Standard Horizon GX2200 - pre-purchase questions

[webcraft]

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I know quite a few of you have fitted these, just want to pick your brains.

a) Flush mounted down below, what chance of the internal GPS picking up a signal? (Have a nearby GPS172 I can connect to, looks simple enough)

b) Is it easy to send the AIS data to a plotter ? (Garmin 620)

c) I have seen suggestions that you can also sent DSC data to a plotter - why would you want to do that?

d) At some point in the future I may want to fit an AIS transceiver - I am assuming I would have to then disable the AIS on the GX2200, or I would be constantly picking up my own signal and causing electronic collision panic?


- W

 

[prv]

a) Flush mounted down below, what chance of the internal GPS picking up a signal? (Have a nearby GPS172 I can connect to, looks simple enough)

Very good, I think, unless your boat is steel (and quite possibly even then).

b) Is it easy to send the AIS data to a plotter ? (Garmin 620)

As easy as any other AIS receiver would be.

c) I have seen suggestions that you can also sent DSC data to a plotter - why would you want to do that?

Assuming the plotter understands the DSC messages and does something sensible,

• if someone transmits a DSC distress message, their position will be shown on the plotter allowing you to see that they're nearby and you may be able to help (or that they're not nearby and there's no point you noting down the details or plotting the position)
• you can do a "position poll" of another vessel you're sailing in company with (or otherwise interested in) and see where they are. Or you could just phone them and ask, of course.

I'm not convinced that either of these are really a compelling case . The first is mildly useful enough that I'd make the connection assuming a port was available, but I wouldn't start buying multiplexers and suchlike to make it possible.

d) At some point in the future I may want to fit an AIS transceiver - I am assuming I would have to then disable the AIS on the GX2200, or I would be constantly picking up my own signal and causing electronic collision panic?

I don't know exactly.

The radio knows your MMSI, so in theory ought to be able to recognise that the signal is your own position rather than another boat. In an ideal world it would then emit it as a VDO ("own vessel") sentence rather than the normal VDM, but I'm not convinced it's that clever.

The Garmin presumably doesn't know your MMSI, so can't do anything clever with the information about a "very nearby" boat if it comes in a VDM sentence.

The radio's own AIS alarms are pretty basic, so even before getting the transmitter I would use it as a data source only, disable the alarm function, and use the alarms in the plotter (though I don't know how sophisticated a Garmin 620 would be either, at least it's probably easier to cancel false alerts).

If you get the transmitter and the plotter does raise false alarms for your own boat using the AIS data from the radio, instead of turning off AIS on the radio I would re-wire the plotter to get AIS data from the new transmitter instead. Leaving AIS reception enabled on the radio (with alarms disabled) will allow you to choose a nearby vessel from a list to send a DSC call to.

Pete

 

[webcraft]

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Thanks Pete, all very interesting. The only thing I am still unclear about is the implications of fitting an AIS transponder and leaving the AIS switched on on the radio - even with the alarms disconnected. I understand this is a good way of transmitting a DSC message directly to a dangerous target, but will the display on the radio always show my boat right in the center of the screen? It;s a tiny screen, so this wojld not be very helpful.

Has anyone on here actually fitted a transceiver with a pre-installed GX2200 ? You would also need to bypass the aerial splitter if you wanted to use a splitter for a transponder - is this possible ?

Pity there isn't a version of this radio with an AIS transceiver . . .


- W

 

[lpdsn]

I answer as the owner of a Gx2100, so I can't answer a). The rest of the radio is the same though.

b) AIS data comes out on it's own NMEA wires at 38.4Kb. So if the plotter can read VDM sentences and can take input at 38.4Kb then it is easy. Beware that there are 20-odd types of VDM sentence so not all plotters understand all messages, but that is not necessarily an issue.

c) I send the DSC & DSE messages to OpenCPN. I think prv has it right. The messages give useful features, but if you have to go far out of your way to get them through it maybe isn't worth it.

d) Difference in price between a Gx2200 and the SH VHF DSC radio is significant, so if you are looking at an AIS transceiver maybe better to save some money and get the standard radio (Gx1700 I think is the latest).

In general I'm really impressed with how well the Gx2100 works as a VHF radio, so I've turned into a bit of an advocate of Standard Horizon VHFs.

