80 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1956 



28 



24 



IT) 



aJ2o 



03 



O 



16 



to 



If) 



g 12 

 a. 



UJ 



5 8 



3950 3960 3970 3980 3990 4000 4010 4020 4030 4040 

 FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 12 — Characteristics of the band-pass microwave filter. 



m % 



I 



JYYYYYYTin 



Fig. 13. — The regeneration of pulses in the presence of broad-hand, random 

 noise added at each repeater. A — Ini)ut to regenerator, 23rd and 24th trijis, 

 broad-band noise added. B — Ini)ut to regenerator, 23rd and 24th trips, no added 

 noise. C — 20-mc timing wave. 



\ 



