User’s Manual
Page 99 of 117
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additional VHF antenna or you have to connect an external antenna
splitter e.g. the easySPLIT OCB (item no. A027) between the existing VHF
antenna and the easyTRX2 device.
21.2
GPS Antenna
The connection to easyTRX2 devices requires a 5V DC feed for GPS
antennas.
The used GPS antenna must be of the active type (i.e. it should
incorporate a 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 reason for this
is that a proper and flawless GPS signal is required for a correct function
of the easyTRX2 Transceiver product line. (Issue time-slot method, see
„What is AISWhat is AIS??? – „)
The GPS antenna to be used for the easyTRX2 Transceiver must be a
dedicated antenna, i.e. not shared with any other GPS receiver.
If you are equipped with a GPS antenna, e.g. for your plotter, there might
be the possibility to use both devices with this antenna. At first connect
the GPS antenna to the easyTRX2 device. When your plotter is able to
receive and process GPS data from an external source you may establish
the connection to your plotter with the green and white cable (pos. 7+8).
If you chart plotter is not suitable you need both devices and a GPS
antenna respectively.
Rules of thumb for mounting of the GPS Antenna
The GPS antenna should be mounted in an elevated position and
free of shadow effect from the ship’s superstructure (i.e. in free
view to the receiving satellite signals)
