Furuno FA-30 - Manual (Page 11)

3
1.3 Whip Antenna
Location
The location of the AIS VHF-antenna should be carefully considered. Digital commu-
nication is more sensitive than analog/voice communication to interference created by
reflections in obstructions like masts and booms. It may be necessary to relocate the
VHF radiotelephone antenna to minimize interference effects. To minimize interfer-
ence 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 hori-
zon 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 radio-
telephone 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 dis-
tance 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 maximum length is 50 m eters.
• 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