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A telegraph code is one of the character encodings used to transmit information by telegraphy. Morse code is the best-known such code.Telegraphy usually refers to the electrical telegraph, but telegraph systems using the optical telegraph were in use before that.
A telegraph key, clacker, tapper or morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. [1] Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy .
Cooke and Wheatstone's five-needle telegraph from 1837 Morse telegraph Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske. Electrical telegraphy is a point-to-point text messaging system, primarily used from the 1840s until the late 20th century.
The electric telegraph was slower to develop in France due to the established optical telegraph system, but an electrical telegraph was put into use with a code compatible with the Chappe optical telegraph. The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany in 1848. [1]
A wire signal is a brevity code used by telegraphers to save time and cost when sending long messages. The best-known code was the 92 Code adopted by Western Union in 1859. The code was designed to reduce bandwidth consumption over telegraph lines, thus speeding transmissions by utilizing a numerical code system for frequently used phrases.
A telegraph sounder is an antique electromechanical device used as a receiver on electrical telegraph lines during the 19th century. It was invented by Alfred Vail after 1850 to replace the previous receiving device, the cumbersome Morse register [ 1 ] and was the first practical application of the electromagnet .
Myer's code remained in use in the US until 1886 when it was replaced by Morse code for flag signals. [63] It came back into use after 1896, [50] but was officially discontinued in 1912 when International Morse code was mandated for all types of visual signaling. Inconsistently, American Morse code was mandated for Army electrical telegraph ...
A telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature. In early telegraphy , magnetos were used to power instruments, while in telephony they were used to generate electrical current to drive electromechanical ringers in telephone sets and activate signals ...