CALCULATION OF RADIO GAIN 423 
= Vote 5) (sd- hee h,) as unity.) 6 is large for horizontally polarized waves, 
but for vertically polarized waves it may vary con- 
siderably, as may be seen from Figure 53. In Figure 
54, the phase of 5 is given. For wavelengths less 
than 10 meters | 6 |, as given by Figure 53 for vertical 
polarization, is large except in the VHF range over 
sea water, ¢, = 80,0 = 4. 
The ground constants «, and o for water and 
various types of earth are given in Table 10. For 
\ < X, the ground material is a dielectric earth. 
TasBLe 10. Ground constants. 
€ 
Type of ground ee Sie 
Sea water er = 80 o =4mbhos gee meter 0.33 m 
Fresh water «¢ =80 ¢ =5x10° 267 
Moist soil €¢=30 o =0.02 25 
Fertileground «-=15 o=5 X10-3 50 
Rocky ground «=7 o« = 10-3 117 
Dry soil e=4 « =102 6.7 
Very drysoil «¢=4 «a=10°% 66.7 
10 
aaa iii me 
A 
3. The mode numbers 7,. These numbers are given 
below for the two limiting values for 6 = O (infinite 
Fieure 51. F(A) [representing ["2(A)] versus A for use in conduetivity or \—> w),and for § = o, ice., the dielec- 
equation (190). 
tric earth. 
or 
5-1/3 (4)? (194) 
s = 4.43 X 10° (<) 194 ; = 
‘ a wNo 5 =0 ea 
e. 7, are complex numbers which characterize eel eeys 2 ee 
the individual terms (modes) in equation I PRO SMa EDe T1,0 = 1.856 € 
(192). They are a function of 6. 2 |ro9 =2.577 627/83 72.0 = 3.245 e*/3 
f. He ae are height-gain functions Bulla een Ue ete 
2A4l Tin 4, Ifn >4, 
2. The complex ground parameter 5. 6 depends on = = = 
the wavelength and the electrical constants of the Tn,6 =4[B4(n+3)P/3e77/9| Tyco =A[3m(n-+1) |? SeIm/3 
ground. (The dielectric constant is referred to air 
+20 
+10 
tr) 
{90° —+ 1-4 ° 
Steg 
BA 
aS 
Sy 
isl = 10 
ceva aT 
al : 
ass DS —20 
=S5 
ost fl venmea POLARIZATION ie FOR aa 20 aio 
n 4 ie ze 
paler MN ese etl 
: SEAM CTC Bh. 
0,01 0.02 04 100 500 
Ficure 52. M(6) versus | 6 | for use in a (190), vertical polarization. 
