DETECTION OF TWO MODULATED WAVES 

 Case 2 



15 



In this case the programs are identical and consequently the speech 

 from the two stations will undergo simultaneous fluctuations of 

 intensity. We shall here assume that the two stations have the same 

 degree of modulation at any instant. We may then take our data 

 from the curves for which M = m. However, this does not apply to 

 the carrier beat note, since its intensity is independent of the degree of 



Fig. 5 — Curves along which the ratio of the carrier aniplitudes received from two 

 stations has a constant value K, as indicated. Attenuation small. 



modulation of either station and its interfering effect will be determined 

 by conditions which exist when the desired station has a low degree of 

 modulation. Hence the discussion of this component of the inter- 

 ference will be exactly the same as in the preceding case. 



Referring to Figs. 1 and 4, it is evident that by far the greatest 

 portion of the displaced side band interference is due to the g ± w 

 components, in the case of the straight line detector, and the q ± u 

 and p ±^i components in the case of the square law detector. The 



