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pole-changer transmitter

pole-changer transmitter

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Description
Telegraph relays amplified electrical signals in a telegraph line. Telegraph messages traveled as a series of electrical pulses through a wire from a transmitter to a receiver. Short pulses made a dot, slightly longer pulses a dash. The pulses faded in strength as they traveled through the wire, to the point where the incoming signal was too weak to directly operate a receiving sounder or register. A relay detected a weak signal and used a battery to strengthen the signal so that the receiver would operate.
Location
Currently not on view
Object Name
telegraph relay
Measurements
overall: 3 3/4 in x 8 1/4 in x 4 3/4 in; 9.525 cm x 20.955 cm x 12.065 cm
ID Number
EM.331785
catalog number
331785
accession number
294351
collector/donor number
100-846
Credit Line
from Western Union Corporation
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Work and Industry: Electricity
Communications
Data Source
National Museum of American History
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