IMPEDANCE PROPERTIES OF ELECTRON STREAMS 



481 



Kipp occurred. Again the capacitance behaves essentially the same 

 except that it suddenly jumps from a large negative value to the 

 positive value corresponding to virtual cathode operation. 



In comparing the theoretical and experimental results, it is seen 

 that the theory gives predictions which are broadly in accord with 

 experiments. 



-35 



10 



Fig. U- 



VOLTAGE ON FIRST GRID 



-Measured input capacitance of experimental vacuum tube no. 59 

 (grid signal = 0.05 volts r.m.s. at 50 kc). 



Acknowledgment 



I am indebted to Mr. E. J,. Buckley for assistance in the experi- 

 mental work, to Miss M. Packer for the numerical calculations, to 

 Mr. C. A. Bieling for the mechanical tube design, and last but not 

 least to Dr. F. B. Llewellyn for stimulating discussions. 



