Also known as crystal radio receiver, galena radio, crystal set
simple radio receiver circuit used mostly for AM reception
Swedish crystal radio from 1922 made by Radiola, with earphones. The device at top is the radio's cat's whisker detector. A second pair of earphone jacks is provided. 1970s-era Arrow crystal radio marketed to children. The earphone is on left. The antenna wire, right, has a clip to attach to metal objects such as a bedspring, which serve as an additional antenna to improve reception.
A crystal radio receiver, also called a crystal set, is a simple radio receiver, popular in the early days of radio. It uses only the power of the received radio wave to produce sound, needing no external power supply. It is named for its most important component, a crystal detector, originally made from a piece of crystalline mineral such as galena. This component is now called a diode.
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