28 



BELL SYSTEM TECHNICAL JOURNAL 



POSITION 2-.,^^ I 



FOR TARGET A 



TTTT 



POSITION I 



ANTENNA ARRAY 

 PRESE NTATION 



Fig. 25 — Principle of lobe switching 



FOR TARGET B 



SECTION "A" -"A" 



(A) - § MATCHING SECTION 



TRANSMISSION LINE 

 TO MAIN UNIT 



Fig. 26 — Mark 2 & 3 — Antenna schematic 



frequency adjustments, in order to simplify operation and maintenance. 

 The manner in which these objectives were met is described below. 



To obtain lobe switching of the antenna beam, use was made of the fact 



