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 229
nd C varied. High frequency alternatingcurrent will be obtained from the wires KK but thevoltage and current will be in the order of millionths of avolt or ampere. A meter cannot be used and a deviceknown as a detector is employed which, with telephonereceivers, makes the currents audible.… … Detector Telephones Fig. 4. It should be noted that the scheme of connection is al-most similar to the transmitting set with the one excep-tion that a detector and telephones have been added. The operation has already been explained; the variouswave lengths are obtained by varying the frequency…
Radio
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