File:Bell telephone magazine (1922) (14755939352).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:
Figure 10. Distortion of the Shape of Water VV.aves Resulting from the\ariation IX the Velocity of Transmission of the Different Frequency Com-ponents. mm llIIHd .jpmso^. Figure 11. Oscillograph Showing the Distortion of Electrical Waves inTelephone Circuits Resulting from Differences in the Velocity of PropagationAT Dlfferent Frequencies. The upjaer curve shows a compound wave consistin<; ofSOO cycles and 1,600 cycles at the transmitting end of a 600-mile medium heavy loadedrepeatered cable circuit. The lower curve shows the received wave after ampHfication,the distortion resulting in the SOO-cycle component being received first, followed bythe 1,600-cycle component.
Text Appearing After Image:
Figure 12. Distortion of the Electrical W.wis in Telephont; Circuits Re-sulting from Transient Effects. The oscillograph of the transmitted and receivedwaves for a 1,600-cycle impulse sent over a 522-mile medium heavy loaded repeateredcircuit shows the gradual building up and dying out of the received wave. THE TALKING EFFICIENCY OF TELEPHONE CIRCUITS ure 9, for example, shows the electrical efficiency at variousfrequencies in the telephone range of three types of telephonecircuit in cable: first, 8>^ miles of non-loaded 19 gauge cablerepresenting the early art; second, 100 miles of heavily loaded19 gauge cable representing the long distance art of 20 yearsago; and third, 1,000 miles of lightly loaded 19 gauge cablerepresenting the art of today. The modern 1,000 mile circuithas a better characteristic than either of its shorter predeces-sors. Another cause of difference in frequency characteristicsis the difference between the various types of telephone in-struments in use. An inst

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