Furuno FA-30, Руководство оператора

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3
1.3 Whip Antenna
Location
The location of the AIS VHF-antenna should be carefully considered. Digital communication is
more sensitive than analog/voice communication to interference created by reflections in obstruc-
tions like masts and booms. It may be necessary to relocate the VHF radiotelephone antenna to
minimize interference effects. To minimize interference effects, the following guidelines apply:
• The AIS VHF antenna should be placed in an elevated position that is as free as possible with
a minimum of 0.5 meters in the horizontal direction from constructions made of conductive
materials. The antenna should not be installed close to any large vertical obstruction. The
objective for the AIS VHF antenna is to see the horizon freely through 360 degrees.
• There should not be more than one antenna on the same plane. The AIS VHF antenna should
be mounted directly above or below the ship’s primary VHF radiotelephone antenna, with no
horizontal separation and with a minimum of 2.8 meters vertical separation. If it is located on
the same plane as other antennas, the distance apart should be at least 10 meters.
• Install the VHF whip antenna (option) referring to the outline drawing at the back of this manual.
Separate this antenna from other VHF radiotelephone antennas as shown below to prevent
interference to the FA-30.
Cabling
• Use coaxial cable type 5D-2V or the equivalent.
• The cable should be kept as short as possible to minimize signal attenuation, and the maxi-
mum length is 50 meters.
• All outdoor-installed connectors on coaxial cables should be fitted with preventive isolation
such as vulcanizing tape to protect against water penetration into the antenna cable.
• Coaxial cables should be installed in separate signal cable channels/tubes and at least 10 cm
away from power supply cables. Crossing of cables should be done at right angles (90
degrees). The minimum bend radius of the coaxial cable should be 5 times the cable's outer
diameter.
Horizontal separation distance
More than 10 m
Vertical separation distance
Other VHF
whip antenna
More than 0.5 m
More than
2.8 m
Whip antenna
for AIS