NBC / RCA "Velocity" Ribbon Microphone
date: label: Date made
content: 1931
label: date made
content: ca 1931
label: date made
content: ca 1931
label: date made
content: ca. 1931
name: label: maker
content: RCA Corporation
notes: label: Description
content: RCA / NBC "velocity" ribbon-type radio broadcasting microphone, inscribed "NBC," on the base, with the numbers "31-4" and "405530A4;" attached cord. A narrow, corrugated ribbon of aluminum alloy (without diaphragm) is caused to vibrate in the field of a permanent magnet by sound frequencies in its field of response. A current is generated in the ribbon corresponding exactly to the frequency and amplitude of the original sound. Bi-directional response field 90 degrees front and back. Diamond shaped perforated bronze metal case with NBC plates on black base. Marks cast inside of base 91-A.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from National Broadcasting Company, Inc.
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.311452
label: catalog number
content: 311452
label: accession number
content: 148157
objectType: label: Object Name
content: Microphone
label: Object Name
content: condenser microphone
physicalDescription: label: Measurements
content: overall: 11 1/8 in x 7 in x 7 in; 28.2575 cm x 17.78 cm x 17.78 cm