Which GPS receiver for a DSC VHF?

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Pavel

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Hiya,
I've got a cheap and cheerful ICom 411 onboard, and want to hook up a GPS receiver to it as well.
The question is, which one? The radio takes NMEA0183. The branded ones - ICom, Garmin and the like - go for anything from 70 quid. The cheapest "no name" one I've found was about £50.
Not that I am tight, but the generic GPS receivers start from about £15. So what's the plot, then? Is this another case of something shooting threefold in price when the word "marine" is added to the product description, or are there real reasons for it?
And most importantly, could you recommend a cheap NMEA GPS receiver? Is there a way of wiring a generic one to the radio?
 
Pavel said:
Hiya,
I've got a cheap and cheerful ICom 411 onboard, and want to hook up a GPS receiver to it as well.
The question is, which one? The radio takes NMEA0183. The branded ones - ICom, Garmin and the like - go for anything from 70 quid. The cheapest "no name" one I've found was about £50.
Not that I am tight, but the generic GPS receivers start from about £15. So what's the plot, then? Is this another case of something shooting threefold in price when the word "marine" is added to the product description, or are there real reasons for it?
And most importantly, could you recommend a cheap NMEA GPS receiver? Is there a way of wiring a generic one to the radio?
Click to expand...

i bought a usb gps from amazon @ around £30
 
Well, I was thinking about something like that. The radio has literally just a wire hanging out - NMEA plus and minus - for the GPS, so I could chop the USB jack and connect them up. I'd net to get the power from somewhere, but that's not inconceivable. The data format compatibility is a different matter, though.
 
You can do this with a serial GPS mouse like the GlobalSat BR-355. You cannot do it with a USB one as you suggest. Search on Ebay for BR-355, they are available for £24. You also need to make up a 5V power supply if you want to run it on your boat's 12V system. A USB cigar lighter power supply has right parts in it. Search on Ebay for "car usb charger". They cost £1. You will need to do a bit of soldering and fiddling around, but it's what I have on my boat and it works.
 
Last edited:
Hi Angus,
That's exactly the kind of things I'm after.
I've seen BR-355s, and there's plenty of them out there, so thanks a lot.
Do you know anything about their wiring - which wire goes where, which color and so on?
Any advice about mounting them - how much open sky do they need, or is it OK to have them inside? The non-marine receiver I've got at the moment keeps hold of satellites from the glove box compartment, that's why I'm asking.

Thanks in advance,
Pavel
 
I have the BR555(or similar) for the gps on my netbook running Imray charts and seems to work fine once you've set it up correctly. at the moment it's just hanging above the chart table and works fine.
 
Mine works from behind my switch panel inside of the boat.

It comes with a round connector on it like the PS2 mouse connector. I didn't want to snip mine off so I bought the equivalent socket from Maplins. The connections of the connector are on the box or the leaflet. Basically it is ground, 5 Volts power, NMEA data in and NMEA data out. Connect the 0 and 5V, then NMEA data out to NMEA+ data in on your VHF, and ground to NMEA- on your VHF.

I seem to remember that out of the box it is not set up to 4800 baud. You need to install the software supplied on a CD onto a PC, connect you mouse, and change this. It's handy to run it connected to a PC first anyway to check that it's working.
 
Active antenna.

You could get a secondhand GPS such as a garmin 12/72 but you would need an interface cable. As an alternative you could connect an active gps antenna which gives a direct GPS output.
 
ithet said:
You could get a secondhand GPS such as a garmin 12/72 but you would need an interface cable. As an alternative you could connect an active gps antenna which gives a direct GPS output.
Click to expand...

You could, and I looked at doing this, but the mouse is smaller and uses less power. A mouse basically is an active GPS antenna, and although not waterproof, works inside just fine.
 
AngusMcDoon said:
You could, and I looked at doing this, but the mouse is smaller and uses less power. A mouse basically is an active GPS antenna, and although not waterproof, works inside just fine.
Click to expand...

OK, thats an active antenna then! As it has a NMEA out I agree it seems best option for OP provided he is happy to mount it inside.
 
@Angus and ithet - yep, a mouse it is then; and I would strongly prefer to keep it inside to save me drilling more holes in the deck.
I'll follow the advice WRT the plug - indeed, it's a better idea to get a female and solder it on to the radio's connector, plus to get 5V supplied from elsewhere.
Cigarette lighter - what a neat idea :) You know, I've been thinking about installing some LED lights I've spotted in TK Maxx for next to nothing, but they're battery-powered and I wanted to plug them into the main system. They're 4.5 V and I was racking my brain about how to get it down from 12V without, well, without actually doing too much. There you go then, I got my answer :) Thanks.
What was it about 4800 baud? I've checked the radio manual, there's nothing about data transfer rate requirements.

@PetiteFleur: I'm probably going off-topic here, but what's your config with the netbook? I was looking at that as an alternative to a plotter: I've got reasonable netbook and a receiver, so why pay for more hardware. Is it Imray Digital Chart you're running? Seems a bit heftily priced. I'm tempted to scan a paper portfolio and calibrate it in something like Ozi Explorer. About half the price and you get to keep the paper thing.
 
Pavel said:
What was it about 4800 baud? I've checked the radio manual, there's nothing about data transfer rate requirements.
Click to expand...

Pretty much all equipment that receives GPS data via NMEA will want it at 4800 baud, even if your manual doesn't say so. NMEA was exclusively 4800 until AIS appeared, which uses 38400 baud because of the larger amount of data to transfer.
 
Pavel said:
@Angus and ithet - yep, a mouse it is then;
Click to expand...

Good call Pavel. I would strongly recommend against taking a signal from a chart plotter, and certainly not from a HH GPS.

If the whole situation goes pear shaped, and you need to send a DSC distress, you dont want to be relying on any more electronics than necessary.

Much better to have an independant GPS receiver, powered from the same 12v supply as the VHF. If the VHF is powered up, the GPS must be, also.

It also means you dont have to fire up the chartplotter just to get rid of irritating 'loss of position' alarms on the VHF. eg at anchor or very local trips.
 
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