80 



BELL SYSTEM TECHNICAL JOURNAL 



space current collected by the positive net. The magnitude of the net 

 current in this region is shown by the family of curves in the lower 

 part of Fig. 19. 



~lJ 40 



=! 30 



J? 



a 40 

 Pa: 



^1 30 

 cr < 

 D _i 

 ^=! 20 



I- 2 



zz 



10 



-130 -120 -110 -100 -90 



-80 -70 -60 -50 -40 

 CONTROL-GRID VOLTAGE, 



-30 -20 



+ 10 +20 



Fig. 19 — Plate current-grid voltage and net current-grid voltage characteristics 

 of a co-planar-grid tube. The net (positive-grid) potential is maintained constant 

 at 65 volts. A dynamic characteristic is shown for a resistance load of 3400 ohms. 



In Fig. 20, curves are shown giving the power output, and second and 

 third harmonics expressed in decibels below the fundamental, as 

 functions of the peak input when a sinusoidal voltage is applied to the 



