08/13/04
Tom Lewis, Empire of the Air: The Men Who Made Radio, Harpercollins, 1991. Related audio and video cassettes available.
Although telegraphy, by wire, was an increasingly important enterprise, especially after the first trans-Atlantic telegraph cable became operational in 1866, communication through electrical means occupied the attention of relatively few electrical engineers.
Empire of the Air tells the stories of three of the men who developed radio in the United States and, thereby,
In the process, electrical engineering became focussed predominantly on generation, transmission and distribution of electronic signals (information) rather than on generation, transmission and distribution of electric power.
Lee De Forest invented the audion, the first device capable of amplifying electric signals. The audion, known as the triode vacuum tube in the United States and as the valve in England, is the ancestor of the transistor, the most common contemporary amplifying device for signals. De Forest earned a Ph.D. in physics from Yale University under the tutelage of Prof. Josiah Willard Gibbs, recognized internationally for conceiving and developing statistical mechanics, the theoretical basis of deriving and understanding the results of thermodynamics from principles of physics and statistics.
Despite what should have been a strong technical background, De Forest evidently failed for many years to recognize the audion's capability for amplification. Instead, he saw it merely as a means of detecting the presence (or absence) of radio signals and, thereby, of distinguishing the dots and dashes of telegraphic Morse code. Perhaps even more incredibly, De Forest appears not even to have understood the principles of operation for his audion.
De Forest, however, was among the earliest people to comprehend the importance of radio for broadcasting information. Originally, radio was called wireless, short for wireless telegraphy. That terminology reflected the use of radio, like the telegraph, for point-to-point communication. Guglielmo Marconi pioneered wireless telegraphy. For point-to-point to communication, wireless telegraphy offered two advantages over conventional telegraphy by wire:
De Forest saw clearly a much grander application of radio in broadcasting -- sending information from one point to many points rather than simply from one point to another. He transmitted the first news broadcast in 1916 and was among the first to broadcast music. Soon, he began establishing and selling stock in a series of broadcast companies. His companies never succeeded for long, however. Indeed, De Forest was indicted for fraud by one of his companies, although only his partners were convicted in the end. Apart from claims of fraud brought against him, De Forest earned a reputation in the technical community for stealing the ideas of others and claiming them as his own.
One of De Forest's bitterest conflicts was with Edwin Howard Armstrong, the electrical engineer who first developed and published a clear explanation of the operation of De Forest's audion. Specifically, Armstrong showed that the audion not only could detect radio signals, but could amplify them, as well. Moreover, Armstrong demonstrated an oscillator circuit in which the audion generated signals instead of detecting or amplifying them. Thus, he showed how the audion could be used to transmit signals as well as to receive them. De Forest maintained that he had understood these concepts all along but had simply neglected to file the relevant patent applications promptly. His belated patent applications initially were rejected, however, and in defending them, he demonstrated, in the opinion of the electrical engineering community, a surprisingly poor understanding of the operation of the audion, the device he had invented. After the initial victories, Armstrong stubbornly refused to license the patents to De Forest. De Forest then persisted in the courts and, years later, won a long legal battle by means of what Armstrong and most of the electrical engineering community believed to be a legal technicality. Armstrong and De Forest became bitter enemies. The electrical engineers demonstrated their high regard for Armstrong by later electing him president of the Institute of Radio Engineers (IRE), the second predecessor of the IEEE.
Armstrong's contributions did not end with expanded understanding and application of the audion. He conceived the superheterodyne receiver, a receiver that not only produced useful output from extremely weak signals, but required fewer tuning adjustments than previous approaches. The trick is that most of the amplification in a superheterodyne receiver occurs in amplifiers that operate at a fixed frequency and hence require no complex tuning adjustments. The superheterodyne approach is the basis of essentially all contemporary receivers, including those for AM and FM radio, television, satellite broadcasts and cellular telephones.
David Sarnoff began his career in radio as a telegraph operator for the American Marconi Company. He gained early fame as one of the telegraph operators who relayed messages from survivors of the Titanic disaster. (In later years, he shamelessly embellished the truth by claiming to be the only telegraph operator on duty at American Marconi during that time.) Blessed (or cursed) with uncommon talent, energy, determination and unbridled ambition, Sarnoff moved quickly up the ranks at American Marconi. In contrast to De Forest and Armstrong, Sarnoff had little technical background and even less formal education. Over the years, however, he proved again and again to be a prescient visionary. While at American Marconi, for example, he envisioned and proposed the concept of radio broadcasting, perhaps even earlier than De Forest. His superiors, however, showed no interest.
When Sarnoff caught a vision, he demonstrated a knack, which included ruthlessness and tenacity as components, for making his visions become reality. After American Marconi was taken over by the newly founded Radio Corporation of America ( RCA) and Sarnoff became its leader, he determined to implement his vision of broadcasting. More quickly and more clearly than anyone else, he identified two key factors necessary for the success of commercial broadcasting:
Before Sarnoff, programming had been amateurish and uneven in quality. Before Sarnoff, receivers were sophisticated scientific instruments designed to be operated by technically sophisticated people. After Sarnoff, programming became more professional and receivers became consumer products rather than scientific instruments.
Working in cooperation with RCA, Armstrong began to develop FM (frequency modulation) broadcasting. The FM approach achieved less noise (static) and much better audio quality, especially important for broadcasting music, than conventional AM (amplitude modulation) broadcasting. Initially, Sarnoff supported Armstrong's work on FM. Soon, however, Sarnoff became fascinated with the development of television and directed support to it instead of to FM.
Not surprisingly, this change angered Armstrong, especially when Sarnoff took action to thwart the development of FM to prevent possible competition with television for public interest and support. The feelings intensified when the Federal Communications Commission (FCC) specified FM as the means for transmitting the audio part of television signals and Sarnoff refused to pay royalties to Armstrong because, claimed Sarnoff, RCA had its own patent rights to FM. After some wrangling, Sarnoff offered to buy Armstrong's FM patents for RCA, but Armstrong refused. He wanted to license his patents to RCA, and others, for fee, not to sell them. Even friends concluded Armstrong's stubbornness constituted a major obstacle to reaching a compromise.
As the patent fight grew increasingly bitter, Armstrong became overwhelmed by the amount and quality of legal resources that a corporate giant like RCA could muster against him and concluded that his cause was lost. He became despondent and, uncharacteristically, struck his wife. Soon afterwards, he jumped out of a tall building and killed himself. After Armstrong's death, his wife pursued the patent fight. Ironically, the courts ultimately ruled in favor of Armstrong.
Today, Armstrong's FM is the predominant means of broadcasting audio and his superheterodyne design is the basis of essentially all contemporary receivers. The system for contemporary television is that originally developed by RCA under Sarnoff's direction and NBC remains an important force in television programming. The research laboratory that Sarnoff established at RCA is now a separate entity ( http://www.sarnoff.com/ ). In 1986, RCA was absorbed by its former competitor, GE, which was founded by Thomas A. Edison. In 1988, the consumer products parts of GE and RCA became part of Thomson. Thomson, a European company founded by electric utility pioneer Elihu Thomson, merged with Thomas Edison's company to form the original GE. Mergers and acquisitions are nothing new. The direct descendents of De Forest's audion, transistors, have found application not only in radio and television broadcasting, but in electronic communication, computing and in electronic control of an unimaginable variety of processes.
None of these three men receives the popular recognition that they so frantically sought. All would likely find small consolation in having helped change the face of electrical engineering.
The following Web sites deal with the history of radio and broadcasting: