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what is dsc?
What is the DSC term used with marine VHFs?
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what is dsc?
RB wrote:
What is the DSC term used with marine VHFs? Try this: http://boating.ncf.ca/vhfdsc.html -- Kees |
what is dsc?
Good. Thanks.
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what is dsc?
Very good opinion. I do not understand why Garmin, Raymarine and Icom,
for example continue to invest in DSC; the "new" DSC Position Report feature of Garmin GpsMap 276C for example, wich demandas a VHF Radio with NMEA IN and OUT, is ridiculous. These manufacturers should instead take attention to AIS insted this "half-assed" DSC technology. Pascal |
what is dsc?
Larry and Pascal:
Isn't the momentum for DSC and GMDSS being driven by European requirements? My understanding is that implementation by the UK and other European coast guard stations is farther along than in the US. Manufacturers tend to build to meet the market's most stringent requirements. Chuck Pascal wrote: Very good opinion. I do not understand why Garmin, Raymarine and Icom, for example continue to invest in DSC; the "new" DSC Position Report feature of Garmin GpsMap 276C for example, wich demandas a VHF Radio with NMEA IN and OUT, is ridiculous. These manufacturers should instead take attention to AIS insted this "half-assed" DSC technology. Pascal |
what is dsc?
"Pascal" wrote in message oups.com... Very good opinion. I do not understand why Garmin, Raymarine and Icom, for example continue to invest in DSC; the "new" DSC Position Report feature of Garmin GpsMap 276C for example, wich demandas a VHF Radio with NMEA IN and OUT, is ridiculous. These manufacturers should instead take attention to AIS insted this "half-assed" DSC technology. Pascal DSC and AIS are two different systems to meet two different needs. AIS lets you track all the ships around you for collision avoidance and DSC lets you "select" which ship to call on the radio. When the two systems are merged the AIS display will let you pick the ship you want to talk to and call only him using DSC. Everyone else will not have to listen to your conversation. DSC and AIS use almost exactly the same digital modulation/demodulation technology so the R&D money spend on either system to adapt existing analog radio designs to digital modulation benefits the other. ------------- Here is more info concerning AIS and DSC: AIS and DSC are the new technologies for receiving position reports of other boats in your vicinity. Digital Selective Calling (DSC) is on marine VHF channel 70 (156.525 MHz) Automatic Identification System (AIS) broadcasts are on two VHF marine channels 87 (161.975 MHz) & channel 88 (162.025 MHz). Here is a link to a popular AIS receiver: http://www.nasamarine.com/AIS/AISENGINE.html Here are some web pages that further describe AIS and DSC http://www.navcen.uscg.gov/marcomms/gmdss/dsc.htm http://www.navcen.uscg.gov/enav/ais/default.htm http://www.sailmag.com/05feellison.qrk.pdf http://www.amcom.nl/marine/icom_ic_m421.htm If you want to use the sound card to decode and display AIS data on your laptop see this web page: http://www.coaa.co.uk/shipplotter.htm Here are a few more interesting links: http://www.xmradio.com/weather/ http://www.xmradio.com/weather/av_subscription_pkg.pdf http://www.garmin.com/products/gpsmap376c/ http://www.nasamarine.com/press/pdfs/sx35.PDF http://www.nasamarine.com/press/pdfs/sx35pract.PDF http://www.nasamarine.com/press/press.html |
what is dsc?
chuck wrote:
Larry and Pascal: Isn't the momentum for DSC and GMDSS being driven by European requirements? My understanding is that implementation by the UK and other European coast guard stations is farther along than in the US. True, in Europe all coastguard stations have the equipment, and so do all IMO registered ships. They are checked when they get to port. Manufacturers tend to build to meet the market's most stringent requirements. The IMO is a worldwide organization, and it has mandated GMDSS, of which DSC is a part. As of February 2005 no coastguard in the world nor any vessel is _obliged_ to listen to Channel 16. They may do so however, and this is done even in Europe. From the UK MCA website: http://www.mcga.gov.uk/c4mca/mcga-gu...comms_code.htm "While the United Kingdom Coastguard will continue coverage of VHF Channel 16 for the foreseeable future, from 1 February 2005, the Coastguard watch on Channel 16 will be downgraded from a dedicated headset watch to a loudspeaker watch. Also, from this date, ships that are currently obliged to keep a listening watch on Channel 16 where practicable, will no longer be obliged to do so." And the Dutch coastguard says: http://www.kustwacht.nl/Engels/Newsl...37E%20LW16.pdf "It is therefore that the Directorate-General Freight Transport of the Ministry of Transport and Public Works decided to continue the radio watch on VHF channel 16 in The Netherlands, for the time being for an unlimited period, after February 1st 2005. The decision of other countries in this matter is unknown. In spite of the above-mentioned decision The Netherlands Coastguard maintains its advice to seagoing yachtsmen to change over to GMDSS equipment. It is in their best interest to initiate alerts on VHF DSC channel 70 whenever the circumstances require doing so. Only in this way one stands a very good chance to be “heard”." -- Kees |
what is dsc?
Kees Verruijt wrote:
chuck wrote: Larry and Pascal: Isn't the momentum for DSC and GMDSS being driven by European requirements? My understanding is that implementation by the UK and other European coast guard stations is farther along than in the US. In follow-up, read this: http://www.navcen.uscg.gov/marcomms/gmdss/dsc.htm "The USCG plan to implement GMDSS Sea Area A1 is one element of the USCG National Distress and Response System Modernization Project, now called "Rescue 21", which replaces the whole USCG VHF distress system. On 24 September 2002, Secretary of Transportation Norman Mineta announced the award of this $612 million contract to General Dynamics Corp. Until this system is installed, the Coast Guard cannot reliably receive VHF DSC distress calls." Guess 3 1/2 years is not enough time for the US government and General Dynamics to install radio transmitters with DSC ... -- Kees |
what is dsc?
"Ted" wrote in
. net: When the two systems are merged the AIS display will let you pick the ship you want to talk to and call only him using DSC. Everyone else will not have to listen to your conversation. That's true if you stay on Channel 70 and don't listen to 16 or the other CB channels...68, 69, 71, 72, 10, 12, 13....(c; |
what is dsc?
DSC is required in all new console mount VHF radios being type
certified. Garmin made almost no investment -- just a few lines of code. All the HW was already there. They did it because Standard Horizon had it and was pusing it it. A fair number of radios have NMEA IN and OUT (mine does, and it's several years old). "Pascal" wrote in message oups.com... Very good opinion. I do not understand why Garmin, Raymarine and Icom, for example continue to invest in DSC; the "new" DSC Position Report feature of Garmin GpsMap 276C for example, wich demandas a VHF Radio with NMEA IN and OUT, is ridiculous. These manufacturers should instead take attention to AIS insted this "half-assed" DSC technology. Pascal |
what is dsc?
Most of the recreational radios scan 70 most all the time, so if there's
anybody within range with a recent radio, DSC is going to get their attention. And if you are out of range of VHF, you're out of range, DSC or not. The selective calling thing works, though ICOM's human factors to use it suck. SH's human factor are great -- both radios get set to the working channel, ring like a telephone, pick up the mike and talk. That's it. "Larry" wrote in message ... "RB" wrote in news:ol5Lf.25391$Ly6.24795 @bignews5.bellsouth.net: What is the DSC term used with marine VHFs? A half-assed, 1980's digital technology invented to call one ship from another so shipping companies can eliminate the expensive crew position of radio officer the unions used to force upon them with government intervention. It was poorly planned, draggedly implemented causing its effectiveness to be very poor in emergency conditions. The attempts to implement it in yacht transcievers with only a one-push- button emergency mode plus a one-at-a-time selective calling feature is nearly useless as the radios only switch to Channel 16 for FM voice if someone within the 10-15 miles of VHF range happens to be listening to DSC's channel 70, which only the ships are, forced by international law to do so. If you're "out there" and cannot see a ship on the horizon and are further than 20 miles at sea, noone will hear the call....so don't think DSC is going to save you any more than channel 16 is under these conditions. Buy a 406 Mhz EPIRB with a GPS receiver in it and properly register it. "They" are listening to it because "they" are using it to save their own asses. http://www.noaanews.noaa.gov/stories/s1199.htm |
what is dsc?
