Icom M506, five models of goodness

... written for Panbo by Ben Ellison and posted on Feb 6, 2014

Icom_IC-M506_aPanbo.jpgWhen Standard Horizon introduced its Matrix AIS/GPS radio in December, we learned from a European reader that Icom UK was showing off a VHF with just about every feature a boater might desire (with the possible exception of a built-in GPS).  As hoped for, Icom America has now revealed its version of the IC-M506 and will be showing it in Miami next week. It turns out that at least here in the states the M506 will be available in five models so you can get the features you want without paying for ones you don't...

Icom_M506_model_chart.jpgSo once approved by the FCC, the base model known as the M506 NMEA will be a conventional fixed VHF in terms of using NMEA 0183 to connect with a GPS for DSC distress calls and other functions like position sharing. But there will be kits available to add NMEA 2000 connectivity and/or a dual channel AIS receiver. The next models up include N2K with a choice of either front or rear mics, and the top two models add the AIS. Pricing is not set but may look something like $500 for the base model plus a $100 each for the two major options plus $50 for the rear mic. Icom has always been a premium brand and even the base model M506 seems to have a lot going for it.

Icom_IC-M506_mic_aPanbo.jpgFor instance, the newly designed mic is purportedly louder while still including Icom noise cancelling improvement of both incoming and outgoing audio. And the big 132×96 pixel display looks good for the nav and AIS screens as well as for using the soft key and knob interface possibly best seen on this video from London Boat Show. The M506 will also support a second station Command Mic IV, apparently including the AIS functions. I have not yet tried Icom's last call voice recording -- first seen on the M73 handheld, and extended to 2 minutes on the M506 -- but I liked the feature a lot when I've used it on other radios.
   I have not paid attention to which VHF radios support a rear mic attachment, but now that I'm trying to design new Gizmo helm panels with more of a 'glass' look, I appreciate the rear mic possibility. (I also wonder if some MFD manufacturer will come up with a big screen VHF interface something like Fusion Link, but VHF regulations may prohibit that.)

Finally, while the M506 manual is not yet available, I don't doubt this UK site's claim that the radio can easily set up direct DSC calls to an AIS target (a feature so far still missing from the Simrad RS35 and Lowrance Link 8, I think). Afterall, the M506 can apparently interface with Icom's own MA500TR AIS transponder. I wonder if a M506 N2K will display and make target calls using standard AIS data coming in via NMEA 2000. Any other questions I should ask in Miami? 



This one should get an award. It makes it easy to install AIS and it has features most dedicated AIS units do not have (DSC call set-up without manual input of an MMSI number). Hopefully it uses standard PGNs for call set-up, if that is possible yet!. I would like to see a list of the PGNs it uses. Can call set up work with with any other manufacturers' MFD? Can any other MFD display the AIS targets?

Posted by: norse at February 6, 2014 1:21 PM | Reply

Norse, my thinking is that a radio which can already display AIS and call individual targets doesn't need set-up commands from an MFD. If you see a target you want to talk to on some screen you'd just go to the target list on the M506 and call it with a couple of button commands.

I'm pretty sure that's how it will work if the M506 is the source of the AIS target info. What I don't know yet is whether a M506 without a built-in AIS receiver will still display and call AIS coming to it via NMEA 2000 or even 0183. Seems quite possible.

Remote call set up may also be possible. I think that "compatibility" with the Icom MR500TR means you can set up a DSC call on the transponder via 0183. I believe that Vesper AIS displays can do similar. I don't know if remote set up is possible via N2K, like Garmin has done with proprietary PGNs, but let's hope. And remember that the last step in making such a call is always done on the VHF itself, by law.

Posted by: Ben in reply to norse at February 6, 2014 1:56 PM | Reply

when will we get VHF with built-in AIS transponder?

Posted by: Anonymous at February 6, 2014 1:58 PM | Reply

"When will we get VHF with built-in AIS transponder?"

Possibly never. Maybe I'm too skeptical I suspect that the regulatory hurtles are extremely difficult. Plus I've never heard a VHF or AIS manufacturer even contemplate the combination. But I don't hear everything and I sure wouldn't mind being wrong.

Posted by: Ben in reply to Anonymous at February 6, 2014 2:08 PM | Reply

The eye candy I see are the separate knobs for channel, volume, and squelch. Yes !

Posted by: Dan Corcoran (b393capt) at February 6, 2014 4:02 PM | Reply

I really like Icom products, but doesn't the Lowrance/Simrad Link-8 radio do the same functions for a list price of $299 and a street price in the low 200s?

