Telegraph Test Unit

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. This small, pocket-sized unit was both transmitter and receiver. It has a leather case and was used by Western Union personnel in the field for testing telegraph lines.

Location: Currently not on view

See more items in: Work and Industry: Electricity, Communications, Telegraph Sounders


Exhibition Location:

Credit Line: from Western Union Corporation

Data Source: National Museum of American History

Id Number: EM.332065Accession Number: 294351Catalog Number: 332065Collector/Donor Number: 100-050

Object Name: pocket telegraphtelegraph test unittelegraph set

Physical Description: leather (overall material)metal (overall material)plastic (overall material)Measurements: overall: 2 3/8 in x 5 3/4 in x 2 7/8 in; 6.0325 cm x 14.605 cm x 7.3025 cm


Record Id: nmah_881798

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