616 



BELL SYSTEM TECHNICAL JOURNAL 



while those in Fig. 23 depend upon a corresponding identity. The identity 

 (27) expresses the fact that the general ''jS-network" can be considered as 

 arising from the parallel connections of the two networks in Fig. 24. 



M^zz 



V, 



y22 



D 



(a) 



(b) 



Fig. 22 (a, b) — Elementary constituents of Fig. 19a. 

 < . y2i_ 



22 



y22 yii y22 



uii yzz 



(a) (b) 



Fig. 23 (a, b) — Elementary constituents of Fig. 19b. 



1^= 



(>9|2+/32t)V,| 



■/3i2 



V2 



V, 



(a) 

 Fig. 24 (a, b) — Elementary constituents of Fig. 8. 



(b) 



V2 



There is at present a tendency towards grid designs of very fine mesh. 

 Such a grid design results in a very large value of the amplification factor 

 and, for many purposes, sufficient accuracy may be obtained by disregarding 



terms containing - as a factor. Under these conditions the network for 



M 

 grounded cathode operation reduces to an L-network, that for grounded 

 grid operation to a unilateral network transmitting in the direction from grid 

 to plate only, while the cathode follower network remains essentially un- 

 changed. 



