Telegraph Sounder and Resonator

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
Object Name
telegraph resonator
telegraph receiver
telegraph sounder
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
Telegraph Sounders
See more items in
Work and Industry: Electricity
Telegraph Sounders
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
from Western Union Corporation
Additional Media

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