DEVELOPMENTS IN SHORT-WAVE DIRECTIVE ANTENNAS 677 



Figs 15 and 16 likewise give us the null points. These are seen to 

 be 0, 30, and 90 degrees in Fig. 15 and 34, 57, 74, and 90 degrees in Fig. 

 16. 



Fig. 16— Vertical plane design chart. 



Using the above determined dimensions, the complete directive 

 diagrams are calculated to determine whether a satisfactory result has 

 been accomplished. Fig. 17 is the complete vertical plane diagram as 



pig_ l7_Vertical plane directive diagram. 



calculated from the previously given equation. Should some undesir- 

 ably large minor lobe be present, it is often possible to suppress it by 

 slightly changing one of the variables. A knowledge of the location of 

 the null points, as given by Figs. 15 and 16, is a valuable guide in this 

 accomplishment. 



