Should all DSC radios have "position request" capability?

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Plevier

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I thought it was part of the specification, however I can't find how to do it with my Skanti VHF1000P (also known as Sailor A1 or RT4801). It doesn't seem to be there in the menus.
Anyone happen to know please?
Not trying to stalk anyone, just want to see if the position display connection to my new plotter works!
 
I'm pretty sure that the NASA DSC set on Kindred Spirit only did the bare minimum of sending and receiving distress, urgency, safety and routine calls. Certainly it had no connection for sending data out of the radio, so couldn't display anything on a plotter.

Pete
 
elton said:
Long time since I did my DSC course, but I think it only sends position with a distress call.
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No, there is a DSC "position request" call which you can use to ask someone else's radio where it is. Similarly a "position report", where you can transmit your position to someone else.

Interestingly, the default on my Standard Horizon was to respond to position requests automatically. I changed it to ask me first, displaying who is asking, so that I can decide whether I want to tell them. Presumably all the luddites who choose not to understand this stuff will have left it on the default, which may not be what they want.

(It's true that no position or identity is sent with an ordinary voice transmission, which is the other misconception people tend to have.)

Pete
 
prv said:
I'm pretty sure that the NASA DSC set on Kindred Spirit only did the bare minimum of sending and receiving distress, urgency, safety and routine calls. Certainly it had no connection for sending data out of the radio, so couldn't display anything on a plotter.

Pete
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I believe only a couple of radios have the nmea output such as Standard Vertex and not even sure how they would handle this. However most other VHF radios use the Kiss principle. They display the coordinates you plot it on a chart ;):rolleyes:
 
Troubadour said:
I thought it was part of the specification, however I can't find how to do it with my Skanti VHF1000P (also known as Sailor A1 or RT4801). It doesn't seem to be there in the menus.
Click to expand...

Our old Simrad RD68 couldn't send or receive position request/reports either whilst all the Icoms (M505 & M421) I've used have had the feature so I don't think the set has to be able to do it in order to meet the minimum requirements of the class D specification.
 
SJF said:
Our old Simrad RD68 couldn't send or receive position request/reports either whilst all the Icoms (M505 & M421) I've used have had the feature so I don't think the set has to be able to do it in order to meet the minimum requirements of the class D specification.
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Thanks. I think it must have come in later. My Skanti is pretty old (but superb VHF quality).
 
Troubadour said:
I thought it was part of the specification, however I can't find how to do it with my Skanti VHF1000P (also known as Sailor A1 or RT4801). It doesn't seem to be there in the menus.
Anyone happen to know please?
Not trying to stalk anyone, just want to see if the position display connection to my new plotter works!
Click to expand...

My Icom IC M505, relies for its positioning capability on an NMEA 083 input from the GPS receiver. If the receiver is turned off - no position. I'm not aware of any DSC radio having its own GPS receiver so, unless you know yours has an inbuilt receiver, you are probably on a fruitless quest.

The Sailor A1 does not appear to have a built-in GPS receiver.
 
charles_reed said:
My Icom IC M505, relies for its positioning capability on an NMEA 083 input from the GPS receiver. If the receiver is turned off - no position. I'm not aware of any DSC radio having its own GPS receiver so, unless you know yours has an inbuilt receiver, you are probably on a fruitless quest.
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I'm not sure what question you think you're answering, but it's not the one the OP asked :)

(For the record, there are a handful of radios with built in GPS, but I'm as perplexed as anybody as to why it's not more common.)

Pete
 
charles_reed said:
My Icom IC M505, relies for its positioning capability on an NMEA 083 input from the GPS receiver. If the receiver is turned off - no position. I'm not aware of any DSC radio having its own GPS receiver so, unless you know yours has an inbuilt receiver, you are probably on a fruitless quest.

The Sailor A1 does not appear to have a built-in GPS receiver.
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I'm afraid you are misunderstanding. Yes my DSC radio knows its own position from my GPS. I am talking about the call to request another boat's position and display it on my chartplotter through the radio's NMEA output.
 
Troubadour said:
I'm afraid you are misunderstanding. Yes my DSC radio knows its own position from my GPS. I am talking about the call to request another boat's position and display it on my chartplotter through the radio's NMEA output.
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Yes my Standard Horizon vhf radio does this and displays the position and MMSI number of the vessel whose position I've requested on my Standard Horizon chart plotter (assuming of course that the vessel has a DSC radio coupled to a GPS and both are switched on). You need two NMEA connections between radio and plotter i.e. NMEA in and out for each.
 
Yes I have those connections.
What seems to be missing - as I said in my first post - is the command to send the position request message. It does not appear anywhere in the message transmit setup menu.
 
I also have an early Skanti from 2000. As you say, it is an excellent radio but doesn't have some modern features, such as the ability to enter group MMSIs, though I believe one can be entered by a technician.
 
Troubadour said:
I'm afraid you are misunderstanding. Yes my DSC radio knows its own position from my GPS. I am talking about the call to request another boat's position and display it on my chartplotter through the radio's NMEA output.
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My apologies.

On the Icom the position of the transmitting vessel comes up as an item on a sub-menu, on receipt of a DSC call. Many modern DSC receivers seem to state it automatically.

Haven't ever tried to transfer the position to the plotter as all of the DSC calls I've received (2) have been more than 25nm away and other vessels have been closer.
It is easy enough to work out from the relative coordinates, though.
 
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charles_reed said:
On the Icom the position of the transmitting vessel comes up as an item on a sub-menu, on receipt of a DSC call. Many modern DSC receivers seem to state it automatically.

Haven't ever tried to transfer the position to the plotter as all of the DSC calls I've received (2) have been more than 25nm away and other vessels have been closer.
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Not that it matters, but it appears you still haven't grasped the subject of this thread :)

This is nothing to do with distress calls. There is more to DSC than the big red button.

A modern DSC radio will have the ability to query another vessel's position. Say I'm cruising around the Solent, and I happen to know that Dave Lusty is out this weekend in Live Magic - I might scroll down the DSC menu to "Position Request", choose his MMSI from the address book, then press "Transmit". The radio will send out the coded request on ch70. His radio will receive this, and depending on the settings (as I posted earlier) it will either ask him if he wants to reply or just go ahead and do it without disturbing him. My radio gets the response back, displays Dave's lat and long on the screen, and spits out the same information over NMEA so that the plotter can put a little icon in Dave's position.

(Actually, my plotter won't do that as I haven't yet done the necessary wiring, and in this situation I'm much more likely to just call Dave and ask him where he is!)

The OP's problem is that his radio doesn't seem to have the menu option for making the request.

Pete
 
prv said:
Not that it matters, but it appears you still haven't grasped the subject of this thread :)

This is nothing to do with distress calls. There is more to DSC than the big red button.

A modern DSC radio will have the ability to query another vessel's position. Say I'm cruising around the Solent, and I happen to know that Dave Lusty is out this weekend in Live Magic - I might scroll down the DSC menu to "Position Request", choose his MMSI from the address book, then press "Transmit". The radio will send out the coded request on ch70. His radio will receive this, and depending on the settings (as I posted earlier) it will either ask him if he wants to reply or just go ahead and do it without disturbing him. My radio gets the response back, displays Dave's lat and long on the screen, and spits out the same information over NMEA so that the plotter can put a little icon in Dave's position.

(Actually, my plotter won't do that as I haven't yet done the necessary wiring, and in this situation I'm much more likely to just call Dave and ask him where he is!)

The OP's problem is that his radio doesn't seem to have the menu option for making the request.

Pete
Click to expand...

and neither does mine unless it has first received a DSC call.
 
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