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BELL SYSTEM TECHNICAL JOURNAL 



combine with that generated in the grid circuit and amplified in the 

 plate circuit. 



Inasmuch as the amplification factor decreases, and the plate 

 impedance increases as the grid potential goes negative, the grid 



1.0 

 .9 



0123456789 10 Z_ 



Ro 



Fig. 1 



potential wave is amplified more efficiently on the positive than on the 

 negative lobe, with the result that the plate current wave is limited on 

 one side by the grid current cut-ofif, and on the other side by plate 

 current cut-off. The second cut-off tends to make the output wave 

 more nearly symmetrical about a horizontal axis; it is therefore 

 equivalent to an increase in the odd order modulation which we do not 

 employ here, and to a reduction of the even order products, one of 

 which — the second order sideband — is used to transmit signal charac- 

 teristics. It follows that for efficient modulation we must do one of 

 two things — phase the grid and plate products to add, or remove one 

 of the conflicting sources of modulation. 



To account for the effect of plate distortion we may apply the same 

 general procedure to the plate circuit as we did to the grid circuit. 

 The plate current-grid potential relation is given as 



/ = hxixv + h-i,\x-v- (11) 



and the solution for the current components may be written down 

 directly since the problem presents itself in the same form as the grid 

 circuit situation previously considered. Hence if we change the a 



