Telegraph Sounder and Resonator

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Description (Brief)
Telegraph sounders convert electrical pulses into audible sounds and are used to receive Morse code messages. The message travels as a series of electrical pulses through a wire. Short pulses make a dot, slightly longer pulses make a dash. The sequence of dots and dashes represent letters and numbers. The pulses energize the sounder’s electromagnets which move a lever-arm. The arm makes a loud “click” when it strikes a crossbar and the operator translates the pattern of sounds into the original language. A resonator like this wall-mounted unit was used to amplify the sound, making it easier for an operator to hear his or her own sounder when working in a room filled with these devices.
Currently not on view
date made
ca 1913
Western Electric
Physical Description
wood (overall material)
brass (overall material)
rubber (overall material)
iron (overall material)
sounder: 4 1/2 in x 5 1/2 in x 3 in; 11.43 cm x 13.97 cm x 7.62 cm
resonator open: 15 in x 7 in x 26 1/2 in; 38.1 cm x 17.78 cm x 67.31 cm
ID Number
accession number
catalog number
Credit Line
from Western Union Corporation
See more items in
Work and Industry: Electricity
Telegraph Sounders
Data Source
National Museum of American History


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