Posted by: Howard at February 6, 2014 6:52 PM | Reply

"What I don't know yet is whether a M506 without a built-in AIS receiver will still display and call AIS coming to it via NMEA 2000 or even 0183."
I have a Standard Horizon GX2000 which does not include an AIS receiver but receives and displays AIS data via NMEA0183 from my Weatherdock easy AIS TRX2. On the radio I can select an AIS target for a direct call.
To do this:
1. Press the "AIS" button
2. Press any of the softkeys to bring up the softkey menu
3. Press the "LIST" softkey. This changes the graphical display (plot) of to a list of the 10 closest targets, either with MMSI or with name, depending on whether the AIS message including the name has been received.
4. Scroll down the list using the big knob or the down key on the RAM MIC
5. On the desired target, press the "CALL" softkey (or, on the main unit, press the knob)
6. Select between "ROUTINE", "SAFETY", "URGENCY", "DISTRESS"
7. Select the working channel (You are supposed to have checked if it is available before starting this sequence. There is no way to listen into each of these channels while selecting them here. Why not?)
8. Press "YES" on the final "Transmit?" question

While I am happy to have this feature, there are a number of drawbacks:
- You are limited to the list of the 10 closest targets. There is no way to bring up the next 10 targets. However, pretty much the only reason why I would want to call an otherwise unknown AIS target is to ask them if they indeed intend to run me down. This means that my target is very likely in the list of 10. If I'm calling a friend, I would have the friend in my directory.
- I don't think that step 6. makes much sense. I believe that by definition, a safety, urgency or distress call goes out to all stations.
- It's a fairly long list of key presses, limiting it's usefulness somewhat. However, except for step 6 there is not much SH could do to make the process shorter. The only real difference would be to initiate the process on the chart plotter by selecting a target displayed there. But you would still need to select the working channel (which you are supposed to have checked for traffic before beginning selection on the chart plotter).
- in 3 seasons of sailing and about 3500 miles I have used it only once. The reason being that in all cases that I have called a big ship bearing down on me in the traditional way on channel 16, they responded immediately.
Generally, I consider this feature less important than I used to.

"I don't know if remote set up is possible via N2K, like Garmin has done with proprietary PGNs, but let's hope."
There is still no PGN defined for setup of a DSC call. So it would have to be done via proprietary PGNs and since Icom does not manufacture chartplotters, I guess that pretty much rules them out to support such a function.

Posted by: Henning at February 6, 2014 7:25 PM | Reply

I called Icom last week to ask some questions about this radio and the salesperson I spoke with did not have information on it. I mentioned that there were already magazine ads out with the disclaimer that the FCC had not approved the radio and he didn't even know that.

I really like Icom devices and had planned to install two units as soon as they are available. From the UK press info, I am disappointed that Icom has not caught up with Simrad's wireless handset. The Simrad RS35 does not have the fog signals that I was looking for. As much as I wanted two similar units, I probably will be buying on Icom and one Simrad.

Ben - have you heard of any manufacturers looking into a Bluetooth headset option? When we are running, I would like to have a headset that syncs with my cell phone and VHF. We often have folks on board talking, music playing, etc and the VHF is not always easy to hear, so the headset would help a lot.

A Fusion type interface on the MFD or touch screen would make DSC calling and channel selection.

Posted by: HenryD at February 6, 2014 9:31 PM | Reply

I know, I was just hoping out loud.

So the additional questions to ask Icom or any other VHF/AIS rep. are
* Is there some regulatory thing that discourages VHF and AIS Class B together in one box (and sharing the same antenna)? and
* How is that N2K standard for call set up coming?

It's nice to have the high-tech equipment available; it would be even nicer if it were simple enough to install and simple enough to use that more people would buy it and use it.

Posted by: norse at February 7, 2014 12:02 AM | Reply

I saw the Icom at the London Boat Show and it's a great bit of kit but of course lacks the transponder capability.

Like Henning has tried with an AIS receiver and GX2000, this could also be a solution for people wanting to integrate a transponder with a VHF solution. At Digital Yacht we tried this combination with a Standard GX2000 back in October and it works well. There's a link here on our blog which shows the connections http://www.digitalyacht.net/2013/10/11/ait2000-gx2000e-a-great-combination/

Posted by: Nick Heyes at February 7, 2014 6:04 AM | Reply

Hallelujah! Icom. Welcome to NMEA 2000 World. You had me worried for awhile.

I have the very old Garmin VHF200, one of the first ever in distribution and a problem product aboard my boat from day one, (three times back to Garmin for service). Garmin should be looking at a next generation VHF - it’s about time for this now that they have ironed out the bugs. Their next generation VHF should be worth a look - whenever that happens to be.

In the mean time, I’ll be coming home Icom.

Posted by: Richard C at February 7, 2014 8:44 AM | Reply

Will it be a drop-in replacement for the 504? Is the user interface any better than the present pushing multiple buttons for functions? I still have to get the manual out just to turn on and adjust the fog horn.

Posted by: Mike B at February 7, 2014 9:36 AM | Reply

"When will we get VHF with built-in AIS transponder?"

As Ben wrote, I would not expect to see an integrated transponder any time soon. Sharing a receiver antenna is easy, even with a four-way split (voice channel, DSC, AIS1 and AIS2) which can be done after the first RF amplifier stages. With DSPs, you can down-convert the marine band to something that feeds an ADC, then have software filter and receive 3, 4 or more signals at once. The additional cost is minimal.

But an AIS transponder needs to transmit periodically, and fairly often. That can't be shared with a receiving antenna, so the receivers (all four) would have to shut down every time the transponder sends. That would chop up incoming voice conversations, or the transponder would have to inhibit its transmissions whenever the squelch opened, which would not meet its reporting requirements.

