. The Bell System technical journal . DELAY INTRODUCEDI BY LINE DELAY INTRODUCED BY LINE AND EQUALIZER 10 30 50 100 200 500 1000 2000 CYCLES PER SECOND 5000 8000 Fig. 19—Delay-frequency characteristic of 50 miles 16-ga. B-22 cable with and without delay equalizer. LONG DISTANCE CABLE CIRCUIT 591 of transmission through the combination of cable and networks forall frequencies in the band to be transmitted. Fig. 19 shows thedelay characteristic of a section of cable 50 miles in length, with andwithout the delay-equalizing networks. The delay is seen to be main-tained within db milli-second
. The Bell System technical journal . DELAY INTRODUCEDI BY LINE DELAY INTRODUCED BY LINE AND EQUALIZER 10 30 50 100 200 500 1000 2000 CYCLES PER SECOND 5000 8000 Fig. 19—Delay-frequency characteristic of 50 miles 16-ga. B-22 cable with and without delay equalizer. LONG DISTANCE CABLE CIRCUIT 591 of transmission through the combination of cable and networks forall frequencies in the band to be transmitted. Fig. 19 shows thedelay characteristic of a section of cable 50 miles in length, with andwithout the delay-equalizing networks. The delay is seen to be main-tained within db milli-second of a constant value. A schematiccircuit of these networks is shown in Fig. 20. With the greatest. MUTUAL INDUCTANCE BETWEENTHESE TWO WINDINGS THIS COIL IN SAME POT WITHOTHER TWO WINDINGS Fig. 20—Schematic circuit of section of delay equalizer. For a 50-mile equalizer,three kinds of sections are used which vary in the resonant frequency and in thesharpness of resonance. The first three sections are of one kind, the fourth is ofanother and the last seven are of the third kind. length of cable circuits which will be used in this country for programtransmission, this amount of deviation per section is not sufficientto cause objectionable distortion. For a 50-mile section uncorrected,the delay at 8,000 cycles would be milli-second greater than at1,000. A description of these delay-equalizing networks with thetheory of their performance is being presented in another paper sothat a more detailed description is omitted in this paper. Office Wiring Owing to the wide frequency range transmitted over the circuit, special care must be taken with the office wiring. This is to avoid exces
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
