VACUUM TUBES FOR RADAR I.F. AMPLIFIERS 



393 



conditions, because of the presence of space charge, than when the tube is 

 cold, as assumed in deriving equation (11). It has been assumed in making 



04 0.06 0.08 O.IO 0.12 0.14 ( 



"a" DISTANCE IN MILLIMETERS 



Fig. 6 — Band merit vs. grid-cathode spacing. 



0.04 0.08 0.12 



16 020 0.24 0.28 0.32 0.36 

 "b' DISTANCE IN MILLIMETERS 



0.40 0.44 0.48 0.52 



Fig. 7 — Band merit vs. grid-screen spacing. 



the calculations that the current density and the triode inu are held constant 

 while "a", "6" and "c" are varied. In the cases of "a" and "7>", this requires 

 that the control grid and/or screen voltage be varied in such a fashion as to 

 hold /o constant. The current density is nearly independent of "c" over a 