It could be done with separate antennas, which would have to be mounted some distance apart, and would likely lead to support issues when people inevitably installed them too close together. It would also be extremely challenging to have a 10w transmitter operating in the same housing as several receivers on nearby or even adjacent frequencies. It's (barely) technically possible, but there isn't nearly as much synergy/cost-saving as there is integrating the AIS receivers, or GPS/AIS/DSC/VHF.

Personally, I'm a longtime Icom fan, both amateur and marine, although Redline is currently equipped with a SH GX2150 AIS/VHF. It works well, and is on the air as we speak, as Marinetraffic station 1781).

s/y Redline

Posted by: Redline at February 7, 2014 9:52 AM | Reply

Redline, it's very cool that you're running a volunteer Marine Traffic AIS station off your boat with an GX2150 and WiFi. Even cooler that you score 99.9% uptime over the last three months:


How about a Panbo guest entry about how you did it? I just need text, photos, and hopefully links to products used. An excellent not-available-in-any-store Panbo hat is one reward, maybe more MT volunteers another.

Incidentally there are several Class B AIS Transponders with built-in VHF splitters as well as standalone AIS/VHF splitters. I've tested several with good results.

Posted by: Ben in reply to Redline at February 7, 2014 10:55 AM | Reply

Mike, I have some Icom literature which says that the M506 is "almost identical size as the M504".

But the user interface is the same as the "M424, M92D, M400BB, and Command Mic IV." I think that this is much changed and purportedly friendly interface that Icom is rolling out on all new radios, including handhelds and comman mics. Check that London Boat Show video in the entry for a peek, or download a manual for the M424.

Posted by: Ben in reply to Mike B at February 7, 2014 11:03 AM | Reply

Ben, I'd be happy to. Presently the boat is on shore (and according to the instruments, which are also live and on the internet, it's -8C in the cabin, but next visit I'll try get some pics and draw up a (long overdue) diagram of how it's all connected. Fair warning: this is not your typical marine electronics installation. ;-)

I've been hoping to get 100% uptime, but a power failure got in the way (shutting down the club's WiFi, even though Redline stayed up). My uptime wasn't much worse late in the summer, even when the "station" went sailing periodically.

p.s. loyal Panbo reader, great admirer of your work.

Posted by: Redline in reply to Ben at February 7, 2014 11:21 AM | Reply

Thanks, Nick. I think it's fabulous when a company publishes detailed information about how their product integrates with another company's, right down to the NMEA 0183 wire colors. Standard Horizon is notably good about this as seen in their GX2150 support files: http://goo.gl/jLkzPC

HenryD, SH also has Bluetooth VHF mics, or used to. Now I only see the option listed with GX5500: http://goo.gl/sVH79u

There may also be an SH handheld VHF that works with the BTK2 Bluetooth Kit. I tried one once and it worked pretty well, but the fact that newer SH radios don't seem to support it suggests that there wasn't much demand. I'll ask about it in Miami.

Posted by: Ben in reply to Nick Heyes at February 7, 2014 12:10 PM | Reply

Redline says:
> But an AIS transponder needs to transmit periodically, and fairly often. That can't be shared with a receiving antenna,

AIS transponders CAN (and DO) share the VHF antenna with a VHF if you use a (transponder) splitter. ALL vendors of AIS class B transponders sell such a device!

The AIS transmission is once every 30s for a few milliseconds, so it does not interfere significantly with any voice reception or transmission.

All available solutions right now use a separate splitter box. I guess that they prioritise voice transmissions over AIS, as otherwise they'd have to divert 25 W of power. One advantage of a combined solution would be that it could mix in the AIS transmission on ch 70 even when sending voice. Nobody would miss a few ms in a normal voice transmission.

Posted by: Kees in reply to Redline at February 7, 2014 5:49 PM | Reply

Still no built in GPS.....

Posted by: Glenn Dunstan at February 7, 2014 6:26 PM | Reply

I've been waiting for a VHF with AIS transponder also.

Posted by: Rob at February 7, 2014 10:20 PM | Reply

... Can't imagine why s/y Redline is currently "on shore"...


Brrr. Good job with the MarineTraffic Station. Wish we had a few more in sparsely populated areas where they're really needed!

Posted by: Grant at February 8, 2014 10:47 AM | Reply

A huge yawn. AIS receivers for boats were hot news back in 2005. Who cares about a receive-only unit? The market is all about transponders now, receivers are mainly sold for land-based networks. Anyway the display is too small to be of practical use for plotting AIS targets.

Kees writes "All available solutions right now use a separate splitter box". Not true, the True Heading transponders have had integrated antenna for many years, both the current model CTRX Graphene+ as well as the previous CTRX Carbon+.


Posted by: Marcus AAkesson at February 8, 2014 6:59 PM | Reply

If you are in for a transponder who can do it all , easy ais made a leatherman, nmea0183, n2k , internal gps antenna , internal vhf splitter, Wifi, sd card recorder,and many more options. Also a fm and DVBT out last works pretty good in the Netherlands if you use low loss coax like aircell7.I am expecting one later this month so can't tell how well it works yet.


