VHF radio recalls, not to worry?

... written for Panbo by Ben Ellison and posted on Jan 13, 2013
nearly_empty_VHF_shelves_at_West_Marine cPanbo.jpg

A Panbo reader sent this recent photo of empty VHF shelves at a West Marine in Florida along with a store manager's report that Standard Horizon and Uniden had called in their inventory for a software upgrade needed to meet an FCC regulation. Yikes? The reader wondered if this had something to do with Class D VHF mandates and worried about same model radios that had already been bought and installed. My head hurts from the research involved but I'm pretty sure that the answer is "no worries"...

What I think is going on is largely bureaucratic and has little to do with the features and performance you actually get from your radio. On March 25, 2011, it became illegal in the U.S.A. to manufacture, import, sell or install fixed VHF radios built to RTCM Standard SC-101. The ruling was U.S. specific because no other country had permitted SC-101, which made DSC VHF sets less expensive to build because the radio could just poll DSC channel 70 frequently instead of having a separate dedicated receiver to monitor it. This was a fairly big deal as SC-101 radios can miss DSC calls when they're in use, though in fact most manufacturers had already gone to full Class D (dual receiver) sets well before March, 2011.
  Now we go into the weeds. What the original FCC ruling actually said was that all U.S. VHF sets must be built to the international specification ITU-R M.493-11 (which only permits Class D at minimum) but what it should have cited was the newer ITU-R M.493-13 Recommendation. So in December, 2011, the FCC issued a public notice that is sort of an apology but which also set a deadline of January 1, 2013, for full compliance with 493-13. (I challenge you to read that bit of gobbledygook without sighing.)  So what is the difference between 493-11 and 493-13?  Standard Horizon's Jason Kennedy told me that while he isn't an engineer he thinks that 13 tries to make DSC easier to use and is one of the reasons that many companies like his have gone to soft key radio interfaces. (The ITU lets you download a complete 493-13 PDF here; see if you can figure out what it means in terms of actual radio design, but keep headache medicine handy ;-).
  Kennedy also sent me FCC certificates indicating that all current Standard Horizon radios meet the ITU 493-13 specification (it's a "recommendation" that's used as a specification). But what ruined his holidays was learning that the actual certified software had not been going into production radios as early as he thought; hence the nation-wide inventory recall "to be on the safe side." When I asked if a user could detect a difference between an updated radio and an older one, Kennedy said he very much doubted it. Standard Horizon and other manufacturers have been trying to build to the 493-13 spec for some time; the recall was just a matter of the exact FCC certified software. Apparently Uniden had a similar issue and in my research I discovered that Raymarine tried to get a 493-13 waiver for the RAY240 but the FCC denied it. I don't know why that radio couldn't be brought up to the -13 spec but apparently Ray has a new model in the works.
  Another item the FCC "clarified" in that December 2011 Notice was that both ITU 493-11 and -13 require a VHF radio to have a DSC Test routine. Apparently some manufacturers had missed that nice feature in the spec (you try reading it!), but I know that Standard Horizon has had it for a while, or at least that I tried it successfully on a Matrix AIS GX2100 back in August, 2011. I appreciate the efforts of regulators to make DSC VHF easier to use, but will its use ever become common? During my research, I came across this PROPOSALS FOR A PRELIMINARY DRAFT REVISION OF RECOMMENDATION ITU-R M.493-13 (PDF), which suggests a standard menu structure among other things. Would that make a difference? I pretty well understand all the DSC options seen in that menu below and can find them on various sets from Icom, SH, Garmin, Sailor, etc. but I rarely use them because nobody else does.
  In fact, I used regular VHF a fair amount during my trip from Maine to South Carolina -- and was glad that the radios have GPS connections and are ready to output DSC Distress calls if needed -- but I never received a DSC call of any kind and didn't make any myself. Is it different in your area? Also, please speak up if you know anything more about the FCC 493-13 ruling, especially if it makes an actual difference to boaters.



Hello Ben,

Re the revision of the DSC spec. The ITU committee responsible meets in Geneva in May. I am a member.

The aim of the revision will be to make DSC as easy to use as possible. Unnecessary stuff will be removed (hopefully!).

There have been 13 revisions of the spec...we want to make -14 the last for some time, so we have to get it right.

Industry, regulators, educators and users need a stable specification.

Glenn Dunstan

Posted by: Glenn Dunstan at January 14, 2013 8:23 AM | Reply

Strange that FCC imposes new standards that are still in the process of correction and acceptance by, amongst others, IMO and the rest of The World!

