790 



THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1953 



-28 



o -32 



-36 



-40 



-60 



0.3 0.4 0.6 0.8 1.0 2 3 4 5 



FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 6 — L3 amplifier modulation coefficients. 



occurrence and then relating them to the requirements previously dis- 

 cussed. Approximately 400 different products or groups of products were 

 studied in the design of the L3 system. All but about thirty of these were 

 found to be of negligible importance for the signal levels and frequency 

 allocations being given serious consideration. On final analysis six of 

 these thirty products were found to be controlling in establishing system 

 levels. Fig. 8 shows the generating signals and the products they form for 

 the six most critical products. The exact way in which the critical pro- 



40 



-i 



Ui 



fi 30 

 u 



Z 



0.2 0.3 0.4 o.e o.e i.o 234 



FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 7 — ij3 repeater gain characteristic. 



5 6 



