154 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1957 



ISO 



140 



ai 



LU 



100 5 

 lij 



Q 



60 aj 



z 

 < 



20 



LU 



< 



I 



a 



0.01 0.02 0.04 0.1 0.2 0.4 0.6 1 2 4 6 8 10 



FREQUENCY IN KILOCYCLES PER SECOND 



20 



-20 



-60 



40 



Fig. 7 — DC amplifier gain and phase, production model. 



229 



228 



227 

 Q 



d 226 



5 225 



LU 



a. 

 en 



u 



2 24 



UJ 



_i 



ID 

 < 



223 



222 



221 



100 



200 300 400 500 600 700 800 



SERIES TUBE PLATE POTENTIAL IN VOLTS 



900 



1000 



Fig. 8 — Load regulation. 



