Aerial Fitting on A-Frame

FlyingYammy · 19 March 2007, 20:48

Just fitting some electronics to the new RIB - Garmin 2110 plotter, Icom DSC radio and NASA AIS engine. The problem I have is where to put the aerials on the A-frame. The NASA AIS says it's receiving aerial must be a meter away from any transmitting aerial, and the Garmin GPS aerial has to be the same distance away. There are only 2 positions on the A-frame where I can fix them - I was hoping to fit both VHF aerials (for DSC radio and AIS) about 8 inches apart near the centre, with the GPS aerial on the fixing at one end of the frame. This puts the GPS aerial about 2 feet from the transmitting VHF aerial, but the AIS aerial is obviously much closer than the meter it asks for in the instructions. Does this just mean that the AIS will not receie any data whilst I'm transmitting on the radio, or will it damage it? I can't be the only person who is trying to fit the same amount of equipment on an A-frame with not much space. Any advice gratefully received!

BogMonster · 19 March 2007, 20:51

Put a big Escort Cosworth style wing on the A frame

Sorry I have no idea - but I am curious as to what an AIS is?

rickuk3 · 19 March 2007, 21:16

Think I read some where that you can mount the AIS aerial on the deck it does not need to be mounted on the A frame.

MikeCC · 19 March 2007, 21:17

I think you'll need to put one of the antennae on the console somewhere.

I'd put the GPS and VHF either end of the A-frane and AIS on the console. You can use one of the short VTronix Heliflex or Rib Raider type.
See here for details

Although height is always better, AIS or GPS should be OK on the console. You want your prime position for the VHF radio antenna for best possible voice transmiit/receive.

With GPS or AIS, if you lose the odd signal, it's not the end of the world as they will be refrreshed on a frequent basis. If your mayday message is lost, you may not get a second chance!

Because AIS is basically a data transmission, any corruption in the signal will just result in useless information.

Stephen - AIS is 'Automatic Identification System' Has to be installed on all vessels over 300 tonnes and all commercial passenger vessels. It transmits at high end of marine VHF frequencies and giives the ships name, MMSI number, position, speed, course and heading every few seconds. The data it sends is another NMEA sentence set (like GPS). Using something like the NASA AIS Engine, you can decode the data and display it on chartplotters. Not all chartplotters support AIS input though.

Perhaps in the fullness of time we'll see it as an integrated feature on chartplotters with antenna input directly into the unit.

FlyingYammy · 19 March 2007, 22:06

Cheers for that Mike. You may also be able to answer the question I just asked on another thread, about which DSC radios are currently able to send NMEA DSC data to the plotter. I want AIS and DSC data to be shown on my Garmin 2110 as it has 2 NMEA input ports.

Cookee · 20 March 2007, 09:57

Quote:

Originally Posted by FlyingYammy

Cheers for that Mike. You may also be able to answer the question I just asked on another thread, about which DSC radios are currently able to send NMEA DSC data to the plotter. I want AIS and DSC data to be shown on my Garmin 2110 as it has 2 NMEA input ports.

I think the Standard Horizon kit does this - Jon Brooks will confirm - got a VHF and GPS on the way from them and it all talks to each other!

MikeCC · 20 March 2007, 14:44

Quote:

Originally Posted by FlyingYammy

Cheers for that Mike. You may also be able to answer the question I just asked on another thread, about which DSC radios are currently able to send NMEA DSC data to the plotter. I want AIS and DSC data to be shown on my Garmin 2110 as it has 2 NMEA input ports.

The Standard Horizon GX1500 is a good deal for the price.

ICOM M505 and M603 models also provide DSC NMEA out.

As far as I'm aware, the Navman 7200 doesn't - it has the cables but not the capability (stand to be corrected on that one).

Mike