AIS - Easy installation on SO36i

[Trevor]

Hello all,

I recently installed a very inexpensive Automatic Identification System (AIS) receiver for our SO36i and thought others may be interested in the process.

It is now a legal requirement for all ships over 300 tons to have on board an AIS transmitter that provides quite detailed information to any other vessel that has the required receiving equipment. I purchased a Milltech SR161 AIS receiver from the Milltech website (http://www.milltechmarine.com/SR161.htm) for $189 and rate it as the best value for money I have ever spent.

The output of the SR161 goes directly to the NMEA port of the Raymarine E80 chartplotter. The output of the AIS receiver is set to 38,400 baud as standard and the chartplotter must be set to accept this data rate. This is done on the E80 by accessing the “system integration” menu.

I used to send GPS data to the VHF from the output of the chartplotter NMEA port for co-ordinates for the DSC system. When the baud rate was set to 38,400 this feature no longer worked because the standard NMEA rate is 4800 baud and that is what the VHF radio expected. I now take the GPS data from the NMEA output of the Raymarine SG1 autopilot computer and it works like a charm.

At first I tried to provide the AIS data to the NMEA input of the autopilot computer as I thought it would translate the information to the Seatalk network and the chartplotter would get the AIS information from the Seatalk network. Although I read as much as I could (read the manuals from cover to cover) no information on the translation of AIS data was available until I contacted the Raymarine technical support service. I was informed the chartplotter could only get the AIS data from the NMEA port. The manuals were not very detailed but the technical support service was extremely fast and very helpful. Congratulations to Raymarine for that service.

Also available from Milltech is a system for splitting into the existing VHF antenna on the yacht. I chose not to use that system as I simply used the rubber duckie antenna supplied by Milltech with the receiver. I figure I am only worried about ships that are close enough to run our yacht down so optimum long range reception is not a priority. The rubber duckie antenna works just fine and I can “see” ships 10 Nm from us.

The installation of the AIS receiver in the aft locker on our 2 cabin SO36i is shown below. Simply add power, put on the antenna and connect the serial port to the NMEA input on your chartplotter.



Below can be seen the chartplotter display of the information that is available from the receiver. The chartplotter indicates the heading and speed of the ship, its closest possible distance from our yacht if we both maintain current course and speed and the time that will occur. If the ship is regarded as a dangerous target as defined by user preset parameters on the chartplotter, alarms sound to alert the helmsman. The red circle indicates the 2 Nm exclusion zone can be seen around our yacht on the chartplotter.



This system can work for any modern chartplotter allowing for AIS data. I think the value for money is just outstanding and is an essential safety item for any offshore yacht.

Any questions or comments most welcome.

Regards,

Trevor

[sartine]

Hallo,
just to specify that the output baud rate of the sr 161 can be changed and adapted at chartplotters spec's via standard hyperterminal commands; this let the Sr 161 usable with all the chartplotters on the market including the Geonav 5 & 7 which requires 4800 baud rate commands

[Trevor]

Hello Sartine,

Very good point and in fact I set the baud rate to 4800 when I tried to use the autopilot to bridge the AIS receiver data output to the Seatalk network. Unfortunately the Raymarine product does not allow this to happen. On my particular Chartplotter it only accepts AIS data at 38400 baud.

Also to note that the instructions for changing baud rates etc come with the SR161 and are very easy to follow. One advantage of hooking a computer up to the data output of the AIS receiver is you can see the AIS data to confirm the receiver is actually working. This gives some confidence when setting up the chartplotter.

Happy sailing,

Trevor

[timturner]

Thank you Trevor for this idea. I have been considering doing it and so I looked to source a SR161 here in Britain. I emailed the company that makes them and so far I have had no reply, they do not list this item on their website. Has anybody out there been able to buy one in Britain? Thanks Tim

[Trevor]

Hi Tim,

If you use this URL
store.milltechmarine.com/smraaispr1.html you will go to the start of the ordering process for the SR161. Either that is simply google "Milltech SR161". You can simply get them to send the device to your home anywhere in the world. They are trustworthy and do what they can to help. I phoned them before making my order just to be sure they were for real and the guy who I spoke to was friendly and accommodating.

The device comes very well packed and the instructions are quite comprehensive.

I hope this helps,

Happy sailing,

Trevor

.

[mojo513]

Thanks for the very informative info. I have a RayMarine C80 chartplotter, but no radar yet. Do you think this rig will work without radar?

[Trevor]

Hello Mojo513,

The AIS system does not need radar to work. The output of the receiver simply goes into the NMEA port on the C80 and it will work and provide exactly the same display as on my E80.

I have no radar and have used this system to warn of ships that are too close to our yacht. It works very well indeed.

