A DSC alert is supposed to include your position and time of that position. WHen a GPS is correctly connected it feeds this information to the DSC radio which will display it on the screen and include it in any DSC messages transmitted.
If there is no GPS then there is provision to add this information manually however on most radios this is a fiddly time consuming excersize and the helicopter will have been and gone by the time you get the information programed.
Further to earlier answers. The DSC distress signal will contain a location and a time (i.e. the time at which the unit was given that position). So if you are entering the position manually, then those recieving the signal will be able to make allowances for the fact that you may not be where you say you are.
Whether updating manually is practical depends on the radio. If it has a proper numerical keypad, then manually entering positions is quite easy and can be done when you update the log book. On a minimalist set it is a real pain, and will probably get forgoten about pretty quickly.
I have used a Garmin handheld plus 12V lead/data connector to keep my icom dsc unit happy. The setup works well and the Garmin also drives a NASSA gps repeater in the cockpit.
All in all £180 ish well spent (repeater, leads and gps unit).
It all depends on whether you have a use/need for DSC. It's quite handy for calling stations up but the alarms can drive you mad. Some of the operating software is very clumsy, so if you want one you should play with a friend's set first, but on second thoughts, not the red button.
I just saw a cheap set in a sailing mag and wondered if it would be worthwhile for the sake of the red button but if it means all sorts of plugs, electrickery and compatability problems I shalln't bother.
I still haven't figured how to use the gps so lets not get too clever!
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Does a DSC vhf have to be linked to a gps or is it a 'stand alone' bit of kit?
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No - but if you fancy standing there typing in your position as the water rises round your legs /forums/images/graemlins/shocked.gif
The radio on the last boat took its feed from a handheld Garmin 76 which was clipped into the Garmin holster thingy and supplied with ships 12v and data cable to radio. Worked well because you could put the gps where you needed it - in front of the wheel.
I'm as careful about money as the next man (wife says tight :-( ) but I do put a higher value on my own neck than the £200 or so that a new handheld GPS costs.
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I'm as careful about money as the next man (wife says tight :-( ) but I do put a higher value on my own neck than the £200 or so that a new handheld GPS costs.
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Totally agree. money spent on any item to enhance safety is IMHO money well spent, the downside is you always hope you will never cash in the investment
In relative terms all DSC radios are good value for money.
8 years ago you could have brought, for example, an Icom IC-M59 for a SRP of £350 ish.
This unit was not fully waterproof, had a 1 year warranty and no DSC.
You can buy a fully waterproof, full DSC unit with three year warranty for about £150 now.
This unit would also be from a good brand.
Just my thoughts.
Also your hand help GPS may have data out, many do.
If so you can link this to your DSC radio.