Ralph Hartley (nonfiction)
Ralph Vinton Lyon Hartley (November 30, 1888 – May 1, 1970) was an electronics researcher.
He invented the Hartley oscillator and the Hartley transform, and contributed to the foundations of information theory.
Hartley was employed at the Research Laboratory of the Western Electric Company. In 1915 he was in charge of radio receiver development for the Bell System transatlantic radiotelephone tests. For this he developed the Hartley oscillator and also a neutralizing circuit to eliminate triode singing resulting from internal coupling. A patent for the oscillator was filed on June 1, 1915 and awarded on October 26, 1920.
During World War I Hartley established the principles that led to sound-type directional finders.
Following the war he returned to Western Electric. He later worked at Bell Laboratories. He performed research on repeaters and voice and carrier transmission and formulated the law "that the total amount of information that can be transmitted is proportional to frequency range transmitted and the time of the transmission." His 1928 paper is considered as "the single most important prerequisite" for Claude Shannon's theory of information.
In spite of his illness during most of the 1930s, Hartley had formed a theoretical and experimental research group at Bell Laboratories starting in 1929 to investigate nonlinear oscillations and what later became known as parametric amplifiers. This research was mostly parallel to the work being done at the same time in Soviet Russia by Leonid Mandelstam and in Europe by Balthasar van der Pol.
After about 10 years of illness he returned to Bell Labs in 1939 as a consultant.
During World War II he was particularly involved with servomechanism problems.
He retired from Bell Labs in 1950 and died on May 1, 1970.
His legacy includes the naming of the hartley, a unit of information equal to one decimal digit, after him.
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External links:
- Ralph Hartley @ Wikipedia