AIS - Splitter or Pushpit mount?

[Lucky Duck]

Probably going to install an AIS receiver on the old tub and was wondering whether to go for a splitter on the masthead VHF antenna or fit one in the Pushpit.

I am minded towards the later as a friend seems to get satisfactory results with a similar set up or would I be reducing the unit's effective range for no good reason?

 

[BlueSkyNick]

Probably going to install an AIS receiver on the old tub and was wondering whether to go for a splitter on the masthead VHF antenna or fit one in the Pushpit.

I am minded towards the later as a friend seems to get satisfactory results with a similar set up or would I be reducing the unit's effective range for no good reason?

Five years ago I argued against splitters. On two boats I put an antenna on the pushpit and was never happy with the results (NASA receivers) so put an antenna on one of the spreaders which worked much better.

On the current boat I have gone for a splitter on the basis that the technology is now more reliable, defaults to VHF if it fails, and there are bigger concerns to worry about.

The Comar unit I bought has a USB output which goes straight into a laptop, so no mucking about with a serial interface as in the past.

 

[Ex-SolentBoy]

Don't even bother with the pushpit. Put the aerial inside somewhere. Mine is under the cockpit coaming.

Easier to install
Nothing to waterproof
Short cable run
Range is more than sufficient for navigation and collision avoidance

 

[Martin_J]

A pushpit mounted aerial (with well made connectors) is ample - and could, if you have the correct adapter plug directly into the back of the fixed VHF if your masthead aerial ever failed.

Picture here showing ship deatils received at up to 40 miles with a simple 1m fibreglass Glomex whip aerial attached to the pushpit.
https://skydrive.live.com/embed?cid...D57B857B59D08B86!1806&authkey=AMJ9dXsKycTpUaU

It's a NASA AIS engine III connected to an SH180 plotter.

 

[Cardo]

Ours is on top of a pole on the pushpit. Works great for our transceiver. We see others boats miles away and they appear to see us as ships have altered course well in advance to avoid us.

 

[bbg]

FWIW I installed mine on the transom next to a stanchion to protect it. The cable was routed / cut so that I could interchange the connections at the VHF / AIS. So could use the transom-mounted antenna for the VHF if the mast ever fell down, and could use the antenna at the top of the mast for the AIS if I ever felt I needed more range. In practice I found the transom-mounted version just fine. I sometimes received signals from 12-15 (once even 18 miles) away, even though the transom was only about 45 cm above sea-level. I was told that my transmit range was somewhat less.

 

[Iain C]

My splitter works fine...does my VHF, FM radio and AIS...

 

[ffiill]

Top of the mast might give a greater range but so long as you know whats a few miles away does it matter.Also heel can reduce reception.

 

[sailorman]

mine is on the stern rail, on a good day picked up a ship moored in Dunkerque i was in Harwich.
i am only interested in ships a few miles away,so quite happy with my set-up, the ais is set not to look more than 10 mls,
Bellfield do not recommend a splitter, with my set-up i have an emergency vhf antenna

Top of the mast might give a greater range but so long as you know whats a few miles away does it matter.Also heel can reduce reception.

 

[Plevier]

My splitter works fine...does my VHF, FM radio and AIS...

At a quick glance splitters range from about £20 to £170! Some of them disconnect the other line(s) when one transmits.
What's the one that works for you please?
Is the expensive sort necessary?

 

[sailorman]

i have one if you want it, £15.

At a quick glance splitters range from about £20 to £170! Some of them disconnect the other line(s) when one transmits.
What's the one that works for you please?
Is the expensive sort necessary?

 

[prv]

Third option, if you are also replacing (or need an excuse to replace ) the VHF, is to get a radio which includes an AIS receiver. You then only need the one masthead aerial, no splitters. I have bought a Standard Horizon GX2100 for this reason.

Pete

 

[BlueSkyNick]

A pushpit mounted aerial (with well made connectors) is ample - and could, if you have the correct adapter plug directly into the back of the fixed VHF if your masthead aerial ever failed.

Picture here showing ship deatils received at up to 40 miles with a simple 1m fibreglass Glomex whip aerial attached to the pushpit.
https://skydrive.live.com/embed?cid...D57B857B59D08B86!1806&authkey=AMJ9dXsKycTpUaU

It's a NASA AIS engine III connected to an SH180 plotter.

That is very good, however the range is a function of how high the other guy's antenna is mounted, eg high on the bridge of a ship, and can also be affected by atmospheric conditions. It doesnt always mean that your own system is working exceptionally well.

 

[BlueSkyNick]

Third option, if you are also replacing (or need an excuse to replace ) the VHF, is to get a radio which includes an AIS receiver. You then only need the one masthead aerial, no splitters. I have bought a Standard Horizon GX2100 for this reason.

Pete

That's my next step too..... same kit, when I can find one cheap !

 

[FWB]

Don't even bother with the pushpit. Put the aerial inside somewhere. Mine is under the cockpit coaming.

Easier to install
Nothing to waterproof
Short cable run
Range is more than sufficient for navigation and collision avoidance

+1

 

[dulcibella]

Pushpit mounting works fine for me - I see the big ships at 20M or so most of the time.

 

[Bobc]

I have a Glomex VHF/AIS/FM splitter, which works fine.