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Refueler

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The op wanted examples of receive only as well as transceiver , so I gave them one. Their vague OP with no budget etc . Their choice to make. Having receive only may be what they want even if you don’t. Maybe it is all they can afford …… although someone posted an Aliexpress or Alibaba colour transceiver for a cheap price.

You say I have no idea how a splitter works. Isn’t that a bit of a rude thing to say , Especially as you don’t know me ?
You flick a switch and can’t use your vhf any longer. Flick it again and have vhf but NO AIS. Some people don’t like splitters for that reason. I picked that view up from this forum many years ago. some people dont like splitters for that reason ONLY…..

I also did not say to mount antenna on a rail…….you must have assumed that. a proper installation would be a 2nd antenna mounted high up but not so as to interfere with vhf radio antenna ….. hence no splitter …. again.

You must be happy to have vhf and no AIS or AIS and no vhf if you are using a splitter?

I know quite a bit about vhf antennas and have even tuned some for my own reasons. I bought a metz many years ago and can verify the swr is better than any antenna I had previously. I used my splitter (the thing you say I know nothing about) to connect 2 antennas to one radio or dummy load and swr meter etc etc). I wish people would be more polite in their posts. I do know how a splitter works you see , in-spite of your view. Sorry to contradict you .

You can use this equation below to calculate your ‘huge margin’ and edit your post to be more accurate and give an actual measurement in miles rather than stating a vague ‘huge margin’ if you like ….. that would give the OP some useful info (making the assumption that they don’t know the height advantage ….. and it is not good to make assumptions very often ….. can lead to posts appearing rude or insulting)

(√antenna height) * 1.23 = radar horizon

E.g. Sq root 25 * 1.23 = 6
as opposed to sw root 1 * 1.23= 1.23 for pushpit mount

Hope this post clarifies any assumptions made.
1. I have compared splitter vs no splitter .... on same masthead antenna ..... difference even with my PASSIVE splitter was negligible.
2. Splitters default to priority VHF .. so we can put that bit to bed.
3. If you use a Powered splitter - the results are way better than any standalone unit because the powered splitter makes up for cable losses far better.
4. You cannot - if you want non interference use of BOTH antennas - have them at masthead ... Suggest you check up the specified minimum distance in ALL directions to maintain between two VHF frequency band antenna ... AIS and VHF.
5. You may think I was rude - your choice. I was stating fact about splitters. I am fully entitled as you are also - to have differing viewpoint... and to voice such. I did not use rude or insulting words / grammar.
6. Yes I assumed rail mount as OP will be looking for simple budget setup as per his posts ... rail would be logical. That would increase the reduction in received targets compared to a splitter masthead setup.

No need to try and impress with formulae .... as its a practical matter and easily demo'd in literally every marina .... as there will be plenty of variation in setups ...
 

OCuea

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1. I have compared splitter vs no splitter .... on same masthead antenna ..... difference even with my PASSIVE splitter was negligible.
2. Splitters default to priority VHF .. so we can put that bit to bed.
3. If you use a Powered splitter - the results are way better than any standalone unit because the powered splitter makes up for cable losses far better.
4. You cannot - if you want non interference use of BOTH antennas - have them at masthead ... Suggest you check up the specified minimum distance in ALL directions to maintain between two VHF frequency band antenna ... AIS and VHF.
5. You may think I was rude - your choice. I was stating fact about splitters. I am fully entitled as you are also - to have differing viewpoint... and to voice such. I did not use rude or insulting words / grammar.
6. Yes I assumed rail mount as OP will be looking for simple budget setup as per his posts ... rail would be logical. That would increase the reduction in received targets compared to a splitter masthead setup.

No need to try and impress with formulae .... as its a practical matter and easily demo'd in literally every marina .... as there will be plenty of variation in setups ...
I’ll bite ….. alas. To address your quotes…..
4. Where did I say both antennas at masthead? Everyone knows that is untenable. Hence I did not say it.

5. if you think it is not rude to tell someone they have no idea how a piece of equipment works then crack on. I would not even think of saying to someone ‘you don’t know how such and such works’

6. making assumptions is not always a good idea yet you admit you did it.

You think I am trying to impress you? With an equation every sailor with a radio should know? Nope.

I don’t like being told that i have no idea how something works when I do know….. would anybody like to be told that?

Should I say you have no idea how to make remote controlled aeroplanes? Of course I wouldn’t.

Out.
Dangle more bait and I’ll pass.
 

Sea Change

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I did not know that you couldn't use two masthead antennae. And I did use two, for about four years, one for VHF and one for AIS. Both seemed to work perfectly.
 

PaulRainbow

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You say I have no idea how a splitter works. Isn’t that a bit of a rude thing to say , Especially as you don’t know me ?
You flick a switch and can’t use your vhf any longer. Flick it again and have vhf but NO AIS. Some people don’t like splitters for that reason. I picked that view up from this forum many years ago. some people dont like splitters for that reason ONLY…..
I'm puzzled, what switch is being flicked ?
 

Dellquay13

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The op wanted examples of receive only as well as transceiver , so I gave them one. Their vague OP with no budget etc . Their choice to make. Having receive only may be what they want even if you don’t. Maybe it is all they can afford …… although someone posted an Aliexpress or Alibaba colour transceiver for a cheap price.

