Knott coherer radio signal detector with tapper
date: label: date made
content: ca 1908
name: label: maker
content: L. E. Knott Apparatus Company
notes: label: Description (Brief)
content: Wooden board with coherer device, glass tube and filings missing, steel cover loose on piece, cover stamped "Knott Boston." When a radio signal passes through the tube, the metal filings "cohere" or link together, closing an electrical circuit. Tapping the tube causes the filings to disassociate, opening the circuit. This was one of the earliest forms of radio signal detectors.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.320803
label: catalog number
content: 320803
label: accession number
content: 241556
objectType: label: Object Name
content: Detector
label: Object Name
content: coherer tube
label: Object Name
content: coherer
label: Object Name
content: radio receiver
label: Other Terms
content: Detector; Radio
physicalDescription: label: Measurements
content: overall: 1 1/2 in x 7 in x 2 1/2 in; 3.81 cm x 17.78 cm x 6.35 cm