Reginald Fessenden
Reginald Fessenden was born October 6, 1866, in East-Bolton, Quebec, the eldest of the Reverend Elisha Joseph Fessenden and Clementina Trenholme's four children. Elisha Fessenden was a Church of England in Canada minister, and the family moved to a number of postings throughout the province of Ontario.
Radio receiver
In 1901 Reginald Fessenden had invented a better means of accomplishing this. In his "heterodyne receiver" an unmodulated sine wave radio signal at a frequency f" offset from the incoming radio wave carrier f" was applied to a rectifying detector such as a crystal detector or electrolytic detector, along with the radio signal from the antenna. In the detector the two signals mixed, creating two new "heterodyne" (beat) frequencies at the sum f" + f" and the difference f" − f" between these frequencies. By choosing f" correctly the lower heterodyne f" − "f" was in the audio frequency range, so it was audible as a tone in the earphone whenever the carrier was present. Thus the "dots" and "dashes" of Morse code were audible as musical "beeps". A major attraction of this method during this pre-amplification period was that the heterodyne receiver actually amplified the signal somewhat, the detector had "mixer gain".