AIS antenna

[Alan H]

What antenna are folks using with their AIS units?


Has anybody used the quarter-wave antenna sold by miltech? I like the price and the fact that you don' t have to install another full-sized antenna.

VHF portable antenna

I'm not inclined to use their antenna splitter. It's $120 (on sale) and I can put a second small VHF antenna on the stern rail and run 18 feet of coax for a lot less than that. Also, that way I'd have a backup VHF antenna in case the masthead antenna fails.

[AnchorageGuy]

We have a Metz standard VHF antenna, and although it is mounted on the mizzen we pick up targets 20 miles away.

[Sandero]

I got a NASA AIS as a birthday present a few years ago and had to work out how to get it to work with the different baud rates with the C80 and then deal with the antenna issue. I prefer the concept of designated functions which makes for more redundancy. So I tool my spare metz antenna and mounted it on a6' x 1" Ø ss pole which is attached at the pushpit. It's about 12' above the water. I've receive signal over land up to 8-10 miles, but I am in pretty shelter waters and AIS is just getting going so I expect to pick up more targets over time. Now I have a second VHF antenna all mounted and ready to use if the masthead one fails. That's better than it sitting in my spares locker, ain't it?

[donradcliffe]

I tried the little rubber ducky antenna from Miltech, but decided the range was only a mile or two, so went with the same system as defjef--mounted a spare VHF antenna on the pushpit. It typically picks up ships about 8-10 miles out, but the masthead antenna has given me targets at up to 60 miles. I understand that some of the new VHF radios come with AIS functionality, so you don't have to worry about splitters or extra antennas.

[Nauticatarcher]

we use normal masthead antenna mounted above our radar on pole at stern, pick up targets 20-30 miles out, and have backup vhf antenna if we dropped our rig

[CSY Man]

Regular VHF antenna on the stern-rail, have seen targets up to 26 NM away...Would not change a thing.

[speciald@ocens.]

I use my mast head antenna with a black box splitter that shuts off the connection to the AIS reciver when I key the VHF transmitter. Getbetter than 20 mile range on the AIS reciever.

[Alan H]

OK, I think that nixes the little "on the unit" antenna. I'll put one on the stern rail, or something.

[Paul Elliott]

Originally Posted by Alan H

OK, I think that nixes the little "on the unit" antenna. I'll put one on the stern rail, or something.

Here's another vote for the stern rail antenna. I originally tried using my "emergency VHF antenna" (the suction-cup-mounted short whip) for the AIS receiver, but the range was pretty poor -- I had it in the cabin roof. I eventually installed a standard short VHF antenna on the stern rail, and the performance is quite improved. I typically receive ships 25-50 miles off now.

By the way, from my house I have received AIS signals from over 2000 miles away, due to tropo-scatter propagation. I would consider this range "excessive" for the AIS system on my boat, though.

[speciald@ocens.]

Go to Sea-Tech web ssite for source of VHF antenna splitter.

[Gene :^)]

Is anyone using the Milltech Marine SR162G AIS receiver? This is a dual receiver with built in GPS receiver that puts out NMEA.

Or is there a better unit out there?

Is the GPS receiver pretty good on this unit?

What GPS antenna are you using with this unit?

Edit: I would like to drive my Nav software with this unit.

Thanks for any info!!

[sandy daugherty]

I used a cheap Shakespeare 8' fiberglass antenna at home, about 70' above bay level and received data from vessels 20 miles away. It will mount on my pushpit. I suspect that those of you receiving positions from vessels 60 miles away are within range of a repeater station, common in the Med. I've not had much luck finding information on repeater sites on the web. Paul Elliott's experience above is remarkable! What kind of receiver and antenna were you using?

[donradcliffe]

I was playing around with the AIS south of Bermuda a couple of days ago, shifting to and from the masthead and the stern rail antenna. One of the contacts with the masthead antenna was 78 miles away, with a predicted CPA of 4 miles, and a TCPA of 6 hours. Sure enough, 6 hours later, the ship passed 3.9 miles astern! Most of the time I use the rail antenna, which gives ranges from 10 to 20 miles.