DSC position request

[jwalker]

Is it a normal function of the DSC system that a VHF will automatically respond to a Position Request from another DSC VHF?

[Jimbo]

No, it should come through as an alert, which you can either accept or reject.

It's also called Polling Request on some sets.

[Mark Halliday]

JW
The answer is ......... yes and no.
You can either enable or disable auto-respond.

If you have an Icom it will be burried at the bottom of the menu tree somewhere. {Sorry JB}

Why?
Has the missus been using it to try and find out where you are?

BTW. Nice trailer drawing. What software?

[jwalker]

Originally Posted by Mark Halliday

Why?
Has the missus been using it to try and find out where you are?

Thanks guys.

I've been investigating VHF radios and it was a point I wasn't clear about. I was looking at a Raymarine unit and it can place a position from a request onto a plotter.

It occurs to me that it could be good to permanently enable the response if that facility is available cos, in the event of a distress, a radio could poll you to find out where you are. You could also poll your boat or radio if either were stolen. You never know, you could get lucky.

The drawing software is GFA Draft. It's old Atari ST software but it's so good I stick with it. It's running in an emulator.

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Ok another DSC Q while I'm here. If I make a routine DSC call to the CG and, say, I choose Ch 06, when I get the acknowledgement my radio should tune to Ch 06 also but it doesn't. My radio changes to Ch 16. Is the radio quirky or does the CG have the facility to change a calling radio to a channel of their choice?

[Jimbo]

Originally Posted by jwalker

Ok another DSC Q while I'm here. If I make a routine DSC call to the CG and, say, I choose Ch 06, when I get the acknowledgement my radio should tune to Ch 06 also but it doesn't. My radio changes to Ch 16. Is the radio quirky or does the CG have the facility to change a calling radio to a channel of their choice?

Yup - correct on the second. When you send a DSC alert to the Coastguard (and your radio can tell it's a coast station as the MMSI has 2 leading zeros) on most sets your option to choose the channel disappears, and on all sets it won't send a channel out regardless, so the coasties can hit you back with whichever channel they want.

Just a quick note, when the acknowledgement comes through from the coastguard, and your set gets taken to whichever channel, it is then down to you to call the coastguard - don't wait for them to make contact!

[jwalker]

Thanks for that, Jimbo.

Originally Posted by Jimbo

.. it is then down to you to call the coastguard - don't wait for them to make contact!

Aye, I'm aware of that. This must be a point of misunderstanding, I've read it a few times recently.

[Jimbo]

Originally Posted by jwalker

Thanks for that, Jimbo.

Aye, I'm aware of that. This must be a point of misunderstanding, I've read it a few times recently.

Yup it is indeed. I did however hear something else that interested me today - from the RYA at the boat show. I was aware that the CG had a preference to you alerting them via DSC for routine comms, as it was more convenient for them, and thought that was the case across all CG's. However, the RYA Representative (she doesn't like her name in print!) from the Cruising Dept. tells me that Solent CG still prefer that small craft call them direct, by voice, on 67.

I knew they didn't like routine comms to them on 16 - but thought they would welcome DSC alerts? I'm going to pop to the MCA tent tomorrow and ask them direct.

[jwalker]

I can understand that, cos it just adds an extra layer. DSC ->Ch16 -> Ch67. It seems to me that a reply on 67 or another chosen channel would make sense since you're going to end up there anyway. I'm aware that, in this area, when moving from 16 to 67, it's a different person handling 67.

[Jimbo]

Originally Posted by jwalker

I can understand that, cos it just adds an extra layer. DSC ->Ch16 -> Ch67. It seems to me that a reply on 67 or another chosen channel would make sense since you're going to end up there anyway. I'm aware that, in this area, when moving from 16 to 67, it's a different person handling 67.

Not necessarily - the coastguard controllers will take you to any channel when you DSC alert them. So, in fact, it is as simple as DSC -> CH67, which is why the other Coastguards like it so much!

[mark-f]

Originally Posted by Jimbo

Yup it is indeed. I did however hear something else that interested me today - from the RYA at the boat show. I was aware that the CG had a preference to you alerting them via DSC for routine comms, as it was more convenient for them, and thought that was the case across all CG's. However, the RYA Representative (she doesn't like her name in print!) from the Cruising Dept. tells me that Solent CG still prefer that small craft call them direct, by voice, on 67.

I knew they didn't like routine comms to them on 16 - but thought they would welcome DSC alerts? I'm going to pop to the MCA tent tomorrow and ask them direct.

Yep they all seam to have their different practices, recently I called Thames up on 67 and was almost told off for doing so, they said the correct protacol is to call them on 16.

ho hum


Mark