Posted by: tcy at February 9, 2014 4:19 AM | Reply

Hi Marcus,

Yes you are right there are AIS transponders with the splitter built in, I guess I meant that there are no VHFs with a splitter built in. I can't really explain why I wrote it in that manner, though.

Even so, the True heading models with a splitter built in are built in at customer level but not at hardware level. See the last part of Ben's post http://www.panbo.com/archives/2013/07/seapilot_true_heading_ais_in_sweden_2.html where you can see that the Graphene contains a SRT Cobalt Class B module and a SRT Trident 2 antenna splitter module.

It would be interesting to see the inside of the Easy AIS from Weatherdock, to see how they do this.

Posted by: Kees in reply to Marcus AAkesson at February 9, 2014 9:36 AM | Reply

Hi Marcus,

I'll add some other reasons that VHF's with AIS receivers are of interest.

* While I agree that the displays are too small for very effective AIS collision avoidance, the output can of course be sent to bigger screens, especially easy with NMEA 2000.

* Some users like them as a backup to a full transponder and/or a way to keep an eye on AIS traffic when their boat is anchored or tied up with the transponder and MFDs turned off.

* AIS aware VHF radios should be able to place direct DSC calls to AIS targets without having to key in an MMSI number. Unfortunately this is not yet as great a feature as it sounds because many vessels, even ships, aren't used to receiving direct DSC calls -- or don't have the same MMSI programmed into radio and trasponder, like they should -- but the more boats that have the feature, the more it will get used, I think.

* Finally, US recreational boats, and even light commercial boats, have not yet taken to AIS as much as in Europe and other parts of the world. I've seen plenty of million dollar boats with no AIS or maybe just a receiver. But it's slowly changing.

Posted by: Ben in reply to Marcus AAkesson at February 9, 2014 9:51 AM | Reply

As to European AIS usage -- I gave a lecture to my sailing club yesterday, and out of curiosity I asked who had AIS fitted. About 15% didn't have anything at all, 40% had a receiver and about 45% had a transponder fitted.

Posted by: Kees at February 9, 2014 10:00 AM | Reply

"* AIS aware VHF radios should be able to place direct DSC calls to AIS targets without having to key in an MMSI number. Unfortunately this is not yet as great a feature as it sounds because many vessels, even ships, aren't used to receiving direct DSC calls -- or don't have the same MMSI programmed into radio and trasponder, like they should -- but the more boats that have the feature, the more it will get used, I think."

Ben, you are of course correct. Garmin, are you paying attention?

Posted by: Jeremy at February 9, 2014 11:05 AM | Reply

Kees how are the (easy) doing what?, the splitting of the VHF signal or the DVBT?.

I try to recommend customers to take a transceiver instead of a receiver. most of the receivers I mounted are replaced by a transceiver.

But, yes in Europe and also in the Netherlands there are a lot of boats with AIS transponders. Some of the MFD's mostly older MFD's can't deal with all the information they receive from the AIS and black out. When the summer is here again check marine traffic on a Sunday afternoon and zoom in on the IJsselmeer looks like you can walk from one side to the other. When you own a Simrad MFD with their huge AIS targets you can't see the MAP anymore just triangles.
A problem no don't think so just turn of the alarm.

Posted by: tcy at February 9, 2014 11:12 AM | Reply

Last fall in the English Channel crossing from Ijmuiden to Ramsgate we were closing in on the traffic separation scheme under engine. Shortly before I was going to change course sharply to cross the traffic lane at a right angle, we fouled the propeller with a largish fishing net. We were unable to make more than half a knot of headway. There was no wind that would have allowed us to sail in any direction. The tide that had just turned was slowly setting us into the traffic lane. Daylight was just breaking and visibility was not good.
On the AIS display I could see a string of fast moving cargo ships come up the traffic lane and I could see the first one up changing course slightly to avoid us.
This is the kind of situation that would certainly have made me buy a transponder at the next possible opportunity had I not already had one.
On our way to the Canaries I have had several more experiences where big ships changed course for us so that I could hardly see on the horizon. Clearly they could not see us and were making the course change based on their AIS display.
Since their class A AIS transponders transmit at 12W vs. our class B at 4W, I will see them at a much greater distance than they can see me but still, based on at what distance I could see them change course for us, I estimate that they can see us at 12nm distance.
If I had to chose between a device that would only transmit, not receive, and one that only receives, I would get the transmitter.

Yet we have met numerous other boats on the way that believe a receiver is all they need. I don't know why and I am not sure that I am getting through to them with my arguments. Some say that their steel boat makes a good radar target. I think there is a big difference in having to diligently look out for a small radar target vs. having to cancel an AIS collision alarm (and probably having to make an entry in the logbook about it).

I am reminded of an old joke: Someone says to God "please, God, let me win the lottery". To which God responds "please help me and at least buy a ticket".

