Opinions on DSC

[JonBrooks]

Martin

I would like to say its down to the dodgey radio you have but we both know that not to be true /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

You are right about some of the comments that end up on forums and then when people who do know the facts post they get shot down in flames!

I hope that this season there will be a change and the comments feed back from here and other forums to HMGC have made certain coutries think about the way they do things.

The biggest worry is people turning their radio's off.
This was of grave concern to me and others.

I spent all weekend on the water, around here.
Not one single DSC message or alert.
In all my time of boating around the solent, not many.

Maybe I am lucky as I am not on a sailing vessel with a large mast.

Lemain

Whilst you must back up your DSC alert with a voice call, maybe I should have made that a tad more clear, surely the whole point is to alert the large vessel you are there with no engine.
If they have ch16 turned down they will as sure as hell know you are there once you send the alert via DSC.
Then when you do the back up voice call you weill have their full attention.
Like you the commercial craft can not turn down the alarm.

IMHO nad not as Jon from Icom, I think DSC is a great enhancement to VHF if it is used in the right way.
Like all new things it will take time.
It is not going to happen and be perfect over night.
Mainly because I can't and never will be forced of the some 62,000 licenced pleasure craft in the UK.
I don't think that it should be force on us either but you have to give these things a chance.

Look what they said about mobile phones!!
I know because I worked for Vodaphone in the very early days!

Regards

 

[Robin]

Martin

I have no idea how high or low Itchen Bridge is so it is meaningless to me in terms of mast height!

However in order to receive the DSC signal, just like any VHF signal you have to be in range of the transmitter. VHF is generally line of sight range so aerial heights of both transmitter and receiver ARE very relevant. I would guess for example that on the limit of the transmit/receive range raggies will hear more DSC alarms than mobos with their lower aerial heights.

Now last year's main contender in our area in the screaming banshee stakes was Jobourg Traffic Control, they have very powerful transmitters and very high aerials mounted on the hills of the NW corner of Cherbourg Peninsular. We routinely receive JTC VOICE transmissions on both Ch16 and Ch80 from on our berth in Poole 65mls or more away. DSC signals are digital and go out on Ch70, they do not have to compete with Salty Sam or Scumisal 34 for airspace on Ch16 so their effective range is much greater - they can trigger the DSC alarm for an even bigger range radius. As I said in my earlier post, we have received JTC alarms (you can tell because the set is hijacked to Ch80, JTCs working channel) from as far away as the Morbihan in South Brittany, 250 miles away maybe by sea but maybe 130 mls away overland by Mk1 crow.

However and again as I said in my earlier post, so far this year JTC at least seems to be not sending out alarms in the same relentless way as they did last year,so I live in hope!

As far as the merits of DSC are concerned in general from a safety point of view I doubt there is much difference in practice, at least not yet. I have yet to hear a MAYDAY by DSC that wasn't a false alarm (heard a couple of those) but have heard several on Ch16 voice that were genuine, in either case the CG and others responded. In our case currently we do have DSC, but because of NMEA hook up problems it will not show our position automatically anyway, that has to be entered manually (with instruction manual in hand).

As far as the posts concerning setting off a DSC MAYDAY for a potential collision scenario are concerned I think that would be the last thing on my mind. If a big ship is close enough to cause me that amount of concern he is probably too close to do much about it whereas our ability to turn tail quickly might do the trick, I would rather be doing that than messing with the VHF!

From a non-emergency point of view DSC calling is too much hassle! I have no idea of friend's MMSIs nor they mine and even if they were programmed into our set it would still be quicker and easier to call them on Ch16.

Robin

 

[Anonymous]

Jon,[ QUOTE ]
Look what they said about mobile phones!!
I know because I worked for Vodaphone in the very early days!

[/ QUOTE ]That's a perfect analogy - from the earliest days you could personalise the type of 'ring' or 'alert' tone for the mobile and they even make it easy for you set up pre-programmable preferences for different situations such as outdoors, meeting, silent, etc. Before DSC sets become acceptable for yachts they will have to be fitted with means to set the alert tones to an appropriate level. Until they do that, they will not be acceptable. DSC will be a huge imrovement over conventional VHF once that problem is sorted out.

 

[JonBrooks]

• noun 1 anxious or frightened awareness of danger. 2 a warning of danger. 3 a warning sound or device.

Taken for the Good old Oxford.

Surely the whole point is to make us sit up and listen.
If you can turn it down that wont happen

I fully agree, understand and support the sittuation with the dear old French.
IMHO I think they were using the wrong alert for routine traffic.
Hopefully that hads changed.

My point about mobiles was that everyone at the time said they wont catch on.
Only big bosses and the rich will carry them.
Not that fact you can have any ring tone you want including Fluffy the Chick and the good old Crazy Frog! (I blame Jonny Walker for that!)
The fact that you can change and adjust the ring tone on you mobile has nothing to do with some poor sole sinking in the Solent or about to be run down by a huge vessel and need ing to let all know they need help.

Every man and his dog has a mobile now now, even my dad and he is a total anti techi type bloke!

I am sure Marconi was told "it will never catch on"!

Regadrs

 

[Anonymous]

[ QUOTE ]
From a non-emergency point of view DSC calling is too much hassle! I have no idea of friend's MMSIs nor they mine and even if they were programmed into our set it would still be quicker and easier to call them on Ch16.

[/ QUOTE ]When enough people have DSC sets and people get used to them, I suspect that this will be the most useful feature of all for those who like to be sociable. Clubs and groups can apply for their own number as well as simply entering friends' numbers individually. Hopefully it will put an end to the irritating calls that go on, and on, and on, on Ch16, like lonely hearts. I haven't heard any of the usual Sunsail calls so far this season - maybe they are all using DSC?

