Radio course

[deputydawg]

Just booked myself on a GMDSS/VHF course ,is this the latest course ? and what is dsc, and should this cover the lot!! the course is run by adult education.

<hr width=100% size=1>

 

[AIDY]

Yup that's the right course. a one day course covering vhf in the morning and dsc in the afternoon with exam.

regarding DSC this may <A target="_blank" HREF=http://www.mcga.gov.uk/c4mca/gmdss.pdf> Help </A>

<hr width=100% size=1>/forums/images/icons/wink.gif <font color=blue> Regards Andy </font color=blue>

 

[Ocean_Deep]

Don't you need to connect your GPS to your DSC-capable VHF to get much benefit? Otherwise surely you only automate the shout for help but still need to give a voice mayday to get your pos/nature of distress/description out??? Or have I missed something?

<hr width=100% size=1>Rgds

Ocean Deep

 

[Solitaire]

So you found your way here Simon! Best you and I sit down and I'll run you through the whole thing. DSC is really only a paging system that will effectively "switch" all DSC enabled sets to Ch 16 on "hearing" a DSC alert. Yes, to give an updated GPS position it will need to be connected to a GPS, but you can also manualy enter a position which the set will store for 4 hours -- mind you that's not much good if you've been travelling at 20 knots for 3 hours and come to grief!

A DSC alert is sent on Ch70 as a burst of digital pulse and does not obviate you having to make a voice Mayday call in any event.

You will need to update your old VHF certificate if you have a DSC VHF radio on the new boat.

I'll explain more when we next speak.

Oh welcome to the forum by the way /forums/images/icons/wink.gif

<hr width=100% size=1>Boating is <A target="_blank" HREF=http://www.powerboattraininguk.co.uk>Serious Fun</A>

 

[BrendanS]

The answer is yes, you do need to connect a gps or plotter, or manually input the position every so often. But you should be taken automatically to voice, and give a mayday as normal, after hitting the button. The DSC should give as much information as you have entered, and if connected to a gps, then the coastguard and other vessels will have your position and nature of emergency logged on their dsc system. Voice call follows

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[Jinks]

The other relevant point, I believe, is that HMCG will cease to monitor Channel 16 in the near future and DSC will be the only method of issuing a general cry for help.

I think that's right.

<hr width=100% size=1>Of all the things I've lost - I miss my mind the most!

 

[Cymraeg]

Yep - from Feb 2005 HMCG will no longer have a dedicated watch on Ch. 16

<hr width=100% size=1>

 

[Jools_of_Top_Cat]

I do wonder which coastguard will be the first to unplug the headphones and put 16 on a speaker and have no dedicated listener. Considering the recent report which kicked the MCA in the goulies, I know I wouldn't want to be the manager that makes that decision.

Be interesting to see what actually happens in Feb 2005

<hr width=100% size=1>Julian

<A target="_blank" HREF=http://www.topcatsail.co.uk>

</A>

 

[BrendanS]

Already been done!
here

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[Its_Only_Money]

Hmmm - has anyone tried this yet? Ch16 in the Solent on a weekend can be a continuous stream of signals overlaying each other, does DSC calling really work in such a signally-confused area.

I'm thinking of the yachy in Cowes week a few years back that lost a man overboard, many news services carried a Coastguard recording of the Mayday and it was pretty indistiguishable even when you knew there should be a Mayday to be heard in the 15secs or so broadcast. Once your DSC set switches to voice presumably the voice message would be subject to the same signal degradation - but does the DSC call itself stand any better chance of getting through as when all said and done it is a tone call on VHF, not a digital signal AFAIK.

Anyone any practical experience either way to relate???

Its Only Money (previously Ocean Deep)

<hr width=100% size=1>

 

[BrendanS]

DSC calls on Ch70, not 16, so there will be no interference. There should be no interference anyway, as the signal is indeed digital, not analogue. The clue is in the name DSC which stands for Digital Selective Calling

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[Oldhand]

Yes DSC does work and eliminates using channel 16 as a calling channel. If everyone had DSC and knew the MMSI number of their radio "mates" and didn't find it necessary to make a radio check everytime they stepped on their boat, we could be deafened by the silence on channel 16.

The DSC distress call has a very much higher chance of being received by the CG in the situation you mention. If the DSC call is made with GPS position input and the type of emergency is selected before the red button is pressed, the pressure to try and pass the information on channel 16 is much reduced as the CG will have the basic information to work with. Can't remember exactly, my books are onboard, but your DSC VHF will repeat the digital channel 70 alert for some time at regular intervals until a DSC acknowledgement is received. This acknowledgement is a digital signal sent back by a receiving station with class "A" DSC equipment, i.e. the CG. Thus if your distress priority is getting into a liferaft and not hanging around the radio, DSC has a huge advantage.

<hr width=100% size=1>

 

[Solitaire]

A DSC distress "call" will repeat itself every 4 minutes untill an acknowlegement is received from a CG station. Unless of course the vessel has sunk or met its demise in some way as to render the the radio inoperable. The routine on receiveing a DSC alert - which should be followed up any way after about 15 seconds with a normal voice call by the initiator (even if a DSC acknowledgement has not been recieved) is for any vessel to A) Inform the skipper of your vessel - if your the skipper you all well and good - B) write down the message and C) establish the position. If after 4 mins, if no acknolwegement is made to the DSC call then a "Mayday Relay" should/may be considered.



<hr width=100% size=1>Boating is <A target="_blank" HREF=http://www.powerboattraininguk.co.uk>Serious Fun</A>

 

[Its_Only_Money]

Thanks for the clarification - guess I'll have to update my qualification and radio in due course.

<hr width=100% size=1>Rgds

Simon

 

[Solitaire]

We'll sort it out when you next down.

<hr width=100% size=1>Boating is <A target="_blank" HREF=http://www.powerboattraininguk.co.uk>Serious Fun</A>