User Manual

Marine Systems
Aviation Recorders
Rev. 06
Mar . 16/11
165M0014-10
Page 3--16
3.1.3. Installing the VHF Antenna
Installation of a VHF antenna is as important to reliable communications as the
transceiver itself. It is recommended that a high quality antenna be purchased from
an established source and that all manufactures instructions be followed with partic-
ular attention to cable routing and connector installation. Some important consider-
ations in antenna installation are:
F In general, antennas should be located as high as practical on the vessel
and separated as much as possible from each other.
F The VHF antenna should be placed in an elevated position with a mini-
mum of 2m clearance from any construction that is made with conductive
material. In addition, it should not be installed close to any large vertical
obstruction, and the VHF antenna should have a 360  line of sight to the
horizon.
F It is preferable that the VHF antenna is installed at least 3m away from
high power energy sources such as radar and other transmitting radio an-
tennas, and out of the transmitting beam.
F Ideally, there should not be more than one antenna on the same level.
The AIS VHF antenna should be mounted directly above or below the
ship’s primary VHF radiotelephone antenna, and with a minimum of 2m
vertical separation. If the VHF antenna is located o n the same level as
other antennas, the distance between them should be at least 10 meters.
To install the VHF antenna, perform the following:
(Refer to Figure 3--9 and Figure 3--10.)
(1) Position the antenna mounting bracket on a rigid and stru cturally sound sur-
face.
(2) Install the antenna on the antenna mount.
NOTE
: Use only high quality RG213/RG214 coaxial cable and
keep cable length as short as possible to reduce signal at-
tenuation.
(3) Run the coaxia l cable from the antenna to the transponder location.
(4) Trim cable to length leaving a few inches slack at the transponder.
(5) Attach the connectors to the end of the coaxial cable.
(6) Connect the cables to the transponder. Soldering the connection is
recommended.