NOMOGRAPHIC SOLUTIONS FOR THE STANDARD CASE 59 
DB 
80 ¥ 
; | 
i 6 4 
bs 
2 
08 aes 
70 yess ae 
: me ees 
300 Loe 
250 a 
65 200 _--- 
ot =150 8 20 
Sean 125 
ekeat ‘i 100 
Sens 75 
ea ee 
ee 50 f 
= 26 
55 20 
is 
10 
50 
Ss 
46 
1 
% EXAMPLE SHOWN 8Y DASHED LINE ; 
b=0 
a=,3 
35 DB=57 
S= 150 
S IN THOUSANDS OF YARDS 
30 
2s 
20 
Ficurs 4 
we may take C’ ~ C. If greater accuracy is desired, 
we may compute C’ directly by the equation 
C= (3.281)? (914) (150) k ties ali 
ie Fe hi B*}~ 
It is interesting to note that equation (8), apart 
from the correction factor (1 — 1/B?), which merely 
serves to improve the accuracy of the result, is 
familiar to many in the construction of so-called 
“fade charts.’’? These diagrams depict merely the 
lobe minima (and sometimes also the maxima). If 
we set b = 0 we get the former, and if we take 
b = 1% we determine the latter. 
The total number of lobes NV is approximately 
N _ 2h hi fe 
Cleat) mene =e 
x — CSO GB) 208 1a tae 
for h; in feet. These will be distributed over an angle 
of 90 degrees. Hence A, the average angle per lobe, is 
gq = 20° _ 4°43 x 108 
oo N Fie hi 
