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BELL SYSTEM TECHNICAL JOURNAL 



as could be estimated, during the two-bundle tests in Tables III and IV, 

 The one-decibel correction applied to those results in Table V is there- 

 fore justified. In the one-wave bundle measurements, the percentage 

 of time during which the branch outputs were substantially different 

 was so small that no correction was applied in Table V. In the case 

 of space diversity the correction is also small; about 0.5 decibel seems 

 reasonable. 



O-MEASURED WITH SQUARE LAW DETECTOR 

 •-MEASURED WITH LINEAR DETECTOR 

 501 



10 20 30 40 



Bsa/^SB "^ DECIBELS 



Ssa/^sb in DECIBELS 



NOISE A (nj 



DIVERSITY-* 



NOISE B (^ 



LINEAR 



DETECTORS 



SQ. LAW 



DETECTORS 



TO Es/En 

 MEAS. EQUIP 



Fig. 43 — Test circuit and experimental results of the study of detector characteristics. 



From the point of view of distortion in receiving double side-band 

 signals linear detectors are superior to square-law detectors and this 

 compensates their inferiority in signal-to-noise ratio. The principal 

 reason for using linear detection in the signal-to-noise ratio tests of 

 the MUSA was, however, their experimental advantage in simplicity 

 and accuracy (Fig. 35). 



Random Addition of Static 

 In analyzing the spaced antenna systems at the beginning of this 

 section it was assumed that the static outputs of the antennas add on 

 a power basis. An experimental study of this was made by measuring 



