DSC Enabled VHF Radios

[freelancer]

Thinking about upgrading to a DSC VHF Radio. I understand that you have to sign up for a MMSI number, what then? I read that you can make phone calls on your radio and send distress info with a push of a button. Does anyone have experience with capabilities of this type of VHF Radio?

 

[Fireman431]

Re: DSC Enabled VHF Radios

Not sure about the phone calls, but my understanding was that your vessel ID would be available to other boaters with the DSC radio and vessel info would be automatically transmitted in the event you activated the red MAYDAY button.

 

[Boatist]

Re: DSC Enabled VHF Radios

Re: DSC Enabled VHF Radios
You can call the marine operator on your radio but it is not cheap. Major ports have some channels for marine operator to use that you can call and with the proper billing they will call on land line and patch you together. This is not new and has nothing to do with DSC.

All fixed mount radios sold in the USA today must have DSC Class D. Class D means the radio has a seperate radio channel 70 that it always monitors.
With your boats MMSI Number programmed in and radio hooked to a GPS then when you hit the RED DSC button the radio will send a distress call out in about 1/3 of a second and it will keep sending it until it receives a reply back from a shore station. The message will give the Coast Guard your MMSI number which tell the coast gaurd who you are and a discreption of your vessel. The message is sent with 1 watt on channel 70. When the coast guard replys it will switch your radio to channel 16. The coast guard will call you on channel 16. They will know what boat they are looking foor and where it is but they will still want to know the number of people on board and the nature of distress. Some radios you can put in the nature of distress before sending.
Other vessels with DSC will also get information and if your DCS Distress call does not get a land based reply there radio will try and relay the message to shore.
Coast guard calls it taking SEARCH out of search and rescue.

Coast Guard task called RESCUE 21 is to be able to pick up any distress call form any vessel using 1 watt on channel 70 out 30 miles or less for the entire Coast of the USA.


http://www.youtube.com/watch?v=M-f4nhnBThg

http://www.youtube.com/watch?v=mdkxsWBncSc&feature=channel

http://www.youtube.com/watch?v=JQk5MRwuxgo&feature=channel

 

[freelancer]

Re: DSC Enabled VHF Radios

Good info guys, so if all new VHF radios come with Class D DSC rating, are other ratings available that would give you different options or power etc? And are they worth a potential increase in price; most importantly, if one doesn?t have the supporting electronics to realize the full range of options. For example, do I need to upgrade other electronics if I want to go down this road?

 

[Boatist]

Re: DSC Enabled VHF Radios

Yes there other classes but Class D is an upgrade.
Class SC101 was used by a lot of boats but was band from being inported, sold, or installed on March 25 2011. SC101 did not have a seperate reciever on channel 70 so if somone put out a DSC Distress call you would not know it unless you were tuned to chanel 70. Since your required to listen to channel 16 when the radio is not in use most DSC Distress call were missed.

Understand the DSC Distress call is only one fuction of the DSC.
If you know another boats MMSI number you can poll it and find out where they are. Example Your fishing buddy call you on the radio and tell you Salmon fishing is red hot where they are, two fish on all the time. Instead of telling everyone where he is on the radio you call poll his MMSI and head right to his position. No body else will know.
I also know the recent upgrade to Class D also upgraded some functions of the new units.
An example is some models would relay the DSC Distress call but insert their own MMSI number or postion instead of the vessel in distress. The new units will relay the distress vessel info.
Some models include the vessel course an speed as well as position.

For it to work it must be hooked up to a compatible GPS.
Most GPS units will have a output to hook up. It must have the right speed and match the same format to work but most new Radios will support older formats and speeds.
Under stand DSC Class D can do much more like poll or send message to a whole group of boats.

Yes there are other Classes like class A that the Coast Guard would have to send a reply and turn off your unit constant sending after they got the message.

I would not consider Myself an expert and am going to add a second radio to my boat.
I am trying to deside if I want to get a radio that also has AIS reciever.
(Automatic Identification System) is something that larger boats as Ships are required to have.
It gives their position and speed.
In the fog in San Francisco or offshore you can see where large ships are.
Also some sites it will tell you what type they are and even show you a picture.

http://www.marinetraffic.com/ais/

 

[jhebert]

Re: DSC Enabled VHF Radios

...if all new VHF radios come with Class D DSC rating, are other ratings available that would give you different options or power etc?

Actually, all new radios are not DSC equipped, and you can get a VHF Marine Band radio without DSC if you want. But, if a radio is DSC capable, it now (since March of 2011) has to comply with the CLASS-D qualification. As a recreational boater you will not be interested in any other class of DSC fixed radio. They will be much too expensive and much too large to install on a recreational boat. You can get handheld radios that are DSC rated, but they also tend to be more expensive. Personally I would recommend a fixed radio installation over a handheld radio.

