Rodgers telegraph relay

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 relay appears similar to early units from the 1850s and '60s. The frame is marked "J. Rodgers New York" about whom we have no current information.
Currently not on view
Object Name
telegraph relay
Rodgers, J.
Physical Description
brass (overall material)
wood (overall material)
aluminum (overall material)
overall: 5 1/2 in x 8 1/4 in x 6 3/4 in; 13.97 cm x 20.955 cm x 17.145 cm
place made
United States: New York
ID Number
catalog number
accession number
See more items in
Work and Industry: Electricity
Telegraph Relays & Repeaters
Data Source
National Museum of American History, Kenneth E. Behring Center


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