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BELL SYSTEM TECHNICAL JOURNAL 



order to combat this variable condition, it appears desirable to select 

 an antenna arrangement which does not have sharp directional proper- 

 ties in a vertical plane passed through the horizontal direction of arrival. 

 The type of antenna selected for Netcong meets this requirement by 

 having only a single horizontal row of quarter-wave vertical elements in 

 one plane. Another solution, of course, would be to provide several 

 antennas of different characteristics and to shift about from one 

 antenna to another as the conditions warranted. 



Fig. 9 is a general view of one of the Netcong receiving antennas. 

 Like the transmitting antennas, the conductors are arranged in two 

 parallel planes one quarter wave-length apart in order to obtain a 

 unidirectional system. The conductor in each plane is bent and ter- 



Fig. 9 — One of receiving antennas at Netcong. (24.7 meter wave-length.) 



minated as indicated in Fig. 10 but is much longer than that shown. 

 The vertical members are marked A. As in the transmitting case the 

 directional effect depends upon the manner in which standing waves 

 occur along the conductor. A signal wave arriving broadside to the 

 array, induces voltages in the vertical members which are identical in 

 phase and amplitude. 



Because the vertical members are interconnected alternately at the 

 top and bottom by members of one quarter wave-length and the last 

 horizontal members are one eighth wave-length, the net effect of the 

 induced voltages is the establishment of standing current and voltage 

 waves along the conductor. The receiver is connected at a voltage 

 anti-node and the current which flows through it is proportional to 

 the sum of the voltages induced in the vertical members. In the case of 