Posted by: Henning at February 9, 2014 11:27 AM | Reply

Henning, I feel your frustration. The "receive-only" crowd needs to get a clue. How about this argument - If EVERYONE only had AIS receivers, what would our displays look like? A blank screen. Collision avoidance only works if ALL participate. If you think you only need a receiver to avoid the "big guys", I guess you're OK getting broadsided by 30 footer going 25 knots in the fog - with HIS "receive-only" AIS as silent as yours. And your absolutely right - radar is active and requires trained, diligent human interaction- in other words, very prone to failure. AIS is passive and infinitely more reliable. For those NSA objectors who think they're being stealthy by choosing receive-only units, wake up - you can be tracked a hundred other ways you haven't even thought of.
Or, maybe they're just cheap...

Posted by: Grant at February 9, 2014 11:54 AM | Reply

If you think you only need a receiver to avoid the "big guys", I guess you're OK getting broadsided by 30 footer going 25 knots in the fog

Has there been any word recently on when the must-have/must-use regulations are going to be tightened up?

Posted by: norse at February 9, 2014 4:12 PM | Reply

Marcus wrote

Anyway the display is too small to be of practical use for plotting AIS targets.

Actually, I've found the display on even the RAM3 remote microphone to be very usable. As it shows only AIS targets, in some ways they're easier to pick out than those amid all the other chart detail on the MFD. I sometimes check bearing/distance on the smaller display to assist in locating the icon on the chartplotter (somehow this sounds much worse than it is).

As for receiver vs transponder, where I sail the "big guys" are pretty much draft-restricted to the Seaway channels, so it's entirely up to me to stay out of their way. AIS helps. Were I spending significant time downstream from Montreal, I'd be looking at a transceiver, and I did spot far more 30-footers transmitting AIS while transiting those parts.

And IMHO, anyone doing "25 knots in the fog" had better have more than just AIS anyway - there are lots of pretty solid objects out there (many floating right at the edge of the channel) that aren't on AIS.

One day, but in the meantime, the VHF/AIS combo represents a lot of utility for the cost and minimal installation constraints.

Posted by: Redline at February 9, 2014 10:33 PM | Reply


My example was simply to illustrate that small boats can create just as serious a safety hazard as large ones, given the wrong circumstances - not to suggest such activity is necessarily common or endorsed. This is in response to the argument that receive-only AIS is sufficient for smaller vessels.
EVERYONE needs to get on board with two-way AIS capability if the anti-collision benefits are to be realized.
Apparently some folks didn't get that point.

Posted by: Grant in reply to Redline at February 10, 2014 12:48 AM | Reply

re: combined AIS and VHF

I suggested this at an standards meeting many, many years ago and was promptly shot down by at least two of the regulatory representatives there.

That doesn't mean that it can't (or won't) happen, it's just that regulation seems to stifling innovation (again?).

D, from a very damp UK.

Posted by: Anonymous in reply to Ben at February 10, 2014 9:11 AM | Reply

I'm a newbie to the world of AIS, but I've been messing with VHF and RF systems for a long time, so I think I can comment on some of the potential issues here.
With one antenna servicing two transceivers, the biggest issue is what to do when both want to transmit. With the external splitters, it's my understanding that they default to the VHF comms side, and simply terminate (dummy load) the AIS port when the comm TX is active. The comm side receiver is simlarly muted (by being disconnected from the antenna) when the AIS transponder transmits, but since this is only 26ms or so (plus switching time), this isn't a real impediment.
Connecting two active transmitters simultaneously is not easy, however, as the potential for mixing and radiating the product of the two carriers is high, with resulting interference potential to other services (and such "spurious outputs" are legally limited).
I wonder if the lack of integrated AIS transponders (as opposed to receive-only) is due to this issue - which would interrupt the legally determined transmitting schedule? Running many receivers off the same antenna is easy - it's the transmitters that are difficult, even at only 2 watts.
You could, of course, construct a unit with two antenna ports, but that would seem to negate a lot of the incentive..:-) You could also build in the requisite filtering, but it wouldn't fit in any reasonable-size box (reasonable for recreational vessels, anyway)
I also understand that the AIS transponder needs it's own GPS, though this wouldn't seem to be difficult to address.

Posted by: Hartley at February 11, 2014 2:14 PM | Reply

Icom has always done an excellent job with their VHF radios. However, they made a big mistake when they moved away from the size of the M80, M100, M120, M125, M127. They sold a ton of these models all of the same dimensional size. Retrofitting can be a difficult. Please Icom, give us a Model 606 in the size form of the early models...

Posted by: Kevin Savord at February 13, 2014 1:13 PM | Reply

The 506 was released to dealers yesterday. It will be the radio we spec in systems that have a n2k GPS (and what system doesn't these days).

Posted by: emsusa at May 1, 2014 2:55 AM | Reply

I just unboxed the new Icom M506, N2K, front mic, black. (without AIS) Here’s my first impression.

The first thing I noticed was the absence of a NMEA 2000 drop cable. I guess I’ll have to go out and buy one before I can complete the installation and try the radio with a proper data feed. Up to now, every marine electronics device l’ve purchased has included an N2K drop cable. My first impression right off, “That was Cheap, Icom”.

