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BELL SYSTEM TECHNICAL JOURNAL 



By going over the electrical system of the plane, tightening old bonds 

 and loose metal pieces, and adding new bonds and shielding, the noise 

 was reduced to such an extent that the results shown in Fig. 8 for the 

 flight of November 1 were obtained, where Montauk Point was almost 

 reached. Both of these curves fit theory well in the optical range; 



10 20 30 40 50 60 70 80 90 100 110 120 130 



MILES FROM TRANSMITTER 



Fig. 6 — Flight toward transmitter. Wave-length — 4.6 meters; Altitude— 2500 feet; 

 November 16, 1933; 12:10 p.m. to 1:05 p.m. 



beyond this the second curve lies 10 decibels below the first one. 

 Evidently the plane noise troubles were due simply to the lower signal 

 level which had to be received. This level fell lower as the cold 

 weather came on, and additional work on the plane electrical system 

 had to be done. The 4.6 meter receiving set was also overhauled and 

 realigned. Finally, on November 20, we obtained the bottom curve 

 of Fig. 8, which appeared to be the best we could hope for, and the 