"Pascal" wrote in message oups.com... Thank You very much. I know the diference betwen the two (DSC and AIS) , but I am not concerned with distress comunications with others ships or coast guards, but am looking for AIS to get the ships information to avoid any potential colision danger and for fun in the sea. Praticaly, here in Brazil, DSC do not exist, and here the so called Coast Guard does not exist either, only a very few of the navy ships and some airplanes (all obsoletes, without AIS) do to surveilance os the imense brasilian coast (about 3,000 nm), so a mayday in the sea is almost a null attempt. "DSC and AIS use almost exactly the same digital modulation/demodulation technology so the R&D money spend on either system to adapt existing analog radio designs to digital modulation benefits the other" Exactly, why do not include (combine) an AIS Modem (Chanel 87/88) and the AIS software into the recent launched Standard Horizon CVP350VHF/DSC radio/plotter, for example? Regards Pascal I couldn't find information concerning a standard horizon model cpv350 anywhere on the net. I suspect that the problem is the display firmware. Manufacturers such as standard horizon already make GPS chart plotters that can handle one or a few waypoints from a DSC receiver but I suspect that their firmware in the display cannot handle the hundreds of complex waypoints that would come flooding in from an AIS decoder. The display firmware will need to be significantly enhanced to show not only lat and lon but the direction the ship is pointing and the speed of the ship. |
what is dsc?
It's CPV350, not CVP350.
http://www.standardhorizon.com/index...3&isArchived=0 I found it no sweat on SH's website. "Ted" wrote in message .net... "Pascal" wrote in message oups.com... Thank You very much. I know the diference betwen the two (DSC and AIS) , but I am not concerned with distress comunications with others ships or coast guards, but am looking for AIS to get the ships information to avoid any potential colision danger and for fun in the sea. Praticaly, here in Brazil, DSC do not exist, and here the so called Coast Guard does not exist either, only a very few of the navy ships and some airplanes (all obsoletes, without AIS) do to surveilance os the imense brasilian coast (about 3,000 nm), so a mayday in the sea is almost a null attempt. "DSC and AIS use almost exactly the same digital modulation/demodulation technology so the R&D money spend on either system to adapt existing analog radio designs to digital modulation benefits the other" Exactly, why do not include (combine) an AIS Modem (Chanel 87/88) and the AIS software into the recent launched Standard Horizon CVP350VHF/DSC radio/plotter, for example? Regards Pascal I couldn't find information concerning a standard horizon model cpv350 anywhere on the net. I suspect that the problem is the display firmware. Manufacturers such as standard horizon already make GPS chart plotters that can handle one or a few waypoints from a DSC receiver but I suspect that their firmware in the display cannot handle the hundreds of complex waypoints that would come flooding in from an AIS decoder. The display firmware will need to be significantly enhanced to show not only lat and lon but the direction the ship is pointing and the speed of the ship. |
what is dsc?
"Larry" wrote in message ... "Ted" wrote in . net: When the two systems are merged the AIS display will let you pick the ship you want to talk to and call only him using DSC. Everyone else will not have to listen to your conversation. That's true if you stay on Channel 70 and don't listen to 16 or the other CB channels...68, 69, 71, 72, 10, 12, 13....(c; I'm not sure why they dont implement DSC on all VHF marine channels. Maybe they will in the future after it is proven on channel 70. Do the current DSC capable radios allow you to use DSC on channels other than 70?? |
what is dsc?
On Sat, 25 Feb 2006 02:23:31 GMT, "ted" wrote:
I'm not sure why they dont implement DSC on all VHF marine channels. Maybe they will in the future after it is proven on channel 70. You miss the point. Channel 70 is the calling channel for DSC, not the working channel, just as channel 16 is the calling channel for voice. |
what is dsc?
And Larry seems to think that radio has to be tuned to 70 to receive DSC calls.