Good luck and happy sailing.

Trevor

[SO 36i - Penelope]

Hello,

I have just installed a SR161 AIS receiver in my new SO 36i. The receiver is connected to a VHF splitter (same Smart Radio brand). It is important to connect the VHF splitter on the same power as the VHF installation (in order to avoid damage to the splitter and AIS receiver). It works great and you can see all AIS transponding ships (even from far away due to high placed VHF antenna). I can reccommend it to anyone given the low cost and safety provided. Cost amount to EUR 169 for SR161 and EUR 129 for the VHF splitter (prices in The Netherlands)

The devices are installed behind the white board (above the switch board) )where all electronic cables and devices are located. The AIS receiver is connected to a Multiplex (shipmodule BT) device which send all information via bluetooth to the laptop which I use for navigation (Stentec WinGPS). The Multiplex sends (wireless) all Seatalk and NMEA data to the laptop, which plots the data on its screen.

Regards,

Ewald

[davideso37]

Hi all,

I am running a Rayamarine C80 in the cabin and a back up Digiboat on a PC. My VHF is an ICom unit. I was worried about splitting the VHF antenna signal but now both ICom and Comar Systems have combined AIS dual channel and antenna splitter units for around US$500. Both have dual outlets that will connect pc and plotters at the same time. I think the Comar would suit me as it has the NMEA 0183 for the C80 and the USB for the PC. If you were starting from scratch, ICom have a VHF unit with the AIS biult in. Any feedback on any of these systems would be appreciated.

Regards

David

[Trevor]

Hi David,

I am interested in your comment about splitting the VHF antenna. I am also not too keen on splitting the VHF antenna. For a start, the splitter must sense the VHF carrier when transmitting and disconnect the receiver from the antenna during this time. Otherwise you will have full transmit power on the receiver which would not be good. To do this some active circuitry is used to sense the carrier and make the switch. I see this as just one more thing to go wrong. Also, any of these RF switching devices in the RF path to or from the antenna can really only lead to losses that otherwise would not be there.

The other question is why does the AIS receiver have to be optimized for greatest range? Do we really care about a freighter that is 20 Nm away or is knowing about the one that is 10 Nm away sufficient. I have simply used the rubber duckie antenna that came with the SR161 on my boat. This keeps the two systems completely separate and provides me with AIS signals such that I can "see" AIS vessels 10Nm away. Given I am really only interested in vessels that are so close to be a threat, that is a fine outcome.

Having said all of that, the ICOM system that has it all combined in the one receiver is a brilliant solution and I think the best of all.

Regards,

Trevor

[no3l]

Hi, I am interested in fitting the SR161 but when I checked the website using the link in the thread it states that it is not suitable for NMEA connection to chartplotters.

Quote from site "The SR161 can be used with navigation computers, chart plotters and multiplexers that support connections using an RS232 serial port interface. This product is not designed to be interfaced with NMEA RS422 chart plotters."

Also in the illustration it doesn't show the stub aerial, is this supplied as standard?

Regards
Noel

[Trevor]

Hi Noel,

I have since sold the yacht but every now and again I look across the forum and as this one refers to one of my projects I thought I would "come out of retirement".

The NMEA standard refers to the protocol (digital "words" that make up the message) and not the physical electrical interface. The RS232 or RS 422 refers to the electrical interconnection standard. The RS232 refers to an unbalanced method of connection. The RS422 refers to a balanced method of connection.

Some interfaces are RS232 and some others are RS422. For instance the serial port on a laptop will usually be RS232.

The website says the device is suitable for NMEA RS232 devices and not NMEA RS422 devices. Ok having said that I have a sneaking suspicion the Raymarine NMEA input is actually an RS422 specified interface but the output of the SR161 fed that interface without a problem. The reason is the RS422 standard has a lower voltage threshold than the RS232 standard. The RS232 output of the SR161 can drive the RS422 input but it could not work the other way around.

The disclaimer merely indicates that the output of the device is not a balanced output and therefore may not have the same noise immunity that a proper RS422 output would give for RS422 devices.

To cut to the chase, it worked perfectly well in my case and it should do so you as well.

The antenna came in the box with mine but you can simply buy the VHF antenna on the website when you buy the SR161.

Happy sailing,

Trev

[no3l]

Hi Trev
thanks for the clarification, looks like I have a nice project for the winter.
Fair winds
Noel

[hstanley01]

Very useful Trevor .

How did you get into the back of your Navpod when you installed the intrument array a few years ago ? . There are some special nuts on the back of my navpod - like"car wheel nuts" that come with mine , I imagine they are standard on all SO36is .It looks to me like a security feature .

