AIS set up

[louiseevans]

We have a Comar AIS multi receiver/splitter unit; They recommend wiring it up to the VHF radio, but we're going to use it in conjunction with the chart plotter (Raymarine C Series), not the computer and not necessarily have the VHF on. Does the antennae need a power source from the VHF to make it work? Or can we wire the AIS directly to the chart plotter, use its power rather than the VHF as a power source?
2) Is there a dedicated Raymarine jack plug and lead that i have to use, can't find one in Budget Marine catalogue? (Curacao)

[St. Elsewhere]

Originally Posted by louiseevans

We have a Comar AIS multi receiver/splitter unit; They recommend wiring it up to the VHF radio, but we're going to use it in conjunction with the chart plotter (Raymarine C Series), not the computer and not necessarily have the VHF on. Does the antennae need a power source from the VHF to make it work? Or can we wire the AIS directly to the chart plotter, use its power rather than the VHF as a power source?
2) Is there a dedicated Raymarine jack plug and lead that i have to use, can't find one in Budget Marine catalogue? (Curacao)

Your AIS needs to be connected to a VHF antenna. The power connection should be to its own breaker independent of other equipment, if possible. The Comar box should not require any signal from the VHF transceiver to make it work. I have a Comar Class B AIS tranceiver, but it has its own VHF antenna, so I have not used a splitter. The connection to the plotter just involves the data signals, not power. Your Raymarine manual should define its interfacing capabilities including a connector type, and what signals it is capable of receiving. You will likely need to obtain connector and wire to it.

[David M]

Originally Posted by louiseevans

We have a Comar AIS multi receiver/splitter unit; They recommend wiring it up to the VHF radio, but we're going to use it in conjunction with the chart plotter (Raymarine C Series), not the computer and not necessarily have the VHF on. Does the antennae need a power source from the VHF to make it work? Or can we wire the AIS directly to the chart plotter, use its power rather than the VHF as a power source?
2) Is there a dedicated Raymarine jack plug and lead that i have to use, can't find one in Budget Marine catalogue? (Curacao)

It depends on the antennas design. Some antennas are just an antenna with a coax that leads directly to the GPS unit for satellite signal processing. Other GPS antennas process the satellite signals at the antenna and output a NMEA sentence which can be sent to whichever device will accept a NMEA sentence. The latter type of antenna needs to be powered by 12 volts DC. The former is unpowered.

Your VHF radio does not require an AIS or NMEA connection to function as two-way radio. It does require a NMEA position sentence for the DSC function to work. If it is also an AIS type of VHF radio that displays basic AIS information, then obviously it needs an AIS signal for that function to work...unless it has its own built in AIS signal processing, which it probably does. You can always have your VHF on with the sound down so you do not have to hear the noise, then you can still use the AIS out of the VHF.

You can split an AIS or NMEA signal between two or more receiving devices since the signal travels only one way.

Use the boats 12 VDC as the power source for your AIS receiver so you are not reliant on the VHF being turned on in order for your AIS receiver to function. You want to avoid daisy chaining power sources in case one fails it does not cause another to not function. I run some of my nav equipment to a common bus bar, which is fused. Each nav instrument still has its own inline fuse.

[Paul Elliott]

The Comar AIS Multi receiver does not have a GPS receiver, so no GPS antenna power is needed. AIS Class-B transponders do include the GPS receiver and at least some of these have a preamplified GPS antenna which gets it's power from the transponder via the GPS antenna coaxial cable.

Your VHF does not have to be turned on for the AIS receiver/splitter to operate, the built-in splitter is getting it's power from the AIS receiver. As has been suggested, the AIS receiver should be powered from your house batteries (through a breaker or fuse). You will have to look at the Raymarine chartplotter specifications, but there should be an NMEA input you can connect the output of the AIS receiver to. Sometimes there aren't enough available inputs, and then you need to look at getting an NMEA multiplexer.