AIS Em-trak 2W or 5W?

[RunAgroundHard]

Trying to decide on a 2W or 5W AIS unit from Em-trak. The obvious difference is price as the 2W are lower cost. The next obvious difference is power and range that my AIS signal will be picked up from farther away if the 5W power is selected.

I will be purchasing an integrated splitter model and use my VHF antenna, 15m up the mast. I sail mostly in and around the the islands, lochs, mountains and headlands of the WCoS. Later long distance sailing across open water to Norway, Iceland and more islands, fiords, mountains and headlands,

Question: Will the 5W model be more visible around the headlands and hills of Scottish waters, than the 2W model, or does it not matter if line of sight is blocked by natural features what the power rating is? In open water, will 2W be a suitable for range. accepting a shorter time to detect is a risk. And final question, receiving AIS signal from other vessels is not dependent on my AIS unit power range i.e. it is not more sensitive to picking up signals because it is 5W and not 2W?

 

[Roberto]

I'd see two advantages: the 5W will be SOTDMA, maybe not interesting to you in remote areas but definitely useful in areas with a lot of traffic; the 5W can usually enable long range 'message 27' which makes you a lot more visible to sat-Ais, which of course is not influenced by topography or absence of coastal receiving stations in case you want family/friends to follow you through MarineTraffic etc.
I have a B-cstdma bought when B-sotdma did not exist, should I buy one today I would definitely go for Sotdma for the first reason; (MarineTraffic many people love it, I have idiosyncratic hatred )

 

[st599]

VHF is sort of line of sight, but you can get multipath where it bounces off things and it can diffract slightly around objects.

Transmitter power doesn't affect receiver sensitivity.

The additional power doesn't change the radio horizon, just makes it more likely there'll be enough power at the receiver to be decodable.

 

[Roberto]

Also consider antenna installation: if you choose the masthead, better take a low loss coax cable/connectors otherwise once at the masthead your 5W might be degraded to 2ishW, (or not much left to radiate if the txr sends 2W).

 

[jwilson]

I have had an Emtrak 5W with built-in splitter for 3 years which all works very well. It did fail once when under a year old, and Emtrak were ultra-efficient in fixing it.

 

[RunAgroundHard]

Thanks. I bought from Salty_John the Metz antenna and quality coax and fittings as advised, some years ago. Hopefully the installation is still good.

I’ll go for the 5W model. Appreciate the advise.

 

[PaulRainbow]

Thanks. I bought from Salty_John the Metz antenna and quality coax and fittings as advised, some years ago. Hopefully the installation is still good.

I’ll go for the 5W model. Appreciate the advise.

If you need any further help, i'm an Emtrak dealer.

 

[KompetentKrew]

the 5W will be SOTDMA, maybe not interesting to you in remote areas but definitely useful in areas with a lot of traffic;

The B+ also transmits the message 27 which can supposedly be seen from space, so possibly also useful for those who go off the beaten path. Your loved ones should be able to find you on MarineTraffic even when you're well offshore, although I have not tested this.

Previous discussion of message 27 and satellite AIS

 

[Roberto]

The B+ also transmits the message 27 which can supposedly be seen from space, so possibly also useful for those who go off the beaten path. Your loved ones should be able to find you on MarineTraffic even when you're well offshore, although I have not tested this.

Previous discussion of message 27 and satellite AIS

Yes I wrote that in message #2 of this thread, plus #5 in the same 2022 thread. I should stop stammering
AIS via Satellite

 

[KompetentKrew]

Yes I wrote that in message #2 of this thread, plus #5 in the same 2022 thread. I should stop stammering
AIS via Satellite

Sorry, have been procrastinating over new glasses. I really should get on it.

 

[RunAgroundHard]

Purchased the Em-Trak B953 AIS and fitted it today. An easy set up, plug in the Raymarine STNG spur to the backbone, power cable to the plotter breaker, with a 3A fuse, negative to the common bus, antenna and VHF cables plugged in, bobs your uncle.

I forgot my USB crossover cable for the iPad, so will need to enter vessel details next visit. Powered it all up and off it went transmitting and receiving. Alarms working!

Extra Items
1. STNG 3m backbone cable (blue, black).
2. STNG x DeviceNet (AIS end) spur cable.
3. STNG 5 Way Converter
4. 1x STNG Terminator
5. 2 x STNG blanking plugs.
6. 3A blade fuse.

My VHF, Standard Horizon GX1850GPS/E, on powering up, defaulted to receiving GPS from NMEA2000 rather than internal. As that was not set up, no GPS on VHF. The manual was needed to select internal GPS as I prefer the VHF to be standalone. Easy sort, but without the manual the menu descriptions were quite cryptic and impossible for me to work out what had to selected.

I will fit the silent mode switch later, but want to get the same style as my breakers and conveniently the switch panel has one spare bay. The hardest bit was the usual running cables from behind the instruments in the cockpit, to the switch board. Also mounting location because on the top there are two coaxial cables, and on the bottom STNG and Power Cable gland. These protrude about and extra 4 to 5” and require space as they are stiff. I’ll now review the Axiom manual et cetera to ensure all alarms and functions are used correctly.

A big thanks to everyone for advice and especially to @PaulRainbow for his assistance.

Now that I have an STNG 5 Way Converter at the switch panel (for Radar next). I will look at rationalising the network and simplifying it.

