74 BELL SYSTEM TECHNICAL JOURNAL 



This equation may be written in condensed form with the aid of (30) 



where 



Fp = Jx{r + ix) - F,(m + iv), 

 r = -^asin^ + 2cos^-2), 

 x= -^{^ + W - 2sin^ + ^cos^), 



(32) 



M = -z^ (^ sin ^ + cos ^ - 1), 



2^40 



e 



2jUo 



J' = — ^ (?cos ^ — sin ^). 



{?>?>) 



Fig. 5 — Real and imaginary components of complex amplification factor 

 of negative grid triodes versus transit angle. 



The significance of (32) is at once apparent when it is compared 

 with the classical form of the equation representing the alternating- 

 current plate voltage, namely, 



F„ 



/„;- 



?>'0 



y.Vo. 



The plate resistance ro has now become complex as likewise has the 

 amplification factor ix. Values of the plate impedance 



Zp = r + ix 