 

[lpdsn]

You would also need to bypass the aerial splitter if you wanted to use a splitter for a transponder - is this possible ?

Pity there isn't a version of this radio with an AIS transceiver . . .

If you fit a transceiver you'll need a separate aerial not a splitter.

Is the Gx6500, or whatever they call it, not out on the market yet? Anyway, if you want one of those you could start preparing now by filling out the paperwork for the IMF loan. Once fitted it would make it easier to sell your boat. Just put out an advert for a Gx6500 for sale with boat still attached.

 

[prv]

will the display on the radio always show my boat right in the center of the screen? It;s a tiny screen, so this wojld not be very helpful.

Seems like it would; again we don't know whether the radio uses its knowledge of the MMSI to recognise AIS messages that relate to yourself.

I've never even attempted to use the AIS screen on the radio - at least in this part of the world it's far too small to be usable whether or not there's a spurious target in the middle of it. I regard the AIS part of the radio as purely a black-box receiver, and deal with all the data on another display (originally a Vesper Watchmate, now also a newer Raymarine plotter).

I could see using the radio AIS standalone on an ocean passage, with the plotter shut down as not needed for navigation, and all you need from the AIS is a simple alert that the occasional ship is in the vicinity. But for coastal collision avoidance work it's not really usable.

You would also need to bypass the aerial splitter if you wanted to use a splitter for a transponder - is this possible ?

I don't know what splitter you mean. The GX2200 does all its combining of functions electronically inside the box.

Talk of splitters does throw up an interesting point though - if you were to use one when you fit the transmitter, I don't think the gx2200 would ever see the confusing own-ship transmissions in the first place, because it would be disconnected from the antenna when they are being sent out.

Pity there isn't a version of this radio with an AIS transceiver . . .

They do have the GX6500 at trade shows and lent to reviewers, but not on public sale yet. However, for some irritating reason it uses a separate antenna for the AIS and VHF, thus losing the main benefit of an integrated set.

Pete

 

[prv]

If you fit a transceiver you'll need a separate aerial not a splitter.

Splitters suitable for transmission are available. They disconnect the other unit (I assume physically via an RF-rated relay, though I'm not sure) when one of them transmits.

Pete

 

[webcraft]

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Hmmmmm . . .

Lots to think about. Thinking of a cheaper radio now and the Masutec33A (standalone AIS display) with Vesper splitter.

I do fancy a fixed VHF with built in GPS though, as one less thing to wire.



- W

 

[bedouin]

Talk of splitters does throw up an interesting point though - if you were to use one when you fit the transmitter, I don't think the gx2200 would ever see the confusing own-ship transmissions in the first place, because it would be disconnected from the antenna when they are being sent out.

I'm not expert but I suspect it would pick up a transmission that close without an antenna

 

[webcraft]

I'm not expert but I suspect it would pick up a transmission that close without an antenna

Interesting.

Overall it looks like it would be better to bite the bullet and fit a transponder and non-AIS radio. Just have to go sell my body down the docks.

- W

 

[PaulRainbow]

Interesting.

Overall it looks like it would be better to bite the bullet and fit a transponder and non-AIS radio. Just have to go sell my body down the docks.

- W

That would be my suggestion, or just stick with receive only AIS.

 

[tross]

I have had a GX2200 fitted to my boat for a couple of years new and it has worked well with my Raymarine MFD both for AIS and DSC functions This year I wanted to add a Class B transmitter but didn't like the look of the splitters or fixing another Ariel. What Raymarine have just released is a AIS Class B with a splitter included. This fixed the problem in one go - ClassB and no seperate slitter or Ariel. I also have the fall back that if it fails I can eaily revert back to the old system by just moving the ariel cable and flicking the NMEA output on the GX2200 back to 38,000 ( if you use 4800 it only sends the DSC sentences)

hope that helps
Tross

 

[noelex]

We have an AIS transponder (Vesper) and an AIS receiver built into the VHF (Icom M506). I think this is a good set up as the VHF provides back up AIS information on a totally independent system (other than the battery supply). The extra cost of an AIS receiver incorporated into the VHF is not high.

The system can be programed so that recognises itself and does not think a collision is imminent.

 

[[70521]]

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I do fancy a fixed VHF with built in GPS though, as one less thing to wire.