 

[Anonymous]

[ QUOTE ]
Surely the whole point is to make us sit up and listen.
If you can turn it down that wont happen

[/ QUOTE ]It needs to be set to an appropriate volume for the present circumstances. I have a deck saloon steering position (which is my primary steering postion, as the viz is best there) and at night, typically, one person is on watch and the other resting or sleeping. Whether under sail or engine, the noise level is low on my boat and the only artificial noises are beeps from the radar if MARPA is being used. The DSC alerts on the sets I have heard would make the watchkeeper jump out of his or her skin and wake the person sleeping. It is FAR too loud for that situation.

As Robin has already pointed out, if you are outside you need to go to the set to acknowledge the alert. Suppose the watchkeeper is on deck trimming the sails and this banshee goes off, he has to race down below to shut the wretched thing up. It just isn't appropriate for yachts, especially short-handed yachts which are becoming increasingly common as more and more couples go cruising together.

Maybe it is appropriate for a 400hp motorboat crashing along at 25kts, but not for a yacht making 7 or 8 kts in a force 4/5.

 

[Ships_Cat]

I think you are missing the point. The alarm should only go for category Distress and category Urgency alerts, in which case people should jump out of their skins.

As I stated in an earlier post (and another has said the same) shore stations are incorrectly using alarms, that is what should be addressed. But it seems from what Robin says that there has been some recent advance in correcting that.

There is very little chance (I suspect none) that the alarm will be allowed to be defeated for Class D sets. If it were to be so it would be similar to having flares that were not very bright in case you night blinded someone.

Will sit back now for the "requotes" and responses (er maybe not, I think I am in the "Ignore this User Category" with you /forums/images/graemlins/smile.gif).

John

 

[JonBrooks]

Cant argue with your thinking there.

I think the problem is that the system was designed around the commercial user.

As pleasure craft can not be force to carry radio their needs are to the back of most people in powers thinking.

As the people who make the kit we have to make them to the specs provided and have very little power to change them.
We here, and I am sure the of manufactures feel the same, do take on board the comments and feed back we get and try where possible to make the radio suit your needs.

When it comes to the alarms there is very little we can do.
With the new M421 we have made the alarm esculate rather than full on to start.

Regards

 

[Ships_Cat]

In case of any interest, and further to what Jon says about the M421, if I recall correctly the ITU standard requires the alarm to increase to 80 db at 1m from the set if not manually cancelled within 10 seconds. It does not have to give you an immediate blast, so what Icom have done makes good sense.

I do not know what the exact EU requirement is but would assume that it closely follows the ITU standard in this point.

John

 

[tome]

The EU requirements are similiar (EN 301 025). Whoever the bright spark was who embodied such a daft requirement had obviously never encountered a sailing boat at night.

Jon likes to blast around in RIBs so probably equally unaware of the problem/forums/images/graemlins/smile.gif

 

[Ships_Cat]

RIB white noise /forums/images/graemlins/smile.gif.

John

 

[JonBrooks]

[ QUOTE ]
Jon likes to blast around in RIBs so probably equally unaware of the problem

[/ QUOTE ]

Whilst my (spare) time is mainly spent on ribs and power craft I have sailed and do understand the problems you get.
I am not totally blinkered /forums/images/graemlins/grin.gif

There are a huge numer in the industry that don't even get on boats!!

Regadrs

 

[tome]

So would you agree (notwithstanding that you're not allowed to change the spec) that having a volume control on the alert would be preferable to people switching off their sets?

 

[fireball]

I could really do with the technology now found in car stereo systems where they listen to the ambient noise level and adjust their volume accordingly - so, in a boat, if we start the engine, the volume automatically increases (and alerts by a proportional level), but if we're drifting along then the volume cuts right down to a minimum level...

 

[JonBrooks]

[ QUOTE ]
So would you agree (notwithstanding that you're not allowed to change the spec) that having a volume control on the alert would be preferable to people switching off their sets?

[/ QUOTE ]

No I don't think the end user should have any control over the level of the incoming "alarm" but the level should suit the need.
As I mentioned the M421 goes some way towards this and it will be the way we recomend the radio's work in the future.
Unless the specs change there is not a lot more anyone can do.

It is an "alram" not the radio for background noise, not the ring on your mobile phone but and "alram".
Whislt we all sometimes get miffed with the alarm on the the house or car next door it needs to be load to let you know that the potential of theft is happening.

Regards

 

[tome]

Ah well, we'll just have to live with the consequences then. People will switch off (I already know this is happening).

 

[Robin]

I would agree with that too Jon and the progressive alarm is a definite improvement within the existing rules too.

As has been said if the people putting out broadcasts use the 'ALARM' function responsibly it should be OK. The jury is still out.

 

[JonBrooks]

[ QUOTE ]
Ah well, we'll just have to live with the consequences then. People will switch off (I already know this is happening).

[/ QUOTE ]

I and other are fully aware of this and in posts further up I mentioned my grave concern at this.
I have made this point to various bodies hoping to make a change.
The changes in the use by certain parties.

Regards

 

[Anonymous]

[ QUOTE ]
I could really do with the technology now found in car stereo systems where they listen to the ambient noise level and adjust their volume accordingly -

[/ QUOTE ]An excellent idea, under the overall control of a volume control that allows you to set an appropriate average level for your vessel AND the time of day and status (under sail, power, strong winds, etc.)

 

[Anonymous]

Others are likely to refit their old VHFs. I believe that users have to make a firm stand here and now to get the requirements for yachts properly re-visited and changed. I wonder what the response has been outside the UK?