AIS aerial recommendation - stubby, pulpit mount

As to the OP intending to use a stubby.. Why?

Or more importantly why not use a standard stainless whip?.. If you are worried about crew poking their eyes out then a short extender at the base could put the tip at 6' from the deck and perhaps a small ball on the end would give added protection.

A stubby really will not provide the same level of either Tx or Rx than a simple whip would provide.
 
Martin_J said:
As to the OP intending to use a stubby.. Why?

Or more importantly why not use a standard stainless whip?.. If you are worried about crew poking their eyes out then a short extender at the base could put the tip at 6' from the deck and perhaps a small ball on the end would give added protection.

A stubby really will not provide the same level of either Tx or Rx than a simple whip would provide.
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The extra range won't be huge from an s/s whip.
Completely agree about mounting whatever on a bit of a post, less damage from crew, also from shorelines etc. Less shadowing by people on deck etc etc.
 
When you're on a sinking boat.. and you have a choice of a stubby on the rail or a whip on a pole.. I know which I'd rather have.
 
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thalassa said:
If you at some point want to exchange your AIS receiver for a tranceiver, then take into account that most splitters will not work when sending AIS sentences.
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I'm fitting a transceiver. I was thinking of an active splitter which, as far as I can tell, works both ways.

Martin_J said:
As to the OP intending to use a stubby.. Why?

Or more importantly why not use a standard stainless whip?
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Because I do not care for the aesthetic of a tuna boat, that's why. I'm still completely undecided, but veering slightly towards the splitter and the masthead whip for added range.
 
JumbleDuck said:
I'm fitting a transceiver. I was thinking of an active splitter which, as far as I can tell, works both ways.



Because I do not care for the aesthetic of a tuna boat, that's why. I'm still completely undecided, but veering slightly towards the splitter and the masthead whip for added range.
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No real benefit of range with a mast head. Sure you will pick up more but the stubbies I have, one on pushpit and the other boat on a short pole both give a reliable 15 mile range. More than enough in practice.
 
JumbleDuck said:
No you don't! I might still go for a splitter, but what the hell.
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I think that a lot of the replies haven't spotted the fact that the HP-33A is a transponder/transceiver and are giving advice suited to a receiver.

I only know of one Glomex splitter and it is not meant to be used with a VHF radio and AIS transponder. I have one on my boat and I seem to remember the documentation specifically mentioning "not for use with AIS transponder". I'll see if I can find the documentation.

I don't use the Glomex splitter now as I purchased an AIS transponder.

EDIT: I think that my original documentation is on the boat. However, I found one advert with text "Not compatible with AIS transponders."
http://www.force4.co.uk/glomex-vhf-ais-am-fm-radio-splitter.html
 
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RichardS said:
I thought that we were only ever talking about active splitters? These are designed to work with AIS transmitters.
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In my charmingly naive innocence I had assumed that the Glomex one was active. Which it must be, as it needs a 12V supply, but not active enough, it seems.
 
JumbleDuck said:
Fedex tracking shows my HP-33A moving steadily up Britain, so it's time to think about a VHF antenna for it. If I go for a second aerial (I'm still considering a Glomex splitter[1] and the masthead one, for simplicity and added range), I'd like a stubby one [2] on the rear pulpit. Metal mount, not plastic[3]. Any recommendations? I'm thinking of this one, also by Glomex[4]:


[1] Yes, I've seen the dire warnings about splitters, but since reattaching the aerial connection to the VHF in an emergency would be precisely the same amount of work as connecting the AIS aerial to the VHF in an emergency, I'm not too bothered.

[2] Appearance. Whip antennas low down are a bit "motorboat" for my taste

[3] I just don't like plastic brackets

[4] In the AIS frequency version
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I got the Glomex antenna and its performance on the pushpit was dire. It would only pick up ships a few miles away, usually long after I had seen them visually. Much of the port bow was completely blind. After one season I gave up with it and fitted a splitter to my masthead antenna and can now see coastguard shore stations well over 100 miles away.

Although it debatable whether it is worth being able to pick up stations 100s of miles away for anti-collision purposes, I find it quite useful because I can see any ships or coastguard stations that are in VHF hailing range.
 
I use my masthead for the AIS and have a whip on the back for the VHF (and can still pick-up Portland CG in Alderney).
 
Ric
Great mentioning your splitter but the transmission of AIS signals also comes into this thread since the OP has an AIS transponder...

Is yours a splitter of the 'active' variety.. ?
 
Slightly off topic but not too far, I hope. I bought an emergency VHF antenna many years ago, purpose made in a tubular container. I tried it with my SWR meter, which showed it to be a very poor performer, way over the recommended maximum value. It was far too late to return it so I am stuck with it.
 
If you want to do it on the cheap, you could strip back the coax from the ais and string it up the saloon bulkhead. You will get 5 or 6 miles on your ais. That's what I did before I got round to mounting an early version of the Metz Manta I picked up at a boat jumble many moons ago. It now sits atop my mizzen for ais / emergency vhf.
The joys of a 2nd mast :)
There's another thought, mount it on an aluminium pole at the pushpit!
 
I have my aerial mounted on a cut down extendable sailbord boom on the pushpit. The other half of the boom carries an active radar reflector
On my round UK trip my wife followed me via internet. She lost me in the middle of the legs from St peter port to Falmouth, & from Milford Haven to Dun Laghoire
i stayed in contact everywhere else. my transponder sites next to the VHF so in the event of a dismasting i can just plug the AIS aerial into the VHF
The boom fits to the pushpit with 2 U bolts
 
Daydream believer said:
I have my aerial mounted on a cut down extendable sailbord boom on the pushpit. The other half of the boom carries an active radar reflector
On my round UK trip my wife followed me via internet. She lost me in the middle of the legs from St peter port to Falmouth, & from Milford Haven to Dun Laghoire
i stayed in contact everywhere else. my transponder sites next to the VHF so in the event of a dismasting i can just plug the AIS aerial into the VHF
The boom fits to the pushpit with 2 U bolts
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Similar set up as Daydream believer, I have a 2 metre X 25mm pole mounted on a stanchion base on the deck and secured to the pushpit with 2 U bolts. It has a 2mm plate welded to the top to form a T and carries all the antennas; 2 GPS, AIS, Navtex and FM. All up out of harms way, the main VHF antenna is the only one at the top of the mast.
 
When I was installing my AIS transponder as a replacement to the 8-year old receiver-only last year I was tempted to buy a stubby version to replace the old receiver one on the wind generator pole. But then I bumped into the Italian Glomex manager in the marina who convinced me of the benefits of a 1/2 wave model (from his "30 years of installation experience" - "what is it you want, performance or convenience?").

So I installed the 1m Glomex on the pushpit on the same side as the wind generator pole. The results were poor and intermittent. As soon as I re-installed on the other quarter, still on the pushpit, away from the generator pole, the reception - both for my reception and the Marinetraffic receivers in Slovenia of my signal, 28nm away, improved dramatically. Here is a screen snapshot of OpenCPN showing targets anchored off Trieste, 30nm distant to my berth in my Italian marina.

GoT3.jpg
 
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Martin_J said:
Ric
Great mentioning your splitter but the transmission of AIS signals also comes into this thread since the OP has an AIS transponder...

Is yours a splitter of the 'active' variety.. ?
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Yes, I have Raymarine AIS transponder with active AIS splitter. I know also that the CG can see me when I am about 100 miles offshore, because I have tried radioing them for an "AIS check".
 
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