USS Fessenden (DE-142)
She was named in honor of Reginald Aubrey Fessenden, born in Brome County, Quebec, Canada, 6 October 1866. He served as head chemist with Thomas Edison's East Orange, New Jersey, laboratories. In 1890 he began concentrating on electrical engineering, and through the next years made many important inventions and improvements in existing devices. His great contributions in the field of radio (particularly the invention of radio-telephony were of marked benefit not only to the Navy but to all seamen. He died 22 July 1932, at his home on Bermuda.
Heterodyne
In 1901, Reginald Fessenden demonstrated a direct-conversion heterodyne receiver or beat receiver as a method of making continuous wave radiotelegraphy signals audible. Fessenden's receiver did not see much application because of its local oscillator's stability problem. A stable yet inexpensive local oscillator was not available until Lee de Forest invented the triode vacuum tube oscillator. In a 1905 patent, Fessenden stated that the frequency stability of his local oscillator was one part per thousand.