A SINGLE SIDEBAND MUSA RECEIVING SYSTEM 



333 



mark in a definite lateral position to indicate the magnitude of the 

 delay. The drums have segmental ridges on their periphery which 

 are displaced in various lateral positions. Cam operated hammers 

 descend on the typewriter ribbon above the drums and paper once 

 each second leaving a mark in a lateral position corresponding to the 



ANGLE OF ARRIVAL ABOVE HORIZONTAL 



21 23 5 10 



I 1 1 I il Inn lull 



15 



20 



I I I 



;.(«■- 



h^i. 



il.ii. 



I 



;»i'. 







iiiiiiiiiiiiiiiiiiiiiii|iiii|iiimiii|inii|iii|iiiii 



I J 



D 4 810 4 8 



jJLS STEPS 

 DELAY BRANCH B 



5 10 15 20 25 30 35 40 

 PHASE-SHIFTER POSITION 



4 8 !04_8^ 

 280 31 

 /J.S STEPS 



DELAY BRANCH C 



Fig. 9 — Sample of musa recorder chart. Station GAW. Freq. 18,200 Kc. 



segmental ridge which is beneath and consequently to the delay 

 setting. Two reference lines are used to facilitate the reading of the 

 delay values. 



Operation and Performance 

 The musa system can be expected to give an improvement in 

 signal-to-noise ratio and in selective fading over a receiver using only 



