TECHNICAL SURVEY 
e rp wan 
me waa 
» 
FIGurE 5 
Near the horizon, however, the angle per lobe A» is 
somewhat smaller, to wit: 
_ 360° _ 5°64 X 10! 
a aN Fine hi 
When A> < 0°.1, the lower lobes are so closely 
packed that the drawing of a coverage diagram 
becomes almost impossible. For such cases one 
EXAMPLE SHOWN BY DASHED LINES 
NOTE: WHEN &<¢ 273, C IS NEGATIVE 
WHEN ©) 2/3, C IS POSITIVE 
h, IN FEET, fme!N MEGACYCLES 
k=3 
& = 0.48 
h, fm¢ = 100,000 
C=18 
should determine, for a given decibel value, the lower 
edge of the lowest lobe. Then, with the aid of the 
nomograms for b = 1%, calculate merely the posi- 
tions of maxima of the other lobes. 
A work sheet for coverage diagram calculations 
is shown in Table 2. As an illustrative example we 
have selected the case in which 
hi = 100 ft, fine = 3,000 me, db = 46. 
