Greenleaf Whittier Pickard

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Greenleaf Whittier Pickard (February 14, 1877, Portland, Maine - January 8, 1956, Newton, Massachusetts) was a United States radio pioneer.

Pickard was a researcher in the early days of wireless. He experimented with crystal detectors, used in crystal radio receivers. On August 30, 1906 he filed a patent for a silicon crystal detector, which was granted on November 20, 1906.^[1]

Pickard's detector was revolutionary in that he found that a fine pointed wire known as a "cat's whisker", in delicate contact with a mineral produced the best semiconductor effect.

1 Patents
2 Trivia
3 References
4 External links

[edit] Patents

U.S. Patent 796011 - Electrostatic separation
U.S. Patent 796012 - Electrostatic separation
U.S. Patent 827115 - Electrostatic separation
U.S. Patent 827116 - Electrostatic separation
U.S. Patent 836531 - Means for receiving intelligence communicated by electric waves (silicon detector), 1906
U.S. Patent 840802 - Electrostatic separator,1907
U.S. Patent 845316 - Means for receiving intelligence communicated by electric waves (copper sulfate solution detector), 1907
U.S. Patent 876996 - Intelligence intercommunication by magnetic wave component, 1908
U.S. Patent 877451 - Means for receiving intelligence communicated by electric waves (spring-loaded detector contact), 1908
U.S. Patent 886154 - Oscillation receiver (fused zinc oxide detector), 1908
U.S. Patent 888191 - Oscillation receiver (polished silicon detector, 1908
U.S. Patent 904222 - Oscillation detecting means (molybdenite detector), 1908
U.S. Patent 912613 - Oscillation detector and rectifier ("plated" silicon carbide detector with DC bias), G.W. Pickard, 1909
U.S. Patent 912726 - Oscillation receiver (fractured surface red zinc oxide (zincite) detector), 1909
U.S. Patent 933263 - Oscillation device (iron pyrite detector), 1909
U.S. Patent 1104073 - Detector for wireless telegraphy and telephony (looped or humped springy wire detector contact), 1914
U.S. Patent 1118228 - Oscillation detectors (pairs of minerals), 1914
U.S. Patent 1128817 - Valve detector for wireless (vacuum tube with conducting shield to drain static), 1915
U.S. Patent 1185711 - Receiver for wireless telephony and telegraphy (interrupted or switched circuit instead of rectifier), 1916
U.S. Patent 1213250 - Means for receiving intelligence communicated by electric waves (receiving circuit, divided from #836531), 1917
U.S. Patent 1476102 - Optical selection of split mica sheets
U.S. Patent 1561483 - Distinguishing dielectric sheets
U.S. Patent 1676745 - Electrical reactance and method and apparatus
U.S. Patent 1918825 - Extreme loading condenser