Edwin Howard Armstrong


Edwin Howard Armstrong : biography

18 December 1890 – 31 January 1954

Within a few years a majority of households were FM equipped, by the 1980s a majority of cars sold had FM stereo radios and a majority of listening in the U.S. was devoted to FM signals according to the Arbitron rating service. The stereo sound revolution, followed by the programming revolution, accomplished what cleaner and crisper sound alone was unable to achieve, and made FM radio a permanent and important part of the communications landscape.

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"). His work, as important as it was in its own right, was a part of a continuum of progress in communications and electronics that since his time has brought forward color television, the personal computer, the Internet, cable and satellite radio and TV, personal mobile phones, audio, video and computing, digital stereo radio on both the medium wave and VHF-FM bands, and digital high definition television on VHF, UHF, cable and satellite. Armstrong’s FM system was used for communications between NASA and the Apollo program astronauts. He is of no known relation to the well-known Apollo astronaut Neil Armstrong.

After her husband’s death, Armstrong’s estate finally won the case against RCA. Dana Raymond of Cravath, Swain & Moore in New York served as counsel in that litigation. Marion Armstrong became extraordinarily wealthy as a result of FM’s commercial success and acceptance worldwide.

In 1984 Robert Mondlock copyrighted an original screenplay about Armstrong’s life titled "High Fidelity".

Early work

As an undergraduate, and later as a professor at Columbia University, Armstrong worked from his parent’s attic in Yonkers, New York to develop the regenerative circuit, the superheterodyne receiver, and the superregenerative circuit. He studied under Professor Mihajlo Pupin at the Hartley Laboratories, a separate research unit at Columbia University. Thirty-one years after graduating from Columbia he became Professor of Electrical Engineering, filling the vacancy left by the death of Professor J. H. Morecroft. He held the position until his death.

Armstrong contributed the most to modern electronics technology. His discoveries revolutionized electronic communications. Regeneration, or amplification via positive feedback is still in use to this day. Also, Armstrong discovered that Lee De Forest’s Audion would go into oscillation when feedback was increased. Thus, the Audion could not only detect and amplify radio signals, it could transmit them as well.

While De Forest’s addition of a third element to the Audion (the grid) and the subsequent move to modulated (voice) radio is not disputed, De Forest did not put his device to work. Armstrong’s research and experimentation with the Audion moved radio reception beyond the crystal set and spark-gap transmitters. Radio signals could be amplified via regeneration to the point of human hearing without a headset. Armstrong later published a paper detailing how the Audion worked,

something De Forest could not do. De Forest did not understand the workings of his Audion. 

Armstrong’s service as a signal officer in World War I led to his design of the superheterodyne circuit. The discovery and development of the technology made radio receivers, then the primary communications devices of the time, more sensitive and selective. Before heterodyning, radio signals often overrode and interfered with each other. Heterodyning also made radio receivers much easier to use, rendering obsolete the multitude of tuning controls on radio sets of the time. The superheterodyne technology is still used today. There was a dispute regarding who invented superheterodyne radio. Walter Schottky claimed that he had independently invented super heterodyne radio.