 

[Alicatt]

We (I) fitted an Em-Trak B952 AIS to the boat last summer to be able to take our boat through Antwerp, I get results from 30+km from the boat which is sitting in a canal in Belgium just now, boat is surrounded by trees and with a 5/8ths antenna it is giving great results once I sorted out the antenna cable.
It is connected via NMEA2000 to the Simrad Go9 on the upper helm and a Garmin Echomap 95SV at the lower helm, and has a GPS mushroom on the radar arch, (just behind the loudspeaker) for it's position and the port antenna to transmit and receive VHF data, Starboard is for the VHF radio

We had a bit of a storm recently so plenty of mooring lines

 

[PaulRainbow]

Purchased the Em-Trak B953 AIS and fitted it today. An easy set up, plug in the Raymarine STNG spur to the backbone, power cable to the plotter breaker, with a 3A fuse, negative to the common bus, antenna and VHF cables plugged in, bobs your uncle.

I forgot my USB crossover cable for the iPad, so will need to enter vessel details next visit. Powered it all up and off it went transmitting and receiving. Alarms working!

Extra Items
1. STNG 3m backbone cable (blue, black).
2. STNG x DeviceNet (AIS end) spur cable.
3. STNG 5 Way Converter
4. 1x STNG Terminator
5. 2 x STNG blanking plugs.
6. 3A blade fuse.

My VHF, Standard Horizon GX1850GPS/E, on powering up, defaulted to receiving GPS from NMEA2000 rather than internal. As that was not set up, no GPS on VHF. The manual was needed to select internal GPS as I prefer the VHF to be standalone. Easy sort, but without the manual the menu descriptions were quite cryptic and impossible for me to work out what had to selected.

I will fit the silent mode switch later, but want to get the same style as my breakers and conveniently the switch panel has one spare bay. The hardest bit was the usual running cables from behind the instruments in the cockpit, to the switch board. Also mounting location because on the top there are two coaxial cables, and on the bottom STNG and Power Cable gland. These protrude about and extra 4 to 5” and require space as they are stiff. I’ll now review the Axiom manual et cetera to ensure all alarms and functions are used correctly.

A big thanks to everyone for advice and especially to @PaulRainbow for his assistance.

Now that I have an STNG 5 Way Converter at the switch panel (for Radar next). I will look at rationalising the network and simplifying it.

Glad it all well well for you. FYI, the radar doesn't connect to STNG, it's Raynet. It comes with the cable, just plugs into the back of the Axiom.

 

[[164147]]

If you have an Axiom you should be able to put the AIS into silent mode from it.

 

[RunAgroundHard]

If you have an Axiom you should be able to put the AIS into silent mode from it.

Thanks for that, I’ll check the manual. I did see a silent option somewhere on the Axiom+ when playing around with it.

 

[RunAgroundHard]

Update on set up. Only relevant if you have Apple products and an B953 unit which does not have wireless or bluetooth.

Before it is configured the Red and Yellow LED only will be lit with no flashing. The power LED and the end LED (which I think is only for the worlds models) will not be lit. If I had hair, I would pull it out, as I could not figure out why the power on LED was not illuminated.

1. In post 11 stated that the AIS was receiving and transmitting but I had not yet configured the AIS. In fact I was only receiving targets, not transmitting.
2. The unit comes with a USB Micro B x USB cable. If you have a USB C on your Apple product, you will need a cross over cable.
3. The configuration software will not run on an iPad, so you need a Mac Laptop (or Laptop). I dicked about downloading software onto an iPad from the App Store, then the web site which ultimately was pointless.
4. The laptop needs to be connected to the internet.
5. On the relevant web page on Em-trak, download proAIS2. It is one file, a Zip file. Before downloading, you need to expand the zip file on the web page and you will see the Mac option. With that open, click download.
6. Once downloaded, open up and instal as usual for apple Mac.
7. Plotter on and powered up (don't know if this is required) and AIS unit powered up, plug in the USB cable between the Mac and the AIS B953 unit.
8. In proAIS2 select "AIS Virtual Com Port"
9. You have to wait for something to happen between the AIS and unit and the internet, then the configuration fields can be edited.
10. Click on connect.
11. Enter boat details MMSI et cetera. Double Check everything is correct as the next step har writes the MMSI number to the AIS
12. Click on "Write Configuration" and wait.
13. Al the LEDS will go out and the Green Power LED will come on.
14. You can scroll through the tabs on proAIS2 and see configuration data, other vessel lists, satellite lists, data transmission log.
15. Disconnect proAIS2 using the disconnect button and pull the cable out.

Job done, check plotter, see details are all there et cetera.

I am picking up objects at 19 miles, in a marina, surrounded by hills, mountains and islands. Not bad.

 

[st599]

It won't be a crossover cable (they're a relic and only used in Ethernet now, and only then with old kit) it'll be a straight-through cable. A straight C - B micro worked well.whem I set up our emtrak.

 

[[164147]]

You don't need to power the plotter or the AIS to program it. The 5v USB supply is sufficient.

 

[RunAgroundHard]

It won't be a crossover cable (they're a relic and only used in Ethernet now, and only then with old kit) it'll be a straight-through cable. A straight C - B micro worked well.whem I set up our emtrak.

It is in my case, that’swhat I used. I don’t know why you are telling me what it won’t be when you were not there. The AIS was new, shipped from Em-trak last week, so as stated that is what they are putting in the box. In the box is a cable unsuitable for modern equipment with the USB C ports (small slot, happy to be corrected with terminology). I happened to have a hub that allowed me to use the OEM supplied cable.

Of course if a cable is available, use that.

 

[st599]

It is in my case, that’swhat I used. I don’t know why you are telling me what it won’t be when you were not there. The AIS was new, shipped from Em-trak last week, so as stated that is what they are putting in the box. In the box is a cable unsuitable for modern equipment with the USB C ports (small slot, happy to be corrected with terminology). I happened to have a hub that allowed me to use the OEM supplied cable.

Of course if a cable is available, use that.

A crossover cable switches the Tx and Rx lines between each end of the cable, they're vanishingly rare these days. It would have been a straight-through cable if it was USB.