ACCEPTOR AMPLIFIER— NEGATIVE FEEDBACK METHOD 

 B is the transmission characteristic for a parallel T, which we have seen is 



1 1 



1 



4y 



. where oj^, 



<x> 



Mr^ 



CO 



CR 



Thus 



B 

 Figure 13.9 



Font 



in 



\co„ coj 



out 



in 



(JO 0)^ 



,C0„ CO 



16 



1.1/2 



(A + ly 





16 



This expression is, naturally enough, equal to ^ at co == co^ and smaller 

 elsewhere. To find the Q of the 'resonance' we consider, as before, the points 

 at which the gain has fallen to Al(2y^^. At these points we have 



A /l\i/2 



= A 



(2)1/2 



(1) 



0) CO 



y(0. 



CO J 



+ 16 



(^+l)2(-_^«) +16 



1/2 



whence 2 



CO CO, 



l'^'Jo 



CO 



+ 16 =(.4 + 1) 



2 li^ ^ 



16 



, £0, 



CO 



:. ((^ + 1)2-2) 





16 



201 



