. The Bell System technical journal . 130B1 SUBSCRIBER SETS TELEPHONEREPEATER ^-r-\ Fig. 13—System laj-out, in voice band. e- t BRANCHLINES SHORT-HAUL fAHRIKU TELEGRAPH 685 in this frequency-modulation system, a sudden loss of 3 db causes littledistortion. The series resistances may serve another purpose besidesprotecting against short circuits. If one branch has a much greater at-tenuation than the others, the resistance values in series with the shorterbranches may be increased so that more energy is directed into the longerbranch. Emergency Circuits If a circuit containing no intermediate b
. The Bell System technical journal . 130B1 SUBSCRIBER SETS TELEPHONEREPEATER ^-r-\ Fig. 13—System laj-out, in voice band. e- t BRANCHLINES SHORT-HAUL fAHRIKU TELEGRAPH 685 in this frequency-modulation system, a sudden loss of 3 db causes littledistortion. The series resistances may serve another purpose besidesprotecting against short circuits. If one branch has a much greater at-tenuation than the others, the resistance values in series with the shorterbranches may be increased so that more energy is directed into the longerbranch. Emergency Circuits If a circuit containing no intermediate branches fails, a regular mes-sage circuit can be patched in to replace it until the trouble is 15 shows trunks to be used for making this patch in the case of two-wire circuits. They contain 3 db pads which reduce the signal level tocompensate for the change from 0 db transmission level on the regularline to +3 db level on the message circuit. The 43A1 system may operate also over a four-wire circuit, whichaccommodates
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
