Bell telephone magazine (1922) (14569448138)

Identifier: belltelephonemag16amerrich (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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WIDE BAND LATTICE FREQUENCY Fig. 6. Using Crystals Alone, above, Only a Very Narrow Pass Band Can beObtained, but the Addition of Inductance, in Series with the Crystal, Makes ItPossible to Widen Out the Band Over Fifteen Fold. filters with and without the added inductances are shown withtheir characteristics in Figure 6. Further studies by Mason indicated that the inductances inthe side and lattice arms could be wound on the same core andplaced in the side arms as indicated in Figure 7, which is aschematic of the actual filter used in the coaxial cable system. 1 Space does not permit a full explanation of this and other steps in the designof the network. The reader is referred to Masons original paper in the Bell SystemTechnical Journal, July, 1934. 34 THE EVOLUTION OF THE CRYSTAL WAVE FILTER A bridging resistance was also inserted between the sectionsto help in sharpening the cut-off. In addition to these modifi-cations, the circuit finally evolved contains added capacitancesin mult

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1922

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