Blonder tongue AMM-806, Справочное руководство, Страница: 217 / 285

210
Antenna Spacing Chart
Dimensions are in inches
Dimension Notes:
A) The minimum
horizontal
spacing
between
the tower
structure and
the antenna
crossbar.
B) The
recommended
vertical spacing
for a gain
of 3 dB.
B/2) The minimum vertical spacing between the antenna
crossbar and adjacent mechanical structures.
C) The recommended horizontal spacing for a gain of 3 dB.
D) The minimum spacing between antennas of different channels
and is the figure given for the antenna with the lowest frequency
Formulae:
One Wavelength in space . . . . . . . . . . . . . . . .
λ
(inches) = 11811
Freq. in MHz
One Wavelength in 75 Ohm coax (solid)
λ
(inches) = 7783
Freq. in MHz
One Wavelength in 75 Ohm coax (foam). . . .
λ
(inches) = 9565
Freq. in MHz
Antenna Nulling (finding H) . . . . . . . . . . . . . . . . . . d (
λ
) = 1
2 sin
φ
Channel A B C D
No. 2/3
λ
1
λ
1/2
λ
2 113 138 208 104
3 101 125 188 94
4 91 115 172 86
5 78 100 150 75
6 72 93 139 70
FM 72 80 120 60
7 40 44 67 33
8 39 43 65 32
9 37 42 62 31
10 36 40 61 30
11 35 39 59 29
12 34 38 57 29
13 34 37 55 28