Radio, miracle of the 20th century ... a story of human achievement that stands unrivalled in the history of humanity, together with a colorful portrayal, giving a broad, general view of the whole subject of wireless telegraph and telephone and its marvelous development (1922)
Drinker, Frederick E. [from old catalog], Lewis, James G., [from old catalog] joint author · [Philadelphia, Printed by National publishing co.] · leaf 331
variation inthe current being identically similar in amplitude andfrequency to the sound waves which produce it. Thisvariation in direct current is usually converted, by meansof a transformer, into a variation in alternating currentwhich is similar to the variation in direct current. Thevariation… … * T i alternating current which causes them. As this identicalsimilarity of amplitude and frequency has been main-tained throughout the complete cycle, the sound wavesproduced by the receiver are identical with those origin-ally produced by the voice. The series of events outlinedabove are…
Radio
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
