Precision telegraph relay
date: label: date made
content: ca 1914
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 the Estate of John H. Hammond, Jr., thru The National Shawmut Bank of Boston
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.327513
label: catalog number
content: 327513
label: accession number
content: 266066
objectType: label: Object Name
content: relay
label: Object Name
content: telegraph relay
label: Other Terms
content: telegraph relay; Radio
physicalDescription: label: Measurements
content: overall: 6 1/2 in x 5 1/4 in x 5 1/4 in; 16.51 cm x 13.335 cm x 13.335 cm