File:Bell telephone magazine (1922) (14776502643).jpg

Identifier: belltelephonemag19amerrich (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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ctady. As amatter of fact, a nip-and-tuck racewas run between the engineers at theBell Telephone Laboratories in NewYork City and those in the GeneralElectric Laboratory here. I cannotrefrain from smiling as I look backupon those days. It seems to me thateach group was making such rapidprogress that they naturally felt aftereach new success that at last theymust necessarily have out-distancedtheir rival—and were a bit disturbedto discover, in due course, that theadversary was still abreast. What the Amplifier Has Done forWire Economy As I have already hinted, the ad-vent of the vacuum tube amplifierradically changed the point of view ofthe engineer regarding long distancetelephone lines. Over a period ofyears he switched from a policy ofextreme parsimony to one almost ofprodigality. Where initially his everythought had been to design his linesso as to minimize the possibility ofenergy loss at every point, he laterchose smaller and smaller line wires 19^0 Transcontinental Panorama 45
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FIGURE 1 Curve A represents long distance circuits possessing the highest attenuation permile. The extreme for 19^0 represents the coaxial cable now being installed.Curve D represents circuits possessing the lowest attenuation per mile after repeatershave been taken into account. Curve B represents the average of all long distancecircuits without repeaters, and Curve C represents the average with repeaters deliberately because the saving oncopper more than compensated forthe additional amplification entailed.Figure 1 will be of interest in thisconnection. On it (plotted to a loga-rithmic scale) the ordinates representloss per mile of circuit. Let us consider curve B first; itshows the average loss per mile oflong distance telephone circuits as ithas varied over the years. You willnote that during the period from 1880to 1915 the average loss per mile fell,the reason being that heavier andheavier copper was resorted to. Then,in 1915, with the advent of repeaters,the circuit attenuation

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