You say I have no idea how a splitter works. Isn’t that a bit of a rude thing to say , Especially as you don’t know me ?
You flick a switch and can’t use your vhf any longer. Flick it again and have vhf but NO AIS. Some people don’t like splitters for that reason. I picked that view up from this forum many years ago. some people dont like splitters for that reason ONLY…..

I also did not say to mount antenna on a rail…….you must have assumed that. a proper installation would be a 2nd antenna mounted high up but not so as to interfere with vhf radio antenna ….. hence no splitter …. again.

You must be happy to have vhf and no AIS or AIS and no vhf if you are using a splitter?

I know quite a bit about vhf antennas and have even tuned some for my own reasons. I bought a metz many years ago and can verify the swr is better than any antenna I had previously. I used my splitter (the thing you say I know nothing about) to connect 2 antennas to one radio or dummy load and swr meter etc etc). I wish people would be more polite in their posts. I do know how a splitter works you see , in-spite of your view. Sorry to contradict you .

You can use this equation below to calculate your ‘huge margin’ and edit your post to be more accurate and give an actual measurement in miles rather than stating a vague ‘huge margin’ if you like ….. that would give the OP some useful info (making the assumption that they don’t know the height advantage ….. and it is not good to make assumptions very often ….. can lead to posts appearing rude or insulting)

(√antenna height) * 1.23 = radar horizon

E.g. Sq root 25 * 1.23 = 6
as opposed to sw root 1 * 1.23= 1.23 for pushpit mount

Hope this post clarifies any assumptions made.
Reading your description of a splitter, I think you may have not seen some of the passive splitters available. I have an EasyAIS splitter (unamplified and AIS receive only, needing a 12v supply) which connects both vhf and AIS to the antenna in normal state but disconnects and protects the AIS receiver when it detects vhf tx. It doesn’t have any manual switching. Other brands of auto sensing passive splitters are available.
 
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Refueler

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Reading your description of a splitter, I think you may have not seen some of the passive splitters available. I have an EasyAIS splitter (unamplified and AIS receive only, needing a 12v supply) which connects both vhf and AIS to the antenna in normal state but disconnects and protects the AIS receiver when it detects vhf tx. It doesn’t have any manual switching. Other brands of auto sensing passive splitters are available.

That's an Active Splitter - powered.

Passive is unpowered.
 

ears media

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And of course the AIS gets back into the comms radio. My AIS has been on 24/7 for years sharing a mast with an Icom comms radio and another Icom that does business radio. The AIS desenses comms traffic every burst but that doesnt matter. Modern radios don’t seem fragile to RF any longer.

Two resonant antennas in close proximity do distort the polar patterns, acting as reflectors/directors if close but few people ever notice the beaming and nodes created.
 

Refueler

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And of course the AIS gets back into the comms radio. My AIS has been on 24/7 for years sharing a mast with an Icom comms radio and another Icom that does business radio. The AIS desenses comms traffic every burst but that doesnt matter. Modern radios don’t seem fragile to RF any longer.

Two resonant antennas in close proximity do distort the polar patterns, acting as reflectors/directors if close but few people ever notice the beaming and nodes created.

May I suggest you consider your AIS and what 25W via the VHF can do to it ? The VHF is fine with the 2W - 5W AIS ... its the 25W I'd be concerned about.

I would also suggest that given the limited amount of time on VHF - that the short occasional burst of energy is accepted - but I wonder what a long sustained burst might do ?

VHF / AIS specs make it clear to have that separation of antenna that masthead cannot provide.
 

Allan

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I feel I need to mention this somewhere, sorry for the thread drift. I have a tablet with Navionics as an independent backup to our boat system. When I decided to add an AIS receiver, I contacted Aves marine on their technical phone number. I received a Quark A026 very quickly from what appears to me to be a great company who I wholeheartedly recommend.
Allan
 

AntarcticPilot

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Internet AIS poroviders specifically warn that data of a vessel may be old ...

We use Marine Traffic in our work and frequently find this - even though we are pro licenced users.
Not merely old, but also incorrect. MarineTraffic often shows my boat as being at Grimsby; it has never been there. This is most likely because someone has put my MMSI in the app.

The internet apps are great for allowing friends and family to see where you are, but dangerous for real-time navigation.
 

dgadee

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The internet apps are great for allowing friends and family to see where you are, but dangerous for real-time navigation.
True. My AIS wasn't properly connected up and I was using MarineTraffic on my phone. I was going from Donaghadee to Portpatrick but there was thick fog. I went back to the house (it overlooked the sea) and saw that it was beginning to clear so went down to the boat and set off (it is a quiet piece of sea). About a mile or two out it came down again, very thick, but I went on. On my phone I saw via AIS a ship coming down the north channel. I thought - I will keep an eye on it on my phone App. Well, halfway across this vessel - travelling at full speed - must have missed me by a very short distance indeed. The bow wave lifted me up and its horn went off really loudly. Never saw it. The closest thing I have ever had to a collision at sea. They talk about radar assisted collisions. This was an Android assisted near one.
 

PabloPicasso

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What is, how much, is the cheapest stand alone AIS setup I can get for my 29ft sailing boat. I have a small gantry on the back for mounting aerials/antenna. I realise the range will not be as good as a top of the mast one but it will have to do fo

What is, how much, is the cheapest stand alone AIS setup I can get for my 29ft sailing boat. I have a small gantry on the back for mounting aerials/antenna. I realise the range will not be as good as a top of the mast one but it will have to do for now.
Please see the PM I've sent you
 
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