It doesn't. It scans 70, as nearly as I can tell, no matter what you do. It least my SH Spectrum does, as does a buddy's more recent SH, and another buddy's Icom. "ted" wrote in message .net... "Larry" wrote in message ... "Ted" wrote in . net: When the two systems are merged the AIS display will let you pick the ship you want to talk to and call only him using DSC. Everyone else will not have to listen to your conversation. That's true if you stay on Channel 70 and don't listen to 16 or the other CB channels...68, 69, 71, 72, 10, 12, 13....(c; I'm not sure why they dont implement DSC on all VHF marine channels. Maybe they will in the future after it is proven on channel 70. Do the current DSC capable radios allow you to use DSC on channels other than 70?? |
what is dsc?
"Wayne.B" wrote in message ... On Sat, 25 Feb 2006 02:23:31 GMT, "ted" wrote: I'm not sure why they dont implement DSC on all VHF marine channels. Maybe they will in the future after it is proven on channel 70. You miss the point. Channel 70 is the calling channel for DSC, not the working channel, just as channel 16 is the calling channel for voice. Perhaps I did miss something here. Are you saying that there is never any voice on channel 70, but only a digital data exchange and then both ships radio's change freqency to a working channel? Who decides which working channel to switch to? Does the radio check to make sure the channel is not in use first? I assume that the voice communication on the working channel is analog and can be heard by traditional radio equipment? |
what is dsc?
There is never any voice on 70, only data, at least in theory. DSC radios
won't let you do voice on 70. Dunno about older radios. For the emergency button, 16 is working channel. For individual calls, the calling human sets the working channel prior to the call. The radio does not check that the working channel is free. It's normal analog voice comms on the working channel. "Ted" wrote in message ink.net... "Wayne.B" wrote in message ... On Sat, 25 Feb 2006 02:23:31 GMT, "ted" wrote: I'm not sure why they dont implement DSC on all VHF marine channels. Maybe they will in the future after it is proven on channel 70. You miss the point. Channel 70 is the calling channel for DSC, not the working channel, just as channel 16 is the calling channel for voice. Perhaps I did miss something here. Are you saying that there is never any voice on channel 70, but only a digital data exchange and then both ships radio's change freqency to a working channel? Who decides which working channel to switch to? Does the radio check to make sure the channel is not in use first? I assume that the voice communication on the working channel is analog and can be heard by traditional radio equipment? |
what is dsc?
On Fri, 24 Feb 2006 21:01:32 -0800, "Chuck Tribolet"
wrote: And Larry seems to think that radio has to be tuned to 70 to receive DSC calls. It doesn't. It scans 70, as nearly as I can tell, no matter what you do. It least my SH Spectrum does, as does a buddy's more recent SH, and another buddy's Icom. The SC-101 class radios allow the user to disable the channel 70 scan, effectively disabling DSC reception. My brother-in-law's new Icom 502 came set that way - confused us when I tried some DSC tests with him - his older, cheaper Icom could receive my calls regardless of the selected channel, but the new expensive unit had to be set to 70. (He discovered this setting while reading the book later in the day, after we'd left our boats - we assume that DSC reception will work as expected once he enables the Ch70 scan) -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
what is dsc?
In article ,
"Chuck Tribolet" wrote: And Larry seems to think that radio has to be tuned to 70 to receive DSC calls. It doesn't. It scans 70, as nearly as I can tell, no matter what you do. It least my SH Spectrum does, as does a buddy's more recent SH, and another buddy's Icom. I think that you should qualify your above statement, a bit. You should state that, "Your radio receiver scans VHF Marine Ch 70 while it is not transmitting, and you think your buddies radios do as well". There are a lot of DSC Equiped radios that may or may not, scan VHF Marine Ch 70, or may or may not have a dedicated Ch 70 Receiver builtin. Just how each model radio's Scan Routine is implimented by the OEM is propritary, and problematic, to how it responds to a DSC Signal. There are some radios that don't receive on CH 70, while the receiver is receiving a signal on the programed channel, and some that don't recieve on Ch 70 while the radio is on Ch 16. DSC in the Western Hemisphere is still mostly under implimented, and untill the USCG, and other Governmental Entities, catch up with their European Counterparts, the OEM's aren't really going to get the Consumer Type Radios up to dealing with DSC with a full implimentation. Bruce in alaska -- add a 2 before @ |
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