ViaSat 8116 Series, Инструкция по установке и эксплуатации

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GENERAL INFORMATION
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The mount for both the 16- and 18-meter antennas is the same
elevation-over-azimuth pedestal. The elevation travel limits can be
set at any points between 0 and 90 degrees. The azimuth travel
range is a full 360 degrees covered in six overlapping sectors. Size
11 resolvers are supplied for position readout. Both axes are
equipped with 75 ton (667 kN) jack screws drives. As an option,
100 ton (890 kN) jack-screws can be provided to address additional
demands imposed by very high wind conditions on the 18M
antenna. Access to the drives and the reflector is gained from
inside the mount rather than from external ladders. The feed
electronics can be accessed at any elevation angle through the rear
of the hub.
The motorized package features variable-speed ac motors to
provide higher motor speeds for rapid stowing or slewing in
addition to the slow speeds required for satellite tracking. The
drives are equipped with variable-speed ac motors having a low
speed of about 0.010 degrees per second and a high speed slew rate
of about 0.1 degrees per second. The normal operational rate of
each axis is typically 0.01 to 0.015 degrees per second.
CAUTION
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No buildings, walls, fences, or other permanent
fixtures should be planned for installation any
closer than two meters from the antenna and
foundation envelope without consultation with
the factory.
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The 18-meter antenna will operate or drive to stow in winds up to
90 miles per hour (145 km/h) with the standard 75 ton (667 kN)
actuators. It will survive in any position in winds up to 105 miles
per hour (170 km/h). In the stow position (elevation axis at 90
degrees), the antenna will survive winds up to 140 miles per hour
(225 km/h). Under worst-case conditions, when the antenna is at 0
degrees elevation angle, it will take about 30 minutes to stow the
antenna using the variable speed motors. While the elevation axis
is being stowed, the azimuth axis can be turned to a more favorable
direction relative to the wind, if necessary. The azimuth axis never
needs to be stowed during adverse winds once the elevation axis is
at 90 degrees.
Wind Load Options
With the optional 100 ton (890 kN) actuators, the antenna will
operate or drive to stow in winds up to 90 miles per hour (145
km/h) but will survive in any position in winds up to 125 miles per
hour (200 km/h). In the stow position, the antenna will survive
winds up to 165 miles per hour (265 km/h).
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42S183D
SERIES 8116/8118 16-/18-METER EARTH STATION ANTENNA
1-3