File:Bell telephone magazine (1922) (14753572034).jpg

Identifier: belltelephonemag23amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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accomplished by the use ofhigh-frequency currents which arecommonly said to carry the tele-phone conversation. As applied to power-line carrier,this means, in non-technical terms,that a high-frequency telephone cur-rent, carrying conversation, canhitch-hike a ride along an electricpower line, hop off the power line atan appointed spot and onto a pair oftelephone wires running into thecustomers premises, and thus reachthe telephone, over which conversa-tion takes place in no way different—to the speaker—from normal tele-phone usage. Electronic apparatus which createsthe high-frequency current and, whena person is speaking into the tele-phone, varies or modulates it insuch a way that it can carry the con-versation, is installed in or near the central office and on the customerspremises. The high-frequency tele-phone currents hop on and off thepower line by means of carrier coup-lers installed on the power-line pole.These couplers do not permit thepower current to pass; but the tele-
Text Appearing After Image:
Spans averaging from 350 to 450 feet, using high-strength steel wire, materially reduce construction costs phone carrier currents, being of veryhigh frequencies, can pass over thepower line simultaneously with thepower currents, without any mutualinterference, whereas this could notbe done if ordinary telephone currentswere used. 120 Bell Telephone Magazine WINTER

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