File:Bell telephone magazine (1922) (14755944502).jpg

Identifier: belltelephonemag12amerrich (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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Text Appearing Before Image:
-tenuation of the bare wires, the effective overall attenuationof the circuit is reduced to only a few decibels so that a whisperin New York is made audible in St. Louis. It is evident thatif the overall result is to be stable, the total amplification mustbe even more stable. The working margin is not only small,but it must remain steady within limits which are still smallerif crosstalk, noise, echoes, or repeater overloading are not toimpair unduly the use of the circuit. It is obvious that thisimposes the requirement of a high degree of stability on eachof the vacuum tubes contributing to the total repeater ampli-fication. Similar considerations apply with regard to the necessity ofnot permitting the tubes to distort the transmitted voice ap-preciably. Vacuum tubes not very far short of perfection areevidently needed if as many as a hundred tubes are to haveopportunity to affect the voice currents in succession along acircuit without finally distorting the voice so as to make it 248
Text Appearing After Image:
FiGiTiE 5. A Group of Two-wire Telephove Repeaters with Accessory Equipment.

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