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BELL SYSTEM TECHNICAL JOURNAL 



motor driven" winch to adjust its interior angles, thus providing control 

 of the directivity of the antenna. This antenna could he "steered" so 

 that either the major lobe or the first null could be used to receive or 



90 80 70 



ANGLE IN DEGREES 

 50 40 



y//y// ////// '///////A v/// 



■CALCULATED I t-S^X 



• MEASURED / H=V2 



.^=58° 



Fig. 14 — Receiver current diagram of incident plane directivity with test antenna 

 one-half wave-length above ground. Major lobe only. 



discriminate against the components of the received signal. The angle 

 of arrival of these components was measured by the methods described 



ANGLE IN DEGREES 

 90 80 70 60 50 40 30 



Fig. 15 — Receiver current diagram of incident plane directivity with test antenna 

 one wave-length above ground. Major lobe only. 



by Friis, Feldman and Sharpless.'^ The agreements were at all times 

 close. This work was incidental to some fading studies the results of 

 which also checked qualitatively the directivity calculations. 



