File:Pacific Gas and Electric magazine (1912) (14597387557).jpg

Identifier: pacificgaselectr41913paci (find matches)
Title: Pacific Gas and Electric magazine
Year: 1909 (1900s)
Authors: Pacific Gas and Electric Company
Subjects: Pacific Gas and Electric Company Electric utilities Public utilities
Publisher: (San Francisco, Calif.) : Pacific Gas and Electric Co.
Contributing Library: San Francisco Public Library
Digitizing Sponsor: San Francisco Public Library

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Central Point Station, near Medford, Oregon messages not intended for them. This is be-cause of the fact that dehcate tuning isimpossible in all of these systems. Withoutattempting to explain the why and where-fore of the matter, the following compari-son may serve to illustrate the points of dif-ference in this respect between the sparkand Poulsen systems. If a pistol is fired neara piano, all of the strings will be forced intovibration. When a powerful spark stationis sending, all of the other stations, both largeand small, within a certain radius, are able toreceive the signals on account of theforced oscillations thus set up. If, on theother hand, a C tuning fork is struck andplaced on the strings of a piano, only the Cstrings will respond. This ability to selectonly certain wave lengths and discard allothers, is one of the principal distinguishing features of the Poulsen System. In additionto this, Poulsen signals can only be read byusing Poulsen receiving apparatus, which isvery

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