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BELL SYSTEM TECHNICAL JOURNAL 



the Rocky Point station of the Radio Corporation was sufficiently 

 light to enable one of the two antennas to be devoted to these experi- 

 ments. The measurements were started January 1, 1923 and are 

 still in progress. 



At the present time (April) the results for the first three months 

 of the tests are available. These results are not yet sufficiently 

 complete nor do they cover a sufficient number of variables in terms 



Transatlantic Radio Transmission Measurements 



Diurnal Signal & Noise Variation 



Feh25-Apr.9. *923. 



Fig. 10 



of time, wave length, etc., to enable any very definite conclusions to 

 be drawn from them. They do illustrate, however, the usefulness of 

 the methods employed, and even in their incomplete state show some 

 factors of considerable interest. 



The results of the measurements of received signal, strength and 

 received noise are given in Figs. 9 and 10. The data have been divided 

 and plotted in these two sets of curves because the transmission con- 

 ditions across the North Atlantic appeared to suffer a rather rapid 

 change about February 23rd. Fig. 9 therefore covers the winter 

 period from January 1 (when the test started) to February 23; and 

 Fig. 10 covers the next period from February 25 to April 9. 



