Telegraph Sounder
date: label: date made
content: ca 1900
name: label: maker
content: J. H. Bunnell & Co.
notes: label: Description (Brief)
content: 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. The date refers to US Patent #538816, issued to Jesse H. Bunnell for an improved "Telegraph Sounder". In this patent, Bunnell claimed to increase the volume of the sound produced by constructing the sounder in such a way as to prevent the weight of the electromagnets from damping out the vibration of the armature. In essence, this acted as a built-in resonator.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Communications
label: See more items in
content: Telegraph Sounders
creditLine: label: Credit Line
content: from Western Union Corporation
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.332407
label: accession number
content: 294351
label: catalog number
content: 332407
objectType: label: Object Name
content: telegraph receiver
label: Object Name
content: telegraph sounder
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: rubber (overall material)
label: Measurements
content: overall: 3 1/2 in x 3 in x 5 1/2 in; 8.89 cm x 7.62 cm x 13.97 cm