[Caxton]

Another option now available for pretty low cost, is installing a VHF with GPS/AIS and connect the NMEA AIS out of the VHF to the Chartplotter.

I bought a Standard Horizon GX2200 for $340, the Raymarine E80 NMEA out cable, shielded 24guage wire (the NMEA cable won't reach the VHF), Some 3M Scotchlock UR connectors and it worked like a charm.  I used some fiberglass wire fishing  push pull rods to run the cable from the plotter to the VHF.  As a note, I didn't use the NMEA out from the Chartplotter for GPS as the VHF has its own GPS and it worked fine from the nav station in the salon.

If you buy the GX2200, one annoying thing was I had to buy the Standard STD-MMB-84 Flush Mount for $20 which should have been included with the VHF.

I had TAP plastics cut me a plastic template face cover to cover up the larger hole that the ICOM 504 I replaced, attached is a picture.



Attachment Deleted

Cheers,

Caxton

[alex1949]

Hi folks,

I installed the ICOM MXA5000 Ais receiver on board my boat.

It comes with an integral antenna splitter. Very easy to install DIY,works fine and allow me on clear days an Ais view of 150 NM.

For the 275 $ it's really a great value as all stated .

Highly recommended.

[lateron]

I have a Digital Yacht combo chartplotter in the cockpit with AIS reception which works brilliantly and is invaluable in the North Sea areas I sail. But although it has an AIS out I cannot get it to talk to my Garmin 55 plotter down at the chart table, nor will NMEA send and be received either . My Garmin has both kinds of NMEA reception but I and an electronics engineer have tried and we cannot crack the send/receive. Any ideas anyone?
Thank you Ron

[Don Reaves]

The NMEA input and output speeds are different. Be sure to check that in the setup for all connected devices.

(I suppose you've already done that, but it can't hurt to mention it.)

[lateron]

Hi Don......I'm pretty sure we had both sender and receiver working on the same NMEA. It's rather frustrating ....the engineer took my Garmin away to check it and it did speak to eg an Icom vhf but it wouldn't speak to a Simrad VHF on my boat and neither would it receive NMEA or AIS from the Digital Yacht plotter combo. He said it may be that the NMEA sentences are not quite the same !!!
I thiught NMEA would be an industry standard but apparently not?
Cheers Ron

[Trevor]

Hello all,

Its a long time since I have seen this thread! Firstly apologise to hstanley01 because i don't remember answering that query from 2011. I figure that issue must now be resolved . Secondly, I must agree with caxton as those Standard Horizons HF radios are amazing value.

I have a AMEC Camino 108W AIS on the boat now which has the Class B transponder built in.

AIS is just an amazingly effective anti-collision device for the price.

Regards,

Trevor

[vasko]

When I got my boat she was with spanish flag and I changed to UK and old dsc vhf was for the bin ... e. I neeeded a new vhf and i got ST matrix with AIS and RAM3 remone for the helm - all works lika dream and very easy install all vonected to my Garmin GPS map too I sea AIS to about 30nm in all devices RAM3. VHF and Chart plotter with all alrrms etc ... now installing a AIS transponder... described in another thread

[MalcolmP]

Scherbe a knowledgeable SO36i owner has just sent me the following useful image and wiring diagram for an Easy AIS on his SO36i




www.dropbox.com/sh/gompilv1byudvwl/AAAxrDux7oyB7_BjgVnIpfjKa?dl=0

[ForGrinsToo]

For Grins Too is a 36i with the Matrix 2150 dual-channel AIS receiver. While I thought about upgrading to the new GPS-equipped version (Matrix 2250 at about $400 from Defender), I've been happy using an older Garmin GPSMAP 76 to supply lat/lon to the 2150. One upside is that I can drop most electrical load at anchor, use the 76 for anchor watch - with track display and internal battery-backup. Based on information from this and other forums, I bought a Brookhouse iMux WiFi multiplexer which sends everything (including SeaTalk) to an iPad and INavX. So far, the AIS sentences don't transfer but Brookhouse has made a couple of suggestions, having specifically tested the iMux with the 2150. We know it can work, but we're three weeks from launch and test.

OpenCPN supposedly can accept all that data via WiFi, so using a Win XP laptop as a chartplotter in the cabin as well as the iPad at the helm are the two goals.

Why a Win XP laptop? If it's getting 13VDC from the house it doesn't use the internal battery. At 12.4 - 12.6 it's still pulling from the house but flags the external supply as disconnected. Below 12.4, the laptop pulls from its internal battery. Anything newer wants 18V, or more, and I'm not about to install an energy-wasting invertor. If I can convince the Admiral, we'll get another iPad. On the other hand, if we want to watch a movie, the laptop is perfectly adequate.