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BELL SYSTEM TECHNICAL JOURNAL 



during the course of experimentation to be external noise ^'' some ten 

 decibels higher than thermal noise, as received on a single rhombus. 

 At the end of the test the operator at Rugby keyed the transmitter 

 with tone, advising us that the schedule was completed and wishing us 

 "good night." With one antenna the signal was hopelessly lost in 

 noise; with the six antennas the code was readable. 



TABLE III 



Two Branches 

 GBW 14,440 kilocycles 



The apparent line loss is 3.8 and 3.9 db for the one-wave and two-wave groups, 

 respectively. The calculated loss is 3.8 db. 



The equivalent improvement for one-wave group is 6.8 db to which may be added 

 the later determined correction of 1.2 db for the effect of delay, giving 8.0 db. 



The equivalent improvement for two-wave groups is 5.7 db to which may be added 

 0.8 db for the effect of delay, giving 6.5 db. 



More comprehensive measurements were made on GBW (14,440 

 kilocycles) and a few on GCW (9790 kilocycles), using the two 

 branches. Since an unmodulated carrier was used, rectified carrier 

 being taken to represent signal, there was no criterion for setting the 

 audio delay. Accordingly, it was kept at zero and a correction intro- 

 duced later. The results are shown in Tables III and IV. 



^' This noise, which was directive to the extent that four-decibel variation occurred 

 with steering the MUSA, was doubtless a sample of the "star static." It was 

 encountered also on 31 meters in October. See footnote (32). 



