THEORY OF MULTI-ELECTRODE VACUUM TUBES 81 



control grid. The curves were obtained with the indicated values of 

 load resistance, and with the indicated bias voltages applied to the 

 grids. In each case the grid voltages were adjusted to give a plate 

 current of 35 milliamperes. The curves are very similar in form to 



iue 



•^^45 



_3 



^-X V/ \x //^' 



3 \y/ \\//' 



< m 



I _i 

 • uj 45 

 Q CD 



% P. 



30 40 50 60 



INPUT IN PEAK VOLTS 



Fig. 20 — Co-planar grid tube. 

 Power output, P, in watts, second and third harmonics in db below the funda- 

 mental, as functions of peak input when a sinusoidal voltage is applied to the control 

 grid. 



