476 



BELL SYSTEAf TECBNICAL JOURNAL 



apparently an optimum loading. Best output is not obtained when the 

 external load matches the generator impedai.ce as in the case of anamplifier. 



6.0 



5.5 



Z 5.0 

 O 

 a. 

 ff4.5 



Z 

 ^4.0 



o 



2 

 UJ 



G 3.5 



IL 

 U. 

 UJ 



2.0 

 1.5 

 1.0 



0.5 



123456789 10 



EFFECTIVE DRIFT, FN, IN CYCLES PER SECOND 



Fig. 8. — Efficiency in per cent vs the effective cycles drift for various values of a para- 

 meter A" which is proportional to resonator loss. These curves indicate how the power 

 output differs for various repeller modes for a given loss. Optimum power operating 

 points will be represented l)y points along one of these curves. For a very low loss resona- 

 tor, the power is highest for short drift times and decreases rapidly for higher repeller 

 modes. Where there is more loss, the power varies less rapidly from mode to mode. 



We return to equation (3.7) for // and assume that we are given various 



n 



values of — . With these values as parameters we ask what variation in 



efficiency may be expected as we vary the ratio of the load conductance, 



C C 



Gl, to the small signal admittance, y«. When 1 = 1 oscillation 



ye ye 



