58 TECHNICAL SURVEY 
b=0 
EXAMPLE SHOWN BY DASHED LINE 
B= 0.112 
Y= 12.2 
06, = 0-47,05= 0.91 
Figure 3 
For the upper lobes considerable simplification is 
possible. We may omit all the steps involving cal- 
culation of a. We determine the various B’s as before. 
Then, as long as B > 1 we employ the equation 
10°/ 1 \? 
—db/19 — 2 
10 = (sas) x 
E + ( — B) sin? 7 | 
This equation gives S directly for each decibel value 
and assumed value of b. The nomogram for this 
problem appears in Figure 7. We then obtain H from 
equation (2), with aset equal to unity. 
_ (3.281) (914)? 
2r ee 
H 
3.281)? (914) (150 
sec A B 
In equation (3) we have written C’ instead of C. 
For much of the range, wherever B is very large, 
