Western Electric telegraph relay

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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.
This telegraph repeater was made by Western Electric Manufacturing Company in Chicago. Better know for their long association with the Bell Telephone System, they also fabricated other electrical devices. The theory and operation of telegraph systems constituted a part of standard physics and electrical engineering curricula in the late 19th and early 20th centuries, as at Oberlin College. The Physics Department at that school donated this repeater to the new National Museum of History and Technology in 1964.
Currently not on view
Western Electric
Physical Description
wood (overall material)
metal (overall material)
brass (overall material)
plastic (overall material)
overall: 4 in x 9 1/2 in x 5 1/2 in; 10.16 cm x 24.13 cm x 13.97 cm
ID Number
accession number
catalog number
Credit Line
from Oberlin College, Dept. of Physics, thru David L. Anderson
See more items in
Work and Industry: Electricity
Telegraph Relays & Repeaters
Data Source
National Museum of American History


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