4
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 signicant 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 specication 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
2
(see Table 1), the
above specications 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 specication will be exceeded (0.3 x 1 = 0.3 >0.25).
Less than 0.8 m
Mast Clamp GC-038B (option)
Example of a 50MHz Band, 5-Element Yagi Antenna
Sq. Ft M
2
Sq. Ft M
2
Sq. Ft M
2
Sq. Ft M
2
Sq. Ft M
2
1 0.093 6 0.557 11 1.022 16 1.486 21 1.951
2 0.186 7 0.650 12 1.115 17 1.579 22 2.044
3 0.279 8 0.743 13 1.208 18 1.672 - -
4 0.372 9 0.836 14 1.301 19 1.765 - -
5 0.465 10 0.929 15 1.396 20 1.858 - -
To Next Page
Loading...
Need help?
General
