L3 Technologies AISA1 Manual Do Utilizador

Marine Systems

Aviation Recorders

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:

In general, antennas should be located as high as practical on the vessel

and separated as much as possible from each other.

The VHF antenna should be placed in an elevated position with a mini-

mum of 2 meters clearance from any construction that is made with con-

ductive 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.

It is preferable that the VHF antenna is installed at least 3 meters away

from high power energy sources such as radar and other transmitting ra-

dio antennas, and out of the transmitting beam.

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 prima-

ry VHF radiotelephone antenna, with no separation and with a minimum of

2 meters vertical separation. If the VHF antenna is located on 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 3–6 and Figure 3–7.)

(1) Position the antenna mounting bracket on a rigid and structurally sound sur-

face.

(2) Install the antenna on the antenna mount.

(3) Run the coaxial 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.