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English: Silicon point-contact crystal detector from 1906, invented by Greenleaf Whittier Pickard. The first silicon diode, and one of the first versions of the cat's whisker detector, this was used in early crystal radio receivers during the first few decades of radio. The brass contact point touched the surface of a crystal of silicon to form a crude silicon diode (Schottky diode). Silicon did not require the delicate cat's whisker contact used in later detectors. The flat piece of silicon is embedded in solder in the shallow metal cup at bottom, which can be moved horizontally to try different contact points. There is a helical spring inside the barrel of the device which puts pressure on the contact.
|Source||Downloaded 2010-03-02 from Walter Wentworth Massie, Charles Reginald Underhill (1908) Wireless Telegraphy and Telephony Popularly Explained, D. Van Nostrand Co., New York, p.31, fig.16 on Google Books|
|Author||Walter Wentworth Massie and Charles Reginald Underhill|
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