The chairman of ITU WP5B does not forecast stability in M493-13 until March 2013 and that date has slipped 6 months already!

What happens if M493 has material changes during this revision?

Another recall???

Posted by: Dave Walsh at January 14, 2013 9:50 AM | Reply

I don't understand, Dave. The copy of M493-13 that ITU offers for download (link above) is dated October, 2009, and says nothing about "draft" or "preliminary" or similar. Plus the Proposal for Draft Revisions to 493-13 that I also linked to is dated June, 2011, and Glenn says he'll soon be working on 493-14. So confusing.

Can either of you point us at an explanation of what the current specs mean in plainer English?

Posted by: Ben in reply to Dave Walsh at January 14, 2013 10:26 AM | Reply

In answer to your question about having received a DSC call, the answer is yes. My club publishes a roster for club cruises and some of us use it routinely.

A more interesting experience occurred offshore a few years ago when the Navy was hailing a cruise ship on 16. After finally making contact, the Navy directed the cruise ship to alter course to stay clear of a Navy vessel. AIS quickly told me that the cruise ship's new course was a collision course with mine. Rather than suffering the Navy's frustration of repeated channel 16 hails and corresponding delay, I used the cruise ship's MMSI # (shown as part of its AIS info) to place a DSC call to the cruise ship. My call was answered in about 20 seconds and we easily negotiated our passing.

Posted by: Rick O at January 14, 2013 3:12 PM | Reply

I know everyone at Standard must of lost some sleep over this recall. However I have it on good authority that the new updated radios will be shipping very soon! I am not sure if this was planned before the recall happened or not but Standard has announced the new spring rebates that go all the way to 7/31 and they are the best they have ever offered from what I have been told. http://www.standardhorizon.com/pdf/1-10-2013_Spring_Rebate.pdf

Posted by: Jason at January 14, 2013 3:54 PM | Reply

Great to hear, Rick. There's no question that DSC technology can work well; it's just seem sad that so few use it.

Meanwhile, Dave Walsh sent me the material behind his worries and it looks to me like chairman of the ITU work group is talking about the next version of M493, not the current -13 version.

But Dave still wonders if "-14 could introduce big changes to -13 so another recall?"

Which makes me think I need to take another crack at clarifying the current situation: NEITHER THE FCC NOR THE ITU RECALLED ANY RADIOS! What the FCC did here in the States was to set a 1/1/2013 deadline for radios certified to M493-13, a standard which has actually been out since 2009. Standard Horizon and others have been building radios to this standard for a long time; the hiccup was making sure that all inventory as of 1/1 is running the certified version of the software.

In short, there is no precedent for the ITU or FCC demanding changes to radios that are in the field or in inventory because they change their standard. Once M493-14 becomes real, then, yes, maybe then the FCC will set a future date when new radios have to comply. That's it, I think, and moreover DSC really isn't that hard to use on current radios.

Posted by: Ben in reply to Ben at January 14, 2013 4:08 PM | Reply

Whether it is -13 or -14, the question is how” robust” and tested is -13 which the FCC have mandated.
It has “defects” as previously described to you like polling and position request calls not being recognised by legacy equipment’s etc.

in 2008 IMO who, after all “own” GMDSS sent a liaison statement to ITU concerning, at the time M493-12 which advised “It was considered that attempts to introduce additional functionalities in DSC equipment intended for use on non-SOLAS ships has the potential to degrade the smooth operation of the GMDSS” and “IMO thanks ITU-R for their work in revising Recommendation ITU-R M.493 but advises that, since DSC is now a well-established system of some 30 years standing, any proposed changes should be confirmed by sufficient studies and testing, which could include field trials of equipment, before the changes to the system are recommended. Can the FCC produce the results of their studies and testing to prove the reliability and functioning of M493-13?
I share your sentiment"moreover DSC really isn't that hard to use on current radios.

Posted by: Dave Walsh in reply to Ben at January 14, 2013 4:51 PM | Reply

Hello all

-13 has quite a few errors.

IMHO, the FCC should not have mandated it - they should have waited for -14......


Posted by: Glenn Dunstan at January 14, 2013 5:10 PM | Reply

Oh dear, I'm sorry to hear that, Glenn. But won't it be years before anyone will see M493-14 VHF radios, and then only in new sets?

And thanks, Dave, but can you please refresh my memory on "defects previously described to you" (or by me)?

Posted by: Ben in reply to Glenn Dunstan at January 14, 2013 5:32 PM | Reply

I've had a bad enough experience with DSC to hope that there is a guaranteed way to mute the ringer for "all ship" related calls.