As I checked out the radio I noticed two “very small” white plugs on the end of two bundles of conductors. These wires coming out of the back of the M506 and ending with the white plugs are very short about 5 inches. What puzzled me was no matching connector was included. So, what was I to do with these very short but neat wire bundles? I own nothing that could possible accept these plugs. The M506 manual on page 102 fully explains what the two white plugs on the end of very short wires are for.

Just cut them off! Yup, that’s what it says. Let me continue to paraphrase how I interpreted the manual -

“cut off the white plugs, throw them away after you just paid a lot of money for this whiz-bang, latest, greatest VHF radio and proceed to make your own non-waterproof, failure prone splice from the 22 AWG Icom wire to whatever big wire you use for NMEA 0183, Hailer and External Speaker and good luck.”

Do I sound annoyed?

Icom, You have to be kidding! No customer wants to buy something and start cutting off perfectly nice plugs as part of the official installation instructions. Can’t you give me a long enough cable with a waterproof connector that will survive a salty environment? I need a cable long enough to make my connection in a safe, protected location. Not five inches from the back of the radio. Not all M506 radios are going to be installed flush mount in a dry location.

At least I can say Icom is honest. The manual admits that the M506 is IPX8 waterproof, “except” for the power and data cables that you have to cut the plugs off in order to install. (page vi).

The M506 better be one hell of a radio when powered up for me to keep this and not send it back. I have been buying marine electronics for a few decades and in my opinion, this unboxing, first impression is not in tune with Icom’s reputation for excellence.

Posted by: Richard C at May 13, 2014 2:16 PM | Reply

M506 N2K, MA500-TR AIS Transponder and NMEA2000.

Hi guys, I currently have a M505 and the MA500-TR AIS transponder. The MA500-TR sends data to my chartplotter and other devices through NMEA0183. I could see myself changing the VHF to the 506 N2K if it allows me to get rid of the whole NMEA0183 on my boat (leaving me with *only* 3 nets: N2K, Nexus and ethernet...) if by chance the 506 N2K is able to relay the data from the MA5000-TR onto the N2K network without the need for the 0183 output of the AIS transponder to be separately connected.

Does anyone know if the M506 N2K can indeed relay / send data it receives from the AIS transponder onto the N2K network?

Thanks in advance

Posted by: Nononsense at June 9, 2014 10:37 PM | Reply

I just reviewed the manual for the IC-M506 (http://www.icomamerica.com/en/downloads/DownloadDetails.aspx?Document=666) and it appears that the connection to the MA-500TR is only via the NMEA 0183 port (see page 102 "Connect to the MA-500TR).

I saw no mention of whether it would re-send this data out the NMEA 2000 interface.

Posted by: Eric at October 8, 2014 3:30 PM | Reply

Eric, thanks,

I did read the manual as well and did not see mention of what I was looking for, which does not leave me very optimistic.

On the other hand, you would think that if you were designing a new VHF transceiver with NMEA2000 instead of 0183, and if this VHF is designed to work with the MA-500TR which itself has 0183, then it would make sense to have the VHF translate the data from the AIS transceiver to NMEA2000, otherwise you are better off with a 504 / 505 VHF as I have right now (only one 0183 data connection instead of one 0183 + one 2000).

I guess I need to get hold of an ICom tech to get to the bottom of this.

Posted by: Nononsense in reply to Eric at October 9, 2014 11:41 PM | Reply

I was also interested in being able to utilize an existing N2K AIS signal off of my system to provide AIS target information to the N2K/non-AIS version of the radio, the IC-M506 PLUS.

Compatibility with 3rd party AIS sources isn't in the advertised feature list, but ICOM's tech support quickly pointed to N2K configuration pages 89 and 90 of the manual, which detail selection of GPS and AIS N2K sources along with a list of GPS and AIS related PGNs that can be received over N2K. The gentleman I spoke with was very helpful and efficient, but listing general compatibility in the feature list would have saved the trouble of a call.

The instruction manual information on N2K source selection and PGNs reassured me enough that I ordered up the plus version of the radio, which I was able to install today.

The installation was completely plug and play. The radio automatically received available GPS and AIS sources with only an N2K network connection.

My AIS source is a Si-tex Metadata Class B AIS transceiver. There was an apparent AIS source configuration menu anomaly in that the Si-tex transceiver was not listed as a source in the menu item, where only a default "All" option was displayed. This would presumably only be a problem if wanting to select from multiple sources.

The various N2K GPS sources on my network were actually displayed in the GPS source configuration menu item, with individual sources selectable along with the default "All" option.

I'm very impressed with this radio so far. It was an easy drop in replacement for the failed Garmin VHF-200 that it replaced. In addition to the added AIS features and plug and play operation, this radio is a big step up in display quality, the ease of use of the user interface, and also welcome usability features like remembering and returning to the last operating state when power cycled.

Posted by: Karl at October 19, 2014 3:23 AM | Reply

I have always been a big ICOM fan. Our SSB, Ham, VHF fixed, VHF portable and now AIS are all ICOM. Last year I was thrilled when the MA-500TR came out. This year I dutifully replaced my 504 VHF (firmware too old) with a 506 to access the full inter-functionality. Of course I checked with ICOM reps to make sure I was buying the correct 506 model... the NMEA2000 one.

