Quick Instruction, Version 2.2
Page 29 of 43 pages
Weatherdock AG Sigmundstraße 180 90431 Nürnberg
Tel.:+49 911 37663835 www.weatherdock.de
3.8.3
VHF Antenna
Your regular VHF antenna which you’re using for VHF radio will be
connected to the easyTRX2 (-IS)
3.8.4
GPS Antenna
For the GPS antenna there is a TNC female bulkhead connector used,
that mounts to the back of the case. This port provides the 5V DC feed
for the active GPS antenna required by the easyTRX2 unit.
The GPS antenna used must be of the active type (i.e. it should incorpo-
rate an LNA) and must be suitable for marine shipboard applications
(index of protection, ruggedness, means of mounting, etc.). An antenna
should be selected with a gain (in dB) depending on the length of cable
between the antenna and the AIS unit; after subtraction of cable and
connector losses a minimum total gain of 20 dB should be available at
the easyTRX2 unit GPS antenna connector. The GPS antenna to be used
for AIS use must be a dedicated antenna, i.e. not shared with any other
GPS receiver. Installation of the GPS antenna is critical for the perfor-
mance of the built in GPS receiver which is used for timing of the trans-
mitted time slots and for the supply of navigational information should
the main navigational GPS fail.
We strongly recommend that:
The GPS antenna is mounted in an elevated position and free of
shadow effect from the ship’s superstructure.
The GPS antenna has a free view through 360 degrees with a
vertical angle of 5 to 90 degrees above the horizon.
As the received GPS signal is very sensitive to noise and interference
generated by other onboard transmitters, ensure that the GNSS
antenna is placed as far away as possible from radar, Inmarsat and
Iridium transmitters and ensure the GPS antenna is free from direct
view of the radar and the Inmarsat beam.
It is also important that the MF/HF and other VHF transmitter
antennas are kept as far away as possible from the GNSS antenna. It
is good practice never to install a GNSS antenna within a radius of 2
meters from these antennas.
