Brown drum-type cable relay
date: label: date made
content: ca 1900
name: label: maker
content: S. G. Brown, Ltd.
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: Description
content: This unit is a drum relay specially made for use in submarine telegraphy. Sending signals through underwater cables introduces electrical effects not seen in landline telegraphy. The early cables were also limited by the long distances over which the pulses traveled since relays capable of operating on the ocean floor had not yet been developed. This drum recorder has a wood and glass cover. Unit is mounted on a wooden base. Multi-tap and rotary switches on front, connector panel with 11 posts on the left side. Nameplate reads: "Drum Cable Relay / Patent 1434-1899 / S. G. Brown Ltd. / Acton, London. W. / No. 50". Unit appears to be intact and complete.
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.294351.026
label: accession number
content: 294351
label: catalog number
content: 294351.026
objectType: label: Object Name
content: relay
label: Object Name
content: submarine telegraph component
label: Object Name
content: submarine telegraph relay
label: Object Name
content: telegraph relay
label: Other Terms
content: telegraph relay; Telephones; Components; Telephone and Telegraph; Telephone and Telegraph
physicalDescription: label: Physical Description
content: brass (part: material)
label: Physical Description
content: wood (part: material)
label: Physical Description
content: glass (part: material)
label: Physical Description
content: steel (part: material)
label: Measurements
content: overall: 18 1/2 in x 16 1/2 in x 19 1/4 in; 46.99 cm x 41.91 cm x 48.895 cm