28 



THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1951 



System Regulation 



The regulating characteristics of the LH and HL repeaters are shown in 

 Fig. 13, (a) and (b). The channel unit regulating characteristic is shown in 

 Fig. 14. The solid curves in Fig. 13, (a) and (b), show change in repeater 



■10 -8-6-4-2 2 4 6 8 



INPUT DEVIATION FROM NOMINAL IN DECIBELS 



1.5 2 3 4 5 6 8 10 15 20 30 40 60 80 100 



TIME IN MINUTES 



Fig. 15 — Stabilization time of repeater or group unit regulator. 



output when the total carrier input power is subjected to flat gain line 

 changes as shown by the abscissa. The dotted curves show the regulation of 

 a long string of repeaters, each regulating for the same line change, as well 

 as for the residual output change passed on into successive line sections. The 

 circled numbers indicate the number of the repeater at which the output 

 will depart no further at the indicated input regardless of how many follow- 



