. The Bell System technical journal . atterncan be synthesized on the computor and the number of components,together with their path differences and relative amplitudes, read directlyfrom the computor dials. This is accomplished by generating four 600-kcsignals, three of which are phase modulated at 60 cycles per second. Thetotal phase deviation and relative signal amplitude are variable. Thefour signals are then summed and displayed in vertical deflection on acathode ray tube having a 60-cycle horizontal sweep. The synthesis of the patterns of Figures 7(b) and 7(c) are shown inFig. 8. The upp
. The Bell System technical journal . atterncan be synthesized on the computor and the number of components,together with their path differences and relative amplitudes, read directlyfrom the computor dials. This is accomplished by generating four 600-kcsignals, three of which are phase modulated at 60 cycles per second. Thetotal phase deviation and relative signal amplitude are variable. Thefour signals are then summed and displayed in vertical deflection on acathode ray tube having a 60-cycle horizontal sweep. The synthesis of the patterns of Figures 7(b) and 7(c) are shown inFig. 8. The upper synthesized pattern is simply a combination of twocomponents with relative amplitudes of and 1 and a path differenceof two feet. The lower pattern consists of the reference component withunity amplitude, a second component with an amplitude of and apath difference of feet, and a third component with an amplitude and path difference of feet. The similarity between the actualand synthesized patterns is Fig. 8—Synthesis of the frequency-sweep patterns of Figs. 7(b) and 7(c).
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
