Sea Tel DTV04, Инструкция по установке и эксплуатации

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Basic System Information DTV04 HD TVRO Antenna
3-2
Blockage
- Blockage is loss due to an object in the path of the signal from the satellite to the dish.
If an object that is large and dense is positioned in the path of the signal from the satellite, it will
prevent sufficient signal from arriving at the dish. The signal can not bend around, or penetrate
through, these objects. The reception will be degraded or completely interrupted until the object is
no longer in the path of the signal to the dish. The dish is actively driven to remain pointed at the
satellite (toward the equator) so, as the boat turns a mast or raised structure on the boat may
become positioned between the satellite and the dish. Blockage may also be caused a person
standing near the radome, tall mountains, buildings, bridges, cranes or other larger ships near your
boat. Signal will be lost when the boat is housed inside an enclosure that the signal cannot
penetrate, like a paint shed or a berth with a roof. Moving or rotating the boat to position the
antenna where it has an unobstructed view to the desired satellite will restore the antennas ability
to receive the satellite signal.
Due to the nature of the reflector/feed design it is possible to have blockage to 1 or
more satellites even while actively tracking 101
º
W.
•
The graphic to the right depicts a
vessel with its’ BOW oriented such
that the two “diesel Stacks” at the
vessels aft are situated so that they
do not cause any physical blockage,
thus allowing full line of site to all 5
DIRECTV satellites.
Figure 3 System tracking with line of site to all 5 satellites*
•
The graphic to the right depicts a
vessel with its’ BOW oriented such
that the two “diesel Stacks” at the
vessels aft are situated so that they
do cause physical blockage thus
allowing line of site to only 2 of the 5
DIRECTV satellites. Satellites 99
ºW
,
101
ºW
, and 103
º
W are blocked by
the two stacks. This is the only
scenario (of the three examples listed
on this page) where a properly
defined blockage zone would trigger a
BLOCKED
status.
•
The graphic to the right depicts a
vessel with its’ BOW oriented such
that the two “diesel Stacks” at the
vessels aft are situated so that they
cause partial physical blockage thus
allowing line of site to only 3 of the 5
DIRECTV satellites. Satellites 110
º
W
and 119
º
W are blocked by the two
stacks.
*For illustration purposes only. The
relative azimuth angle(s) between the antenna and the satellites shown in these graphic are exaggerated
and not drawn to scale. The actual relative azimuth delta between the 5 satellites will vary and is based
on the vessels current geographic location.
Figure 4 System in a blocked condition*
Figure 5 System in a partially blocked condition.*