Antenna on a 50'+ mast. All night some kind of all ships distress alert kept on triggering the damn thing. The distances were a long days sail from our anchorage.

Finally I gave up, and just turned the radio off entirely and got my handheld going.

Posted by: Johnd at January 15, 2013 11:49 PM | Reply

Why don't they just settle on a standard interface that uses the same sequence of key-presses as a mobile phone? i.e., push the DSC button, then get a keypad that allows you to key in a DSC number. Then "Send". All the rest of the special features get separate menus to add to your contact list, or make up groups, except the emergency button, which should stay prominent on the face of the unit. Even things like the channel for communication could be an option that you set once.

Keep it simple, so that people find it easy to use. I think that the reason most people don't use it right now is because it is too complicated to use, and just calling on 16 is so much easier.

Also, there should be SOME way to tone down the volume on the call announcement. The French govt uses DSC all the time for Panne-Panne (French for "breakdown") calls, when someone runs out of gas, or needs a tow, and it is quite shockingly annoying to have the DSC alarm go off for this. Maybe it is OK for SOS, but not for out-of-gas.

Posted by: rxc at January 16, 2013 5:57 AM | Reply

We are fortunate that the FCC incorporated the ITU recommendation in their regulations, as now we can actually see what it says without having to buy it from the ITU. I very much dislike the notion that I own devices like a DSC radio or a NMEA-2000 display, and the fundamental specifications of the standard to which they were built it not available for download without purchase. With the FCC making these commendations part of US regulations, at least we can see what the recommendation or regulation has to say.

That there is complexity in the recommendation does not mean we cannot make further progress. That reaching agreement is a slow process is acceptable, given that it is a global recommendation that could affect many hundred thousands of vessels.

Among the several other boaters that I cruise with, we all have DSC radios. Most are fully integrated to the chart plotter. We often use DSC calls for position poll to keep track of our positions, and we also use DSC for voice calls. But as the USCG Admiral's letter noted, 90-percent of boaters in distress appear to not have their DSC radio installed in even the most basic interconnection to their GPS receiver or chart plotter. I suspect that means that use of DSC calling and polling features is at about that same level or lower.

It is my observation that Standard-Horizon tends to be a leader in digital selective calling features. I think they were on the ground floor of the position polling and also on the enhanced position accuracy reporting in DSC.

As for VHF Marine Band radios making strange loud noises, this can also occur in the USA if there is a weather alert transmitted by NOAA. The first time this happened I was so confused the only remedy I could employ to cancel the alarm was to switch off power to the radio. This is clearly not what the designers of the alert system intended to produce. It was only much later, after finding the manual and reading it over carefully, that I figured out the source of the alarm was due to a weather alert. I considered myself to be a sophisticated user of the radio, but I was taken by surprise buy the weather alerting.

Posted by: Jim Hebert at January 16, 2013 8:58 AM | Reply

Jim, M493-13 is widely available on the web; even free from ITU!

If you read it carefully you will note that slavish acceptance of 493-13 (Table 4.7)defines a position request as an Urgency & Safety individual call. By 493-13 such individual calls are not permitted by Class D VHF .Polling (table 4.7) has no symbol permitting same for a Class D. So, in theory, strict adherence to the recommendation will mean those “many hundred thousands of vessels ”who’s product follows pervious practice of assigning these type of call to Routine individual calls, will, in essence be rendered deaf and dumb to a strict M493-13 unit. This is just one example of the operational, practical and legal deficiencies in a “instrument” just mandated by the FCC!

They are fully aware of these “defects”; they attend ITU en masse!

Posted by: Dave Walsh in reply to Jim Hebert at January 16, 2013 9:55 AM | Reply

Gosh, Jim, I think I put the ITU 493-13 PDF link clearly into the entry above, as in:

"The ITU lets you download a complete 493-13 PDF here:


Also Dave send me more detail on 493-13 "defects", which is depressing:

"1. almost all the current product in the field will be unable to respond to a position request as M493-13 defines it as Table 4.7 and 4.9 – Individual calls Position request and Position acknowledgement are contained in Table 4.7 under the heading of Urgency and Safety calls. However existing VHF and MF/HF equipment which provides Position request facilities uses an implementation using a Routine call which is not compatible

2. Table 4.2 – Distress acknowledgments The procedures for cancelling a distress alert that was inadvertently transmitted are given in Resolution 349 (WRC-07) to the Radio Regulations. These procedures, which form the basis of operator training and also IMO Resolution A.814 (19), do not include any procedure for DSC self cancel operation. Moreover Class D and E DSC equipment does not include the capability for distress acknowledgement calls as described in Annex 2 to the Recommendation. The footnote to Table 4.2 is thus inconsistent with the Radio Regulations, IMO requirements and operator training. Similarly Paragraph of Annex 4 is inconsistent.

