Comar Systems LTD AIS-MULTI Receiver/Splitter



This is an AIS receiver with an integral antenna splitter. Not to be confused with separate AIS receiver only or splitter only devices.

The AIS-MULTI is designed to enable AIS reception, with the
minimum of installation by sharing your existing VHF antenna
with the AIS receiver. The unit comprises of a Dual Channel
Parallel Receiver, Antenna Splitter and Interfaces for NMEA In
and Out together with USB, in one enclosure.
The AIS-MULTI Receiver is not waterproof and should be
located in a dry location. The unit can be secured by the 4
mounting holes in the end flanges. Ideally it should be located
within 1m of your VHF radio, otherwise you will need to
extend the cable fitted to the AIS-MULTI.
Antenna Connection:
Firstly remove the VHF antenna plug from your VHF Radio and
plug it into the socket marked VHF Radio on the AIS-MULTI.
Take the 1m VHF radio cable from the AIS-MULTI and plug it
into the antenna socket on the VHF Radio.
Power Connection:
Operation is from the boats DC supply of 12-24 Volts.
Connect the 2 core power cable to the boats DC supply,
ideally from the same source as the existing VHF Radio.
RED Positive +
BLACK Negative –
NMEA Connection:
The NMEA 0183 In and Out is connected via the 4 core cable.
The NMEA Output can be connected to a suitable Chart Plotter to display
AIS targets. The output Baud rate is set to 38,400, if you wish to change
this to 4800 baud, disconnect the power, unscrew the two screws to
release the front cover and move the jumper located to the left to the
4800 position.
YELLOW NMEA Output Positive +
GREEN NMEA Output Negative –
An external NMEA GPS may be connected to the NMEA Input, which
will multiplex the data with the AIS VDM NMEA sentences. The unit
will only accept data input at 4800 Baud.
RED NMEA Input Positive +
BLUE NMEA Input Negative –
USB Connection:
The AIS-MULTI will also output NMEA 0183 data via the USB
connector. You will need to install the drivers on the CD supplied
before the unit will operate correctly. The unit is not powered by the
USB port so to operate correctly the DC power must be connected.
On applying power the Green LED will light and the two
Channel Red LEDs will come on continuously for approximately
10 seconds then extinguish.
If you are within range of vessels transmitting AIS data the
two channel Red LEDs will flash intermittently indicating
reception of an AIS message, this data will be sent out on the
NMEA connection to the Chart Plotter, and simultaneously on
the USB connection to a PC.
Your VHF radio will continue to receive as normal together
with the AIS-MULTI. When transmitting on the VHF Radio the
AIS reception will stop and resume automatically when you
stop transmitting. If the AIS-MULTI is not switched on, your
VHF Radio will continue to operate as normal


Dimensions Overall: 120 x 86 x 37
Power: 9-30 VDC
Current: 110mA @ 12VDC
Output: NMEA 0183
Message type: VDM
Baud Rate: 38400 (4800 by internal link)
Receiver: Dual Channel Parallel
Frequency: 161.975 and 162.025MHz
Sensitivity: -112dBm
Insertion loss: <3dB
Connections: Power 2 core 1m cable
NMEA 4 core 1m cable
USB Socket Type B
Antenna: SO239 Socket 50 Ohm
VHF Radio: PL259 Plug 1m cable