AIS Antenna Location

[oliverkinchin]

Good Afternoon.

I was at the boat show recently and brought a AIS engine that communicates to my Standard Horizon Chart Plotter. I know that some threads have already discussed the location of antennas by my questionn is a little more specific.

I brought the AIS Antenna, I do not want to use the VHF antenna. I have a Rival 32 with a gantry on the back the houses the Foruno Radar a wind generator and GPS antenna. On the Pushpit I have a Navtex Antenna.

I would like to mount the AIS antenna on the top of the Gantry as it gives more height, however should I be concerned about interferance from the Radar and the GPS antenna or are they using different frequencies?

I am trying to move away from mounting up the mast and would hope to be able to use the antenna as a emergency VHF antenna should I need, so having access to it is a must.

Also has any one undergone installing one of these with a chart plotter, if so what should I be aware of and is it pretty straight forward?

Your advise, knowledge and recommendations would be much appreciated.

Best wishes,

Oliver (Troskala)

 

[AliM]

In our experience, the AIS antenna was not too sensitive to interference from other antennas, but the Navtex aerial was. Why not rig it up temporarily and test whether it (and everything else) is happy with its location. Then wire it properly, when you are sure it's OK. Plugging it into our SH chartplotter was straightforward, and in St Kats you should get some signals on it pretty quickly if you've done it right!

 

[fireball]

Mounting is pretty straight forward - and I think you're taking the right approach by putting it at the stern.
It won't have interference from the GPS antenna as that is a receive only device - it may get upset by the Radar though - the power radiating out may give some blips every time it sweeps through - I doubt you'd notice though - and if the GPS mushroom is on the same plane as the Radar I'd install to test without hesitation.
However, I can't help but feel a little unsure as to the effect of the radar on the AIS VHF antenna and I would want to install it (the VHF antenna) in a different vertical plane - upside down from the gantry would physically isolate it from any affect of the radar.

 

[Salty John]

What you suggest should present no problems. Most RIBs, for instance, have radar arches that also carry Navtex, GPS and VHF antennas.

Here's some thoughts:
http://saltyjohn.blogspot.com/2010/11/vhf-and-ais-antenna-mounting.html

You can put a PL259 on the AIS vhf antenna cable and then use an SO239/BNC adapter to connect to the AIS engine, instead of the patch cable shown in the sketch. Then you can just switch it to the radio should your masthead vhf antenna be lost for any reason.

 

[Ex-SolentBoy]

Our GPS and VHF aerials are installed under the cockpit coaming of our boat. We can access them from the lazarette lockers. I prefer it this way:-

Shorter wiring runs.
Hidden from view.
Not in the elements.

We still get targets from 20 plus nm away.

 

[Barry Jones]

Don't mount it near the radar - it won't interfere with the GPS if it is a passive AIS receiver.

The height difference between pushpit and arch is minimal in terms of range (especially as you are looking at mainly ships with their AIS antenna around 30m above their waterline).

I would use the pushpit rail.

Good Afternoon.

I was at the boat show recently and brought a AIS engine that communicates to my Standard Horizon Chart Plotter. I know that some threads have already discussed the location of antennas by my questionn is a little more specific.

I brought the AIS Antenna, I do not want to use the VHF antenna. I have a Rival 32 with a gantry on the back the houses the Foruno Radar a wind generator and GPS antenna. On the Pushpit I have a Navtex Antenna.

I would like to mount the AIS antenna on the top of the Gantry as it gives more height, however should I be concerned about interferance from the Radar and the GPS antenna or are they using different frequencies?

I am trying to move away from mounting up the mast and would hope to be able to use the antenna as a emergency VHF antenna should I need, so having access to it is a must.

Also has any one undergone installing one of these with a chart plotter, if so what should I be aware of and is it pretty straight forward?

Your advise, knowledge and recommendations would be much appreciated.

Best wishes,

Oliver (Troskala)

 

[snooks]

I have a pole on the back with a radar on a self leveller, directly above that (also on the self leveller) is the GPS aerial, above that on top of the pole is the RTE and next to that is the AIS aerial.

No problems with the AIS at all. the only interference I get is from radar when it and the RTE are on at the same time but all that means is the RTE "active" light on all the time when the radar is on because of their proximity, but I knew this would happen when I fitted it. Sea~Me said as long as the RTE isn't in front of the beam there won't be any problems

AIS range is in excess of 25 miles

 

[oliverkinchin]

Thank you all for this information. I think I will move the Navtex Antenna from the pushpit as it has ceased working due to water ingress, but I know that is another subject. I will mount the AIS antenna on the pushpit but test out the signal before I finish off the wiring.

I will mount the new Naxtex Antenna internally so as not to have to replace it again.

I will let you all know how I get on.

Thank you,

Oliver

 

[prv]

I will mount the new Naxtex Antenna internally so as not to have to replace it again.

Good idea. Navtex is something akin to Long Wave, so doesn't really care how high up it is.

Pete

 

[nigelmercier]

I have a pole on the back with a radar on a self leveller...

GULP! Radar at head height?

 

[snooks]

GULP! Radar at head height?

Not unless you're over 2 meters tall!

I can stand up underneath the radar and not hit my head on the sticky down bolts

 

[nigelmercier]

Not unless you're over 2 meters tall!
I can stand up underneath the radar and not hit my head on the sticky down bolts

They don't spray their high-power microwaves only in a horizontal plane, personally I'd want to be at least 2m below it.

 

[snooks]

They don't spray their high-power microwaves only in a horizontal plane, personally I'd want to be at least 2m below it.

Just as well you didn't write the installation manual then isn't it? They project 12.5° either side of horizontal and are perfectly safe to mount on a pole.

If our radar was on 24/7, and we were on board 24/7 you may have a point. But it's not, and neither are we.

 

[st599]

They don't spray their high-power microwaves only in a horizontal plane, personally I'd want to be at least 2m below it.

High power at what duty cycle? 0.1%, 0.01% less?

 

[V1701]

Maplin stock an adapter that you can use to connect your aerial to the AIS engine which means you can quickly and easily use it as an emergency VHF aerial if you need to, have enough cable to reach though...