Install of both units was plug and play (although the jig saw had to come out to make the 504 hole a tiny bit larger for the 506). DSC works great... but the 500 DOES NOT transfer its AIS data to the 506. The nice AIS target displays on the 506 and remote remain empty. After numerous emails to ICOM tech support (some giving me incorrect information) I now know that I need to convert the 0183 data out of the 500 into NMEA 2000 data for the 506 in order to see any AIS data on the VHF.
Having AIS data in the 506 is really only important if you have the 500 at the nav station below... and the 506 remote microphone at the helm... as we do.
I learn so much from Panbo... hope this helps someone sort through this ICOM maze faster than it took me.

AIS... I will never sail without you. ICOM... I love you... but I love you less now.

Posted by: James Fine at January 15, 2015 11:10 AM | Reply

James, that is probably the nicest customer complaint comment I've ever read, and I hope it's effective. In fact, I intend to forward it to my Icom contact.

But I am a little confused. The MA-500TR does not have NMEA 2000 output, but does have 3 NMEA 0183 ports, one of which outputs AIS VDO and VDM messages, another one of which outputs the DSC message:


So I'm assuming you got the M506 with N2K but not an AIS receiver. Do you have a chart plotter system with NMEA 2000 network? When you say DSC works great, do you mean you see it on a plotter or where? Hopefully there's a way to work this out, though it may take an 0183-to-2000 gateway.

Posted by: Ben in reply to James Fine at January 15, 2015 11:59 AM | Reply

Thanks Ben. I am currently able to select a target on the AIS and make a DSC call with the push of a button. VERY cool... especially useful when a very large ship... travelling at 3 times my speed is on a collision course and only a few miles away.

Calling a ship on 16... even by their name does not usually solicit a response anywhere near as quickly or reliably.

I currently have to do this at the nav station. I am NOT yet able to do that at the helm... which is the issue. I have already ordered a 0183-2000 gateway and will install it next week. Should solve the problem... but IMHO ICOM should have made these two units play together without 3rd party converters and so much confusion.

Posted by: James Fine at January 15, 2015 4:58 PM | Reply

James, Ben, thanks for the feedback. A few weeks ago an Icom US tech support person explained the same to me -- I would need to convert the 0183 data from the AIS unit to NMEA 2000 data separately. This could mean that the connection between the AIS unit and the VHF only relates to making DSC calls to AIS targets (Ben: I suppose this is what James means), even for those new 506 VHF with AIS capability.

Out of this I conclude that, for me, it would make more sense to upgrade my VHF (504, same as you) at the same time as the MA-500TR -- if ICOM have upgraded their VHFs to NMEA 2000, it would make a lot of sense for them to do the same for their AIS unit shortly thereafter. I do like the MA-500TR AIS a lot, It gives me the information I need, and only the information I need from an AIS unit. But until they upgrade it, I continue to live with 4 networks on my boat: NMEA 2000, NMEA 0183, Nexus and ethernet.

Posted by: Nononsense at January 15, 2015 6:53 PM | Reply

Thanks for your comments Nononsense. Thought I was the only one with this issue out there.


I built a NMEA 2000 backbone and purchased an Actisense NMEA 0183 to 2000 converter... http://www.actisense.ca/products/ngw-1-nmea-2000-gateway ... and it works. I now have the functionality advertised. The 506 and its remote Command Mic IV have full access to the AIS data and can make DSC calls to AIS targets with the push of a button.

Would have been cheaper to buy the 506 with the AIS receiver... But it does not make sense to me to have two AIS receivers. (Reminds me of a Chinese proverb... man with 2 watches never knows what time it is).

Hope this is of assistance to others (and to ICOM Engineering and Marketing)

Posted by: James Fine at January 25, 2015 8:34 AM | Reply

Bought an Icom AIS 506euro thinking it would receive and display AIS targets on the target screen (as shown on the outside of the box and internet adverts). Got home installed radio in the boat only to find the target screen showed no targets. I subsequently found the radio must be connected to an external GPS/plotter for the target screen to be populated with shipping. No mention of this requirement is made anywhere in sales literature (or if it is it's not immediately clear) or on the outside of the box.

Why, Icom, did you not include a built in GPS it would have been so easy to do? Standard Horizon included GPS in their AIS VHF radio (which sells for less). Having GPS built in would also have made the radio a complete stand-alone unit without the need to connect to a plotter/GPS for the AIS to fully function.

I explained my disappointment to Icom at the lack of a built in GPS and the fact the radio had to be connected to a plotter. Also that such required connection is not made clear to a potential purchaser. Basically I received a blunt reply (reading between the lines) that I should have looked closer. Not the reply I expected.

My guess is it won't be long before a Mk2 GPS version comes out. All I can say is well done Standard Horizon.

On another tack, the noise blanker is not very effective. It simply seems to reduce treble in the audio. More worryingly it's use also introduces a weird warbling sound which correspondingly increases with the level of blanking. The warbling distorts received audio to a level which is annoying to listen to. So I found it best to turn off the blanker because of the above shortcomings.

