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Type 'C' Form 'A' twin detector crystal radio set, manufactured by British Thomson Houston Ltd. in 1924, kept at the Museum of the radio - Monteceneri (Switzerland) Early radio telegraphy used spark gap and arc transmitters as well as high-frequency alternators running at radio frequencies. The coherer was the first means of detecting a radio ...
So the radio receiving equipment of the time did not have to convert the radio waves into sound like modern receivers, but merely detect the presence or absence of the radio signal. The device that did this was called a detector. The first widely used detector was the coherer, invented in 1890. The coherer was a very poor detector, insensitive ...
In radio, a detector is a device or circuit that extracts information from a modulated radio frequency current or voltage. The term dates from the first three decades of radio (1888–1918). The term dates from the first three decades of radio (1888–1918).
Greenleaf Whittier Pickard (February 14, 1877 – January 8, 1956) was an American electrical engineer and inventor.. While not the earliest discoverer of the rectifying properties of contact between certain solid materials, he was largely responsible and most famous for the development of the crystal detector, the earliest type of diode detector. [1]
The crystal detector was the most successful of many detector devices invented during this era. The crystal detector evolved from an earlier device, [40] the first primitive radio wave detector, called a coherer, developed in 1890 by Édouard Branly and used in the first radio receivers in 1894–96 by Marconi and Oliver Lodge.
Henry Harrison Chase Dunwoody (October 23, 1842 – January 1, 1933) was an American army officer, businessman, and inventor. Known in his own time for his work with the Army's Weather Bureau, he invented the carborundum radio detector in 1906.
Radio pioneer Guglielmo Marconi noticed radio waves were being reflected back to the transmitter by objects in radio beacon experiments he conducted on March 3, 1899, on Salisbury Plain. [9] In 1916 he and British engineer Charles Samuel Franklin used short-waves in their experiments, critical to the practical development of radar. [ 10 ]
A radio signal from the antenna-ground circuit "turns on" the coherer, enabling current flow in the battery-sounder circuit, activating the sounder, S. The coils, L, act as RF chokes to prevent the RF signal power from leaking away through the relay circuit. A radio receiver circuit using a coherer detector (C). The "tapper" (decoherer) is not ...