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Rotator Unit Components and Dimensions
The size and type of antenna(s) that can be attached to this rotator will differ widely, de-
pending on the installation method, local terrain, and the maximum expected wind speeds
at your location. The following pages describe typical antennas which are acceptable for
installation with the G-450ADC/-450CDC. The discussion below assumes maximum wind
speeds of 30 meters per second (67 mph/108kph), and it is recommended that you include
a safety margin of at least 30 % to account for higher wind gusts or other factors which
might potentially cause damage to your installation.
Pole- Mounted Antennas
Mounting of the rotator on a pole or mast results in a significant de-rating of the size of the
antenna which can be mounted, due to the tremendous bending forces applied to the ro-
tator clamps. For pole mounting, the attached antenna must have a net mounted weight
(combined weight of antenna plus mast) of 10 kg or less, and the product of multiplying the
[Antenna Wind Load Area (in m2)] by the [Height of the Antenna Mast (in m)] must be 0.25
or less (see Figure and Table 1).
[Antenna Weight] + [Mast Weight] < = 10 kg.
[Antenna Wind Load Area] ´ [Height of Antenna Mast] < = 0.25
Refer to the antenna manufacturer's specification sheet for determining the weight and the
surface area of the proposed antenna.
Example: For a 50 MHz 5-element antenna of surface area of 0.3 m
above specifications for pole mounting will be met if (A) the antenna is mounted
on a mast not longer than 0.8 m (0.3 x 0.8 = 0.24 <0.25), and (B) if the mast
weight plus the antenna weight is less than 10 kg. However, if the mast is 1 me-
ter long, the specification will be exceeded (0.3 x 1 = 0.3 >0.25).
Example of a 50MHz Band, 5-Element Yagi Antenna
2
Sq. Ft
M
1
0.093
2
0.186
3
0.279
4
0.372
5
0.465
4
2
Sq. Ft
M
Sq. Ft
6
0.557
11
7
0.650
12
8
0.743
13
9
0.836
14
10
0.929
15
Less than 0.8 m
Mast Clamp GC-038B (option)
2
M
Sq. Ft
1.022
16
1.115
17
1.208
18
1.301
19
1.396
20
2
(see Table 1), the
2
2
M
Sq. Ft
M
1.486
21
1.951
1.579
22
2.044
1.672
-
-
1.765
-
-
1.858
-
-
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