English: A crystal detector, an obsolete electronic component used as a demodulator in crystal radios, displayed at the SPARK Museum of Electrical Invention, Bellingham, Washington, USA. This was a sophisticated model from 1919 used in military wireless telegraphy stations. It consisted of a point made of antimony mounted on a leaf spring, which pressed against a piece of silicon mounted in a cup with fusible alloy. Since only certain sites on the silicon crystal functioned as rectifying junctions, the silicon was mounted on an adjustable "stage" which could be moved in two horizontal directions by the micrometer knobs at right, to find a sensitive spot. The silicon detector was invented in 1906 by Greenleaf Whittier Pickard. It was used in receivers in military and shipboard wireless stations because it's sturdy contact could not be jarred loose by vibrations from waves or gunfire as easily as the delicate cat whisker detectors used in amateur stations.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse
Captions
A silicon crystal detector, an antique radio component