3 Table 4.4 – Distress relay acknowledgementsThe requirement to transmit a distress relay acknowledgement by Class D and Class E ship stations is included in Table 4.4. This is inconsistent with Annex 2 to the Recommendation which requires a receive only capability for distress acknowledgements.

4 Table 4.5 – Urgency and safety calls All ships urgency and safety calls are not included in Table 4.5. This is incompatible with existing equipment which has an all ships capability and moreover operator training includes the transmission of all ships urgency and safety calls. All ships urgency and safety calls are required for backward compatibility

These are just , in my opinion, the most important defects!"

BUT, regarding Johnd's bad alarm experience, note that one stated purpose of 493-13 is "that after experience gained, a need exists to reduce unnecessary alarms and simplify operation of shipborne equipment"

Also see "The sounding of any alarm should simultaneously display the reason for the alarm and the means to silence it."

& " Only the first occurrence of a received DSC message should sound the alarms described in
§ {Distress & Urgency}"

Posted by: BenTest at January 16, 2013 10:16 AM | Reply

It is wonderful that the specification is available from ITU for no cost. I don't think this has always been the case. I leave this sidebar to be explored further at another time. I apologize for introducing it here.

On the very insightful comment that Dave Walsh made about position request, I offer this observation:

When I used DSC to get a position report from another vessel--we were both using Standard-Horizon radios--I noticed that on my chart plotter, a Lowrance HDS-8, a waypoint was created. In the details of this object the chart plotter provided the further information that this DSC call was a "UNDESIGNATED DISTRESS" call. I thought this to be rather odd. I wrote to Lowrance to ask about this. They replied that this presentation was correct, saying "...UNDESIGNATED DISTRESS call is proper for the type of call you were receiving...."

I was skeptical, thinking perhaps that Lowrance was wrong. Or, possibly Standard-Horizon was wrong, and sent the wrong data. However, Dave Walsh's comment seems to affirm the presentation as strictly correct. That is quite interesting. I make the inference that these position reports were somewhat grafted onto the existing framework, resulting in them being categorized as UNDESIGNATED DISTRESS calls.

That seems like a poor framework. A system should not mark routine calls as UNDESIGNATED DISTRESS calls. That practice can only lead to confusion.

Posted by: Jim Hebert at January 16, 2013 12:08 PM | Reply

I hold no allegiance to the two suppliers and do not know their product in depth but the call made as you described should have been a Routine individual call!

All the problems should be ironed out when M493 eventually becomes stable and everybody including, the FCC, follow the wise words of IMO COMSAR 12 “who advised that, since DSC is now a well-established system of some 30 years standing, any proposed changes should be confirmed by sufficient STUDIES and TESTING, which could include field trials of equipment, BEFORE the changes to the system are recommended”

p.s. the capitalization is mine

Posted by: Dave Walsh in reply to Jim Hebert at January 16, 2013 12:39 PM | Reply

Navico has some problems with the FCC VHF mandate too. Apparently the Lowrance LVR-250 and LVR-880 as well as the Simrad RS10 and RS25 are not compliant with ITU M493-13 and have been, or will soon be, replaced by compliant models. Navico is asking U.S. dealers who may still have stock of non-compliant models to take them off the market and is offering an inventory swap for the newer models.

Panbo entry new models here: http://tinyurl.com/panbo-new-navico-VHF

Posted by: Ben at January 18, 2013 4:46 PM | Reply

Navico clarified its ITC compliance situation:

"Regarding the ITU-493-13 issue, we have some affected and unaffected models. Overall Navico is in pretty good shape.

Lowrance Link-5 has been shipping for some time and is fully compliant.
Simrad RS12 has been shipping for some time and is fully compliant.

First Lowrance Link-8 should be in stock in the USA next week, it is fully compliant. It replaces LVR-880 which is non-compliant.
RS35 is due in stock early March, it is fully compliant, it replaces RS25 which is non-compliant.

We have communicated what is compliant/non-compliant to the sales channel in the USA and asked for any non-compliant models to be returned for swapping to newer compliant models."

Posted by: Ben at February 5, 2013 8:21 AM | Reply

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