Detailed treatment is given to the following: operation of the microphone, transformer and modulator; nature of a sound wave; direct current; alternating current; voice current; carrier wave; and amplification.
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Collection
In ACMI's collection
Credits
Collection metadata
ACMI Identifier
009627
Language
English
Subject categories
Advertising, Film, Journalism, Mass Media & TV → Radio - Receivers and reception
Advertising, Film, Journalism, Mass Media & TV → Radio waves
Communications, Infrastructure, & Transport → Communications - History
Communications, Infrastructure, & Transport → Radio waves
Documentary → Documentary films - United States
Educational & Instructional → Educational films
Educational & Instructional → Instructional
Mathematics, Science & Technology → Amperes
Mathematics, Science & Technology → Radio waves
Sound/audio
Sound
Colour
Black and White
Holdings
16mm film; Access Print (Section 1)