54 



BELL SYSTEM TECHNICAL JOURNAL 



i 6 



a 3 



80 



100 120 140 

 PLATE VOLTS, Ed 



160 



180 200 220 240 



Fig- 2 — Characteristics of a screen-grid tetrode. The curves show tlie plate cur- 

 rent, /p, screen current, /„, total space current. It = Ip + /„ and plate resistance, Rp, 

 as functions of the plate voltage. Control-grid voltage, Eg, is indicated on t he curves. 

 Screen voltage, £,, is maintained constant at 75 \-olts throughout. 



