Dumont 3" resonoscope, developmental model
date: label: date made
content: ca 1936
name: label: maker
content: DuMont Company
notes: label: Description (Brief)
content: Dumont X-474. Based upon a patent of Lester B. Holmes, this instrument was designed to provide a visual method for tuning a musical instrument. A specially designed cathode ray tube oscillograph is employed with twelve electrically-driven tuning forks based upon the standard tempered chromatic scale. (A = 440 cps.) The tuning forks are used to synchronize an oscillator that in turn provides the horizontal sweep circuit for the CRT. A voltage amplifier is used to pick up music or any single musical tone by use of a crystal microphone and the output of this amplifier is fed to the vertical plates of the CRT. This gives a visual picture of note wave forms under observation. If the musical note is of the same pitch as the predetermined tuning forks standard, the wave form will appear to stand still on the CRT screen. The wave form will appear to move left if the note is flat and move right if the note is sharp. A musician can thus tune their instrument by an accurate visual method. Sweep circuit employs a type 885 sawtooth oscillator. The CRT is a 3" Dumont 34-XH. References: Dumont Oscillographic - April 1937; US Patent 2153800.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Ethel DuMont
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.327749
label: catalog number
content: 327749
label: accession number
content: 270106
label: maker number
content: X474
label: patent number
content: 2153800
objectType: label: Object Name
content: resonoscope
label: Object Name
content: resonoscope, dumont, sn x-474
label: Object Name
content: musical instrument tuner
physicalDescription: label: Measurements
content: overall: 12 in x 7 in x 13 in; 30.48 cm x 17.78 cm x 33.02 cm