. The Bell System technical journal . ction by the fact that they sectionalizecable lines at about 50 mile intervals and open-wire lines at intervals of200 miles or less, and limit the power which can be transmitted fromsection to section. There is some evidence that this tends to limitacoustic shocks. Carrier Telephone Systems.—A third important trend in telephonepractise is the extension in the use of carrier telephone systems forlong circuits and the associated changes in aerial wire constructionpractises. The growth in use of this type of circuit is indicated in 170 BELL SYSTEM TECIIMCAL J
. The Bell System technical journal . ction by the fact that they sectionalizecable lines at about 50 mile intervals and open-wire lines at intervals of200 miles or less, and limit the power which can be transmitted fromsection to section. There is some evidence that this tends to limitacoustic shocks. Carrier Telephone Systems.—A third important trend in telephonepractise is the extension in the use of carrier telephone systems forlong circuits and the associated changes in aerial wire constructionpractises. The growth in use of this type of circuit is indicated in 170 BELL SYSTEM TECIIMCAL JOIRXAL \\g. 5. The carrier systems are much less iiiHuenced by noise iiuluc-lion from power circuits because they occupy a range of frequencies(5000 to 30,000 cycles) in which the harmonic power voltages or cur-rents ordinarily are extremely small. Furthermore, in order to obtaineconomies inherent in the use of large numbers of carrier systems on thesame telephone pole line it has been necessary to design systems of 3-C BH 8v8 Sv£. 3-C 3-C 8v8 6v8 I
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
