sets already in use. Additional moves by the FCC, supported by the other major broadcasters (especially CBS), cut the power at which FM stations were allowed to operate and allowed those broadcasters who owned both AM and FM stations (i.e., the networks) to broadcast the same programming over both, all decisions that favored the big broadcasters and hobbled the development of FM as an alternative to AM broadcasting. RCA in the mean-time had used the war years to develop alternatives to Armstrong’s FM circuits.

In 1948, Armstrong, facing dwindling financial resources from his lack of income during the war and use of his own money in developing FM as an independent inventor, filed suit against RCA for infringement of his FM patents and for its efforts to block his invention. The preliminary procedures leading up to the trial consumed several years and Armstrong’s resources began to dwindle even further. In 1953, his lawyers, realizing that the case could drag on and on and not be fully resolved until the early 1960s, began working on an out-of-court settlement proposal. After nearly a year of negotiations, the process broke down; RCA refused to guarantee more than $200,000 (Armstrong sought $3.4 million) and demanded that Armstrong’s claims of deliberate interference with the development of FM be dropped. Armstrong turned down the offer. Distraught by the developments in the proceedings, Armstrong seems to have had a nervous breakdown in which he assaulted his wife, and some months later he committed suicide by jumping out of his apartment window. David Sarnoff is reputed to have said “I did not kill Armstrong,” when he learned of his former friend’s death.

Armstrong’s suit was resolved in his favor some years after his death and rulings in the 1960s by the FCC undoing some of its prior decisions about power and simulcasting eventually made FM radio a commercially viable technology. Aided also by Armstrong’s last major technical development, multiplexing, which led to stereophonic transmission, FM finally came into its own as a broadcast medium.

—Martin Green


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