A MULTIPLE UNIT STEERABLE ANTENNA 



399 



TABLE IV 



Two Branches 



GCW 9790 kilocycles 



The apparent line loss is 2.6 db. The calculated loss is 3.1 db. 

 The equivalent improvement is 6.1 db to which may be added 0.9 db for the 

 effect of delay, giving 7.0 db. 



The data in the tables are classified roughly according to whether 

 two bundles or one bundle of waves was present. In the latter case 

 the two branches were steered, one on each side of the bundle, a few 

 degrees apart. During these tests slight adjustments in steering were 

 made when indicated by the angle monitoring tube, as in normal 

 operation of the system. The large amount of data taken with GBW 

 makes the results in Table III particularly reliable. This is reflected 

 in the close agreement between measured and calculated line loss. 

 Before discussing the results further the effect of delay needs to be 

 analyzed. 



Correction Due to Delay 

 The effect upon the noise, of delaying one audio output, is shown in 

 Fig. 37. The curves were obtained with the circuit shown in Fig. 35 



o z 



z - 



10 100 1000 



DELAY IN MICROSECONDS 



Fig. 37 — The effect of delay and phasing upon noise output of the MUSA receiver. 



using thermal noise. The equiphase, equiamplitude signal source men- 

 tioned previously was used to supply the inputs. Branch A was kept 

 phased so that the six signals added, and branch B was varied. The 



