BROAD-BAM) M ICKDW AV E XOlSE SOL'RCE 



615 



and the observed temperature, to a common temperature of 34° C. Assum- 

 ing that the noise figure of the microwave receiver was constant, source # 1 



1.2 



< .4 



20 40 60 80 100 120 140 



I, MILLIAMPERES. DC 



Fig. 4 — Admittance of the gaseous discharge at 3960 me as a function of the direct 

 current in the discharge. 



16.4 



,.^ 16.2 

 I 



l-|o; 16.0 



§ 15.8 



o 



" 15.6 



15.4 

 30 



50 60 70 80 90 100 110 120 130 

 DISCHARGE CURRENT IN MILLIAMPERES 



Fig. 5 — The microwave noise power is practically independent of the discharge current. 



showed variations whose r.m.s. deviation was ± 0.11 db, while source % 2 

 had similar deviations of ±.092 db. Assuming on the other hand tliat source 

 % 1 held constant and that the microwave measuring set varied with time, 