I have the SH 1700 for that very reason, the old GPS to VHF was always losing its position and I wanted to know that when the wee red button was pressed my position would be sent.

 

[Irish Rover]

I fitted a SH2200 to my boat yesterday. I haven’t figured out yet how to connect it to Garmin 820xs chart plotter but I’m sure I’ll figure it out when I read but manuals. I’ve not had any AIS capability before apart from the Marine Traffic app on my tablet so I’m trying to figure out the best settings. The range is set at 10nm but I’m trying to figure out what settings I should have for CPA and TCPA alarms. I don’t want it beeping every time something with a transceiver appears on the horizon. Any advice appreciated and if anyone happens to know off hand which color wires I need to connect on the 2200 and G820 it would save a tech numpty a lot of head scratching.

 

[[70521]]

I have a different AIS transponder but ALL of the alarms are off! If I am that close then I've been sleeping for far too long.

Your manuals should inform you of what colour cable is in and out for the data. One day I might get round to displaying the AIS data on the chart plotter but it is not high on my to do list.

 

[RichardS]

Interesting.

Overall it looks like it would be better to bite the bullet and fit a transponder and non-AIS radio. Just have to go sell my body down the docks.

- W

When it comes to displaying AIS targets, it seems that not all displays are equal. My Vesper Marine transceiver is connected by NMEA to my elderly Raymarine plotter and also transmits the same AIS data by wifi so I can see it on my tablet or laptop running the Vespermarine app or OpenCPN program/app depending on which is closer to hand and not already in use for something else.

The AIS targets on the Raymarine, especially the more distant ones, quite often disappear and then re-appear a minute or two later. However, as they are perhaps more than 5 miles away it's not a problem. The targets on the VM app or OpenCPN are rock solid from 30 miles away to the point where they are going to take me out and I've never seen one vanish. Probably better software on the newer devices.

Richard

 

[prv]

The AIS targets on the Raymarine, especially the more distant ones, quite often disappear and then re-appear a minute or two later. However, as they are perhaps more than 5 miles away it's not a problem. The targets on the VM app or OpenCPN are rock solid from 30 miles away to the point where they are going to take me out and I've never seen one vanish. Probably better software on the newer devices.

Whether the targets are detectable or not at long range is purely a function of the receiver, which all three of your devices are sharing. What it sounds like is happening is that the Vesper and OpenCPN are set to keep displaying a target they are no longer actually receiving, for longer than the Raymarine. In a sense the Raymarine is rendering the situation more accurately, while the others are showing you out-of-date information. Of course maybe that’s more useful in practice.

Next time it happens, have a look at the data age figure for those targets on the Vesper and OpenCPN. That vessel might have last been seen five minutes ago and a fast one could be somewhere else by now.

Pete

 

[Heckler]

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I know quite a few of you have fitted these, just want to pick your brains.

a) Flush mounted down below, what chance of the internal GPS picking up a signal? (Have a nearby GPS172 I can connect to, looks simple enough)

b) Is it easy to send the AIS data to a plotter ? (Garmin 620)

c) I have seen suggestions that you can also sent DSC data to a plotter - why would you want to do that?

d) At some point in the future I may want to fit an AIS transceiver - I am assuming I would have to then disable the AIS on the GX2200, or I would be constantly picking up my own signal and causing electronic collision panic?


- W

Mine is fitted below, Bene 381, picks up gps and ais perfectly, squirt all the data thru a vyachtwifi widi transmitter and overlay on Opencpn or any of the apps that can display it, interesting data in the Straits of Gibraltar!
I bought a ram mike ext to work it from the cockpit. superb bit of kit. My mate here in Faro bought a Vesper, still hasnt got it working correctly! He called them and they said send it back for them to check. To New Zealand!

 

[lpdsn]

Next time it happens, have a look at the data age figure for those targets on the Vesper and OpenCPN. That vessel might have last been seen five minutes ago and a fast one could be somewhere else by now.

Pete

He could also configure how long OpenCPN displays targets after the last sentence was received (I prefer them to stay there for a while so at least it's obvious there's something out there somewhere). OpenCPN will also draw a line through older contacts that it hasn't removed. Again the timing of that is configurable. Good for warning of old data.