DEVELOPMENTS IN SHORT-WAVE DIRECTIVE ANTENNAS 669 



The Inverted V 

 The combination of two tilted wires to form the inverted V is shown 

 in Fig. 10. The directional characteristics are appreciably improved 



PERFECT GROUND 



SPACE 

 VOLTAGE 



EFFECTIVE 



WIRE 

 VOLTAGE 



CURRENT AT 



R-DIRECT 

 PROPAGATION 



9 8 7 6 



-^ ^ t \ 



^ / \ \ 



^ I ^ 



CURRENT AT 



R VIA "— 



END REFLECTION 



\ 



5 4 3 2 1 



*-y \ \ - 

 ^ ^ t \ _ 



^ I ^ 



\ 



RESULTANTS 

 ® ® 



\ 



>' 



-Ocj) 



Fig. 10— Vector relations in an inverted \' antenna. 



with a consequent increase in signal output; also, the far end of the an- 

 tenna becomes accessible for termination purposes, near the ground. 

 These terminations will be discussed later. The inverted \' requires no 

 more supporting structure than the tilted wire, therefore its additional 

 cost is very small where the land is available. Fig. 10 is a vector pic- 

 ture indicating that the two elements of the inverted V add in proper 

 phase relation. 



In connection with Fig. 9, it has been mentioned that the small in- 

 accuries in tilt angle, due to departures from the design frequencies, 

 can be counteracted by another wire in combination having an opposite 

 trend. The inverted V of Fig. 10, is an example of one such possible 

 arrangement. Since the tilt angle error is opposite in direction for each 

 leg of the V, in combination, their optimum direction of response will 

 remain unaltered. This will be illustrated by calculated directive 

 diagrams which will be given later. 



