Telegraph Transmitter
name: label: maker
content: J. H. Bunnell & Co.
notes: label: Description (Brief)
content: Telegraph lines could carry more than one message at a time if designed cleverly. In 1868, Joseph Stearns devised a method of sending two messages simultaneously on a single line. Called a duplex telegraph, Sterns' invention instantly doubled the capacity of a telegraph line. Each station had a transmitter and receiver on the line. This Sterns duplex transmitter sent a series of electrical pulses through the line. Short pulses made a dot, slightly longer pulses made a dash. The sequence of dots and dashes represented letters and numbers. The circuit was designed in such a way that this transmitter activated the receiver at the other end of the line but not the receiver next to the sending operator. The active receiver mades a loud “click” when it struck a crossbar and the operator translated the pattern of sounds into the original language.
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.331924
label: catalog number
content: 331924
label: accession number
content: 294351
label: collector/donor number
content: 100-845
objectType: label: Object Name
content: telegraph transmitter
label: Object Name
content: duplex transmitter
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: rubber (overall material)
label: Physical Description
content: steel (overall material)
label: Measurements
content: overall: 4 1/8 in x 8 1/2 in x 4 3/4 in; 10.4775 cm x 21.59 cm x 12.065 cm