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Telegraph Key

Telegraph Key

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Description (Brief)
Telegraph keys are electrical switches used to send coded messages that travel as a series of electrical pulses through a wire. Due to special difficulties in sending pulses through long underwater cables, so-called double-current keys were used. Instead of the short dots and long dashes of land-line telegraphs, submarine telegraphs sent positive pulses and negative pulses that made the receiver move right or left. The operator pressed one lever on the key to send a positive pulse and another to send a negative pulse. The code consisted of the sequence of left and right movements recorded on a paper tape.
Location
Currently not on view
Object Name
submarine telegraph key
telegraph key
cable key
Physical Description
brass (overall material)
metal (overall material)
plastic (overall material)
fiber (overall material)
Measurements
overall: 2 1/2 in x 4 in x 5 in; 6.35 cm x 10.16 cm x 12.7 cm
ID Number
EM.330279
catalog number
330279
accession number
288763
Credit Line
from ITT World Communications, Inc., thru John Van Ingen
See more items in
Work and Industry: Electricity
Communications
Telegraph Keys
Data Source
National Museum of American History
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