...And are [DSC radios] worth a potential increase in price [?]

The price increase is very nominal, perhaps about $25 to $50 compared to similar radios without any DSC features. The value of the DSC radio for emergency notification is only realized if you connect the radio to a source of your actual position, such as a GPS receiver, and if you register your boat and obtain an MMSI which has accurate data kept up to date.

..do I need to upgrade other electronics if I want to go down this road?

To make use of a digital selective calling radio you will need a GPS receiver with a NMEA output that can interface to the radio. If you want to use advanced features of the digital selective calling radio, such as display of the position of other vessels on your chart plotter, you need a chart plotter that has a NMEA interface to the radio and also supports the NMEA-0183 sentences DSC, DSE, DSI, and DSR.

Your decision to get a modern CLASS-D DSC radio should be based on the recommendation of the United States Coast Guard. The USCG has recently spent several hundred million dollars upgrading their radio system to be able to take full advantage of digital selective calling emergency notifications. The USCG recommends that recreational boats voluntarily equipped with a VHF Marine Band radio should install a VHF Marine Band radio rated to CLASS-D DSC. However, if you want to save $25 you can ignore that recommendation.

If you purchase a DSC radio, you must connect it properly. A recent report from the USCG said that an alarming 90-percent of distress calls generated by DSC radios contained no position information. That is, the goof-ball boaters bought a DSC radio and did not properly connect it to a source of position information like a GPS receiver.

That same report also said that 60-percent of the calls were from radios that did not have an MMSI registered.

If you decide to spend the extra $25 on a DSC radio, please join that elusive ten-percent of boaters and actually connect your GPS receiver to it, and also register an MMSI and keep the information accurate.

 

[freelancer]

Re: DSC Enabled VHF Radios

DONE!
I upgraded to a new DSC capable ICOM VHF that should tie in well with the Raymarine C90W. Also went to the Boat US website and registered for the MMSI. I'm looking forward to joining the 10% club for sure; the MMSI will be programmed into the unit this weekend. I can?t wait to see how this new equipment works underway; I hope its user friendly. Thanks.

 

[jhebert]

Re: DSC Enabled VHF Radios

When you program the VHF Marine Band CLASS-D DSC radio with your MMSI, be very careful not to make an error. A DSC radio can only be programmed once with an MMSI, and if you make a mistake you will have to return the radio to the manufacturer for re-programming. The reason for this restriction is to prevent users from changing the MMSI of their transmitter on a willy-nilly basis.

Connecting the radio to a GPS receiver can be somewhat confusing to the average boater, particularly the boaters who can't read the instructions. However, most current marine electronic devices have clear instructions on how to interconnect to other devices using NMEA-0183 serial data connections. The connections follow a simple paradigm: connect an output of one device to an input on the other device. For example, to connect the GPS receiver to the radio so the GPS receiver position data can be sent, you use an OUTPUT from the GPS receiver and connect it to an INPUT on the radio.

It sounds like you have selected good equipment. You should have few problems connecting the devices, as I am confident their owner's manuals will have plenty of good information to help you.

 

[LippCJ7]

Re: DSC Enabled VHF Radios

great info guys, thanks for the videos Boatist!! very helpful!

 

[jhebert]

Re: DSC Enabled VHF Radios

--thanks for the videos Boatist!! very helpful!

Re the video at http://www.youtube.com/watch?v=M-f4nhnBThg

I believe there is some misleading information in the video linked above regarding automatic relay of DSC DISTRESS messages. I do not believe that a CLASS-D DSC VHF Marine Band radio operates as described in the video presentation. The presentation may be out of date or the presenter not completely familiar with the topic.

My understanding is that a CLASS-D DSC radio does not automatically re-transmit or relay DSC DISTRESS MESSAGES. See

http://www.navcen.uscg.gov/?pageName=mtDsc

for a description of the capabilities of CLASS-D radios.

 

[freelancer]

Re: DSC Enabled VHF Radios

Got a friend that?s a marine electrician and has done it before. I'm heading back to the boat now, we'll be extra careful to program the MMSI correctly.

 

[Outsider]

Re: DSC Enabled VHF Radios

SC101 did not have a seperate reciever on channel 70 so if somone put out a DSC Distress call you would not know it unless you were tuned to chanel 70.

My SC101 radio will receive all DSC distress calls regardless of the selected channel provided the radio is neither transmitting nor receiving, andCh 16 is automatically selected. Not as reliable as Class D, but doesn't require sitting on 70, either.

Also, my radio allows input of an MMSI twice ...

