Crystal to crystal detector



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English: A "Perikon" crystal detector, an antique electronic component used in crystal radio receivers around the first decades of the 20th century, from a 1914 book on radio. This was a variant of a cat's whisker detector; instead of using a contact between a crystal and a metal wire, it used a contact between two crystals. The crystals consisted of a piece of bornite (Cu5FeS4) mounted in the adjustable holder (right), and 6 pieces of zincite (zinc oxide, ZnO) mounted on the round carousel (left). The bornite crystal was moved forward until it just touched one of the zincite crystals. This created a crude semiconductor diode, which rectified the radio signal in the receiver, extracting the audio modulation (sound) signal from the radio frequency carrier wave. Multiple zincite crystals were provided because the zincite was vulnerable to damage from excess current surges from the antenna due to atmospheric electricity. This type of detector, invented by American radio pioneer Greenleaf Whittier Pickard and trade-named "Perikon" which stood for "PERfect pIcKard cONtact" was more stable and less sensitive to vibration than the common galena detector.
Date 1914(1914)
Source Downloaded 2009-11-08 from Alfred Powell Morgan (1914) Wireless Telegraph Construction for Amateurs, 3rd Ed., D. Van Nostrand Co., New York, p.198, fig.162 on Google Books
Author Alfred Powell Morgan
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Public domain in USA - published prior to 1923 in USA


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