"try's hard could do better" spring to mind.

Kent England

Posted by: Ron at April 28, 2015 5:00 PM | Reply

Ron, I don't have a a '506, but I am willing to bet that if you manually enter your Lat/Long into your radio* then you will see AIS targets. It's not that the radio is not receiving them, but that without knowing where it is, it doesn't know where to locate the center of the plot.

I had a similar issue running NavMonPC (great little program by the way) on my AIS-only feed without giving it the ship's GPS feed first; it placed the plot at Lat 0 Long 0, and none of the AIS reports being received were anywhere close to that.

* I've entered Lat / Lon on a DSC radio manually once, for testing, which made hooking it up to a GPS source vastly more preferable. Talk about tedious. And one is supposed to update the position at least every 4 hours, which is beyond tedious, not to mention error-prone.

Much of the usefulness of DSC is lost without an up-to-date position, regardless of AIS.

Posted by: Redline at April 28, 2015 8:15 PM | Reply

Sorry, Ron, but I'm going to be a lot less polite than Redline. You have no grounds for criticizing ICOM over the lack of GPS in their M506 radio.

You've demonstrated a frightening ignorance about safety communications here, and you probably should not be installing a VHF radio yourself. Plus I have to wonder if you're prepared to send a DSC Distress message if necessary, or if you'll understand what's happening when you receive one.

All new fixed VHF radios have required a GPS connection to do DSC Distress calls for well over a decade. It's great that Standard Horizon has recently figured out how to integrate GPS receivers into some of their VHF and VHF/AIS radios, but it is not "easy" technically and the vast majority of current VHF radios do not include GPS.

What SH has not done yet, but ICOM has with the 506, is to provide NMEA 2000 networking in addition to normal NMEA 0183 receive and transmit ports. N2K makes GPS input and AIS target output really easy, if the installer knows what they're doing.

Ron, here's a start to the research any DIY VHF installer should do:


I suggest that you owe ICOM an apology.

Posted by: Ben in reply to Ron at April 29, 2015 8:35 AM | Reply

I agree, the biggest selling point is the NMEA2000. I am able to use my externally mounted NMEA2000 networked GPS sources.

Much easier to input NMEA2000 GPS and output NMEA2000 AIS. AIS displayed on radio is really not useful, more of gimmick to me.

When I asked SH about NMEA2000, they said never. That will change, but having the AIS targets show up on my plotter is much more important.

Posted by: Howard at April 29, 2015 11:37 AM | Reply

Hi, recently installed the new Icom with n2k and AIS, just to found the 506 was reading my own AIS signal. Indeed EUREKA has a True Heading transponder, although the 506 has EUREKA's MMSI, the AIS alarm of the 506 was showing EUREKA as a danger...

Contacted Icom technical service to learn there is a new firmware. 1.0004 that allows up to 10 MMSI to be encoded and so ignored by the 506.

The upgrade can not be done online, so the radio needs to be sent to Icom for the upgrade.

So if any is facing the same problem, now you know there is a new firmware that solves the problem

Regards, from the Mediterranean!


Posted by: Pol Vallina at November 25, 2015 9:22 AM | Reply

Hi Pol,

Firmware updates can also be done in the field by dealers with the correct firmware loader and cable. Our experience (for anyone trying), you may have to run the update several times before the 506 takes it fully, the comms seem to fail between the radio and PC. Keep trying, it eventually takes it.

Posted by: emsusa at November 25, 2015 9:36 AM | Reply


Icom was extremely helpful and send today a courier to pickup the radios, similar problem with a nearby boat.
The will return to us free of transport charges in a couple of days. Hope everything will work fine.

Posted by: Pol Vallina in reply to emsusa at November 25, 2015 2:51 PM | Reply


I being using the 506 for a while, but only recently I have stated the following; when activating the DW, everything works fine while rx, but once I answer to a call on the working chanel, the DW automatically turns off. This is quite anoying as each time after finishing the communication I have to push again the DW key.

Firmware is V1.004, is this only happening on my unit, or is what I will consider a bug? I do no recall any VHF that once the DW is activated, it disconnects each time tx is done.

Might I have done a wrong setting? Thanks in advance for any comment,



Posted by: Pol Vallina at July 3, 2016 11:38 PM | Reply

Ben Hi,
Looking at all of the above comments looks like I am not the only one frustrated with this particular radio.

I only have a very small yacht so did not want to go down the NMEA 2000 route involving very expensive drop cables etc. So I made up an NMEA 0183 cable to interface with my Garmin 557XS plotter. Both radio and plotter and optional remote mike now display AIS targets beautifully. Sadly after the first time out condensation formed on the inside of the mike screen when in warm sunlight. I tried various times/ways to dry it out but without success. (Thank you Reline)
Kind Regards
ps Ben, I passed a City & Guilds "radio communications" exam in 1980 and was issued with a G6 amateur radio call sign and have owned Icom equipment since the 1970's.

Posted by: Ron Stuart-Moonlight at August 13, 2016 1:24 PM | Reply

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