Vibroplex Telegraph Key
name: label: maker
content: Martin, Horace G.
notes: label: Description (Brief)
content: Telegraph keys are electrical on-off switches used to send messages in Morse code. Horace G. Martin patented a practical semi-automatic telegraph key in 1903 and his company dominated the market for these devices. Keys like Martin's "Vibroplex" automatically produced rapid morse code dots by using a weighted pendulum to quickly make and break contact in the electrical circuit. The operator would make the dashes manually but could send much faster than with an ordinary key.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Telegraph Keys
label: See more items in
content: Communications
creditLine: label: Credit Line
content: from J. Vanderhoof
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.315160
label: catalog number
content: 315160
label: accession number
content: 217659
objectType: label: Object Name
content: sending key
label: Object Name
content: telegraph key
label: Other Terms
content: telegraph key; Radio
physicalDescription: label: Physical Description
content: iron (overall material)
label: Physical Description
content: copper (overall material)
label: Physical Description
content: slate (overall material)
label: Physical Description
content: plastic (overall material)
label: Measurements
content: overall: 2 1/2 in x 3 1/2 in x 8 in; 6.35 cm x 8.89 cm x 20.32 cm