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a simple transmitter of telegraph signals in Morse code; part of Morse telegraph equipment. The telegrapher manipulates a lever, which closes and opens a current-carrying circuit in a manner that corresponds with the transmitted message. The speed of transmission is 70–90 characters per min for regular keys and 120–150 characters per min for speed keys. Telegraph keys are used in radiotelegraph communications featuring manual processing of signals, especially by radio amateurs operating on shortwaves.