differential type telegraph relay-repeater
notes: label: Description
content: 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.
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
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.331980
label: collector/donor number
content: 100-033
label: accession number
content: 294351
label: catalog number
content: 331980
objectType: label: Object Name
content: repeater relay
label: Object Name
content: telegraph relay
physicalDescription: label: Physical Description
content: wood (part: material)
label: Physical Description
content: metal (part: material)
label: Physical Description
content: plastic (part: material)
label: Measurements
content: overall: 3 5/8 in x 9 in x 5 in; 9.2075 cm x 22.86 cm x 12.7 cm