 

[jhebert]

Re: DSC Enabled VHF Radios

My SC101 radio... allows input of an MMSI twice

This is common on older DSC radios, but you will be unlikely to find this option on any of the newer radios which conform to the newer regulations regarding digital selective calling radios.

Older radios already in service which are rated for RTCM SC-101 may continue to be used, but their manufacture, import, sale, and installation in the United States is now prohibited by federal regulations.

 

[fairbank56]

Re: DSC Enabled VHF Radios

Re the video at http://www.youtube.com/watch?v=M-f4nhnBThg

I believe there is some misleading information in the video linked above regarding automatic relay of DSC DISTRESS messages.

Misleading is putting it lightly. I just came across that video a few days ago and was totally shocked at what I heard. I cannot believe that a Coast Guard Lt. is putting this out, and where in the heck did he get his DSC training??? No class of VHF DSC radio has ever had the capability to auto-relay a DSC distress call. While class A units can do it manually (class D aren't even capable of it), there were rules put in place over 10 years ago prohibiting it. His presentation and answers to questions are full of errors.

DSC radio's automatically relay distress alerts from boat to boat. INCORRECT
DSC radio's will transmit DSC data if they don't have an MMSI. INCORRECT
DSC radio's will simultaneously transmit DSC data and voice. INCORRECT (class D)
The MMSI is specific to the radio itself, there cannot be two MMSI's that are the same. INCORRECT
You can send messages from boat to boat just like text messaging. INCORRECT.
What constitutes a mayday/distress situation is not written policy. INCORRECT
The only thing he really gets correctly, is where he says he gets confused easily

I have sent emails to the CG and to Radiolabs (producer of the video) trying to get this corrected. How many radio operators and potential operators have already been grossly misinformed? I came across this forum in my search's on this travesty of information. There are people in other boating forums that are passing along this garbage. One guy feels safe in the knowledge that his fixed unit will auto-relay his distress call from his DSC handheld he keeps attached to his pfd in the event that he goes overboard. Not going to happen! My background is 36 years as a marine electronics service technician. Most likely, this is just a case of one individual who doesn't have a clue as to what he is talking about as the CG does have other video's about DSC that get it right. Unfortunately, that one video on the Internet, with Coast Guard all over it and presented by a CG officer, is like a bad infection.

BTW, distress calls go out on high power (25w), not 1w and many current class D radio models allow two entries of an MMSI before locking you out.
Also, your radio will switch to channel 16 shortly after sending the distress call, not by CG DSC acknowledgement. They will be trying to contact you via channel 16 as may be other vessels in the area that got your DSC alert.

All new fixed mount radio's are class D DSC. While you may be able to purchase and install a non-DSC or SC-101 radio, it is illegal to do so. The report about 60% of DSC distress calls having no MMSI is either BS or was read incorrectly as the radio will not transmit any DSC data without an MMSI.

Eric

 

[jhebert]

Re: DSC Enabled VHF Radios

The report about 60% of DSC distress calls having no MMSI is either BS or was read incorrectly as the radio will not transmit any DSC data without an MMSI.

Eric

The report I refer to was a letter from a USCG Rear-Admiral R.E. Day to the NMEA in which he cited those statistics. The letter was published here:

http://www.nmea.org/Assets/20110223_2000_nmea_ltr.pdf

 

[sschefer]

Re: DSC Enabled VHF Radios

The report I refer to was a letter from a USCG Rear-Admiral R.E. Day to the NMEA in which he cited those statistics. The letter was published here:

http://www.nmea.org/Assets/20110223_2000_nmea_ltr.pdf

The report is correct.

 

[fairbank56]

Re: DSC Enabled VHF Radios

The report I refer to was a letter from a USCG Rear-Admiral R.E. Day to the NMEA in which he cited those statistics.

I misread your previous post, sorry about that. 60% did not have a registered MMSI. This means people either using bogus numbers or the CG was unable to get boat/user information from the received MMSI for whatever reason. Without a programmed MMSI, the radio's cannot transmit any DSC data, including a distress alert, plain and simple.

Eric

 

[NetDoc]

Re: DSC Enabled VHF Radios

My new radio is DSC enables, and I also carry a Nautilus Lifeline. Its a GPS/VHF handheld for divers. It's rated to 400 ft and is waterproof on the surface when the case is open.

 

[fucawi]

Re: DSC Enabled VHF Radios

My experience was that the coast guard were not monitoring the DSC output ie position etc so you should check in your location if its worth it .....

 

[fairbank56]

Re: DSC Enabled VHF Radios

Nearly the entire coastline of the lower 48 states have the CG's Rescue 21 system up and running which includes monitoring DSC. See the CG's website and coverage map for further details.

Eric