442 



BELL SYSTEM TECHNICAL JOURNAL 



:3h 



UJI- 



o5 



Q-i 



" o 



d 18 



<rt 



CD 



60 



64 68 



76 80 84 88 92 96 100 

 FREQUENCY IN KILOCYCLES PER SECOND 



104 108 112 



(A) 



140 



150 160 170 

 Eb IN VOLTS 

 (B) 



-35 -30 -25 -20 -15 -10 -5 5 10 



4-KILOCYCLE INPUT IN DECIBELS ABOVE I MILLI-WATT 



(C) 



Fig. 4 — Performance curves of channel harmonic generator. {A) Harmonic 

 outputs; {B) Variation of 16th and 26th harmonics with ampUfier plate potential; 

 (C) Variation of 26th harmonic with fundamental input. 



Fig. 5 — Construction of experimental non-linear coils used for harmonic generation, 

 showing core forms, magnetic tape, wound coils, and assembled units. 



