Cheap source of NMEA 0183 to feed to DSC VHF radio.

Simon F

Well-Known Member
Joined
1 Jan 2019
Messages
83
Visit site
Hi sailors,


My new (to me) boat, came with a partially fitted newish Cobra MR F57B E vhf radio which has yet to be fully commissioned (not yet entered the MMSI number and no connection for the gps data) The vhf aerial is connected, but for DSC functionality it needs a gps input. The manual specifies it should be NMEA 0183 + Data in. The chartplotter on the boat has a NMEA 2000 output only, also, it's inconveniently situated for a cable run to the radio and it outputs through some kind of , possibly proprietary multi-pin plug. I'm wondering whether, all in all, it might be easier/cheaper to donate/sell on the radio (as it hasn't yet been programmed with the MMSI number, and buy a DSC radio with gps built in, unless;

1 - There's a cost effective way to make the units compatible? Or -

2 - There's a cost effective way a to fit a simple gps unit just for the output to feed the VHF? It feels like gps is a cheap thing these days and if there's a unit with no display etc that could output NMEA 0183 it might be cheaper than replacing the radio with a unit that has built in gps.

I use a hand held radio most of the time, but I thought it might be useful to have the range and DSC capabilities of the fixed unit if I happen to sink one day.

All the best

Simon.
 
Cobra radios are the bottom of the barrel. I'd sell it and buy a Standard Horizon VHF with built in GPS. Better VHF by a mile and you won't have to spend a fortune more than you would for a GPS, taking into account what you get for the Cobra, plus you don't have the hassle of fitting the GPS.
 
Thanks, I'm starting to think you're right. It's a mystery to me why someone would buy a radio that needs a gps and install it far away from the chartplotter. I think maybe he put it in to substitute for the much better radio he took out to put on his new boat;-)
 
Thanks Dukester. Looks like it would do the job, but all in all I think it's easier and probably cheaper to swap out the radio.
 
Thanks, I'm starting to think you're right. It's a mystery to me why someone would buy a radio that needs a gps and install it far away from the chartplotter. I think maybe he put it in to substitute for the much better radio he took out to put on his new boat;-)
SH also do a VHF with GPS and AIS, just a thought if you don't have a transponder.
 
Depends how interested you are in mucking about with DIY electronics but if you're asking the question I'll guess the answer is "not very" and if that's the case, it really isn't worth mucking about to lash up some shonkey solution to save a few quid.

N2K->NMEA-0183 converters are upwards of £100. The problem with cheapo GPS units is that they tend to use 3-5V. If you're me you rip the guts out of an old phone charger and put it in a little abs box. Sensible normal people might buy a cheap 12v->5v converter form eBay. But then you've got a bunch of wires you probably don't want. What you actually want (12v powered, name out @4800 baud) seems to be thin on the ground although there seems to be one name-give-never-heard-of "marine" one that many sellers on eBay are flogging for £50. So...messy lash up: £20-£25. No-name eBay punt: £50. Convert from N2k: >£100. Budget-ish brand you've heard of like Digital Yacht: £150. in all cases you'd want to check the unit you bought output the correct sentences at a baud rate compatible with the radio.

But if you're considering swapping the radio for one with integrated GPS then that doesn't sound like a stupid plan.
 
Hi Sandy,

Yes, it's a thought. Is that what you use for AIS? I like the way you can dsc call any target on the ais screen to let them know your intentions. I'm a day sailor really, but I do have ambitions to cruise and I was considering a tablet ais overlay in Navionics using an ais receiver with a wifi network. But an all in one solution has a lot going for it.
 
You make a lot of sense Laika. If there's one thing I've grasped thus far on my boat ownership journey; it's that lash-ups using non marinised ebay stuff don't work for very long.
 
Thanks, I'm starting to think you're right. It's a mystery to me why someone would buy a radio that needs a gps and install it far away from the chartplotter. I think maybe he put it in to substitute for the much better radio he took out to put on his new boat;-)
Its a mystery why some folk think they are capable touching electric or electronics. Much of my work in getting our various boats ready for use has been stripping out rubbish or at least finding out what it does or where it goes. And there is also no limit to stingey sellers stripping things before sale.

The advantage of inbuilt gps in radio is that it enables one to turn chart plotter or other separate device off, thus saving battery life if under sail. Not relevant if a mobo however, but it also reduces risk from the often vulnerable NMEA connections between the units failing.

Me, I would go for radio with gps and AIS. I know it costs more but there is simple benefit in seeing where bigs ships are is certainly useful if near ports or shipping lanes.

I like standard horizon but there are others
 
I had a similar problem but with a better radio on my old boat. I sourced an 0183 nmea smart gps mushroom for less than £40. I suspect if you look on ebay you could get one for a similar price. It also means you don't need to have your cp powered up. Unless you have a steel boat you can usually mount it inside alongside the radio unit and it will still give you a good fix


Marine Ship GPS Receiver Antenna Module NMEA 0183 Baud Rate 4800 DIY Connector | eBay

Gone up a bit!
 
Last edited:
I had a similar problem but with a better radio on my old boat. I sourced an 0183 nmea smart gps mushroom for less than £40. I suspect if you look on ebay you could get one for a similar price. It also means you don't need to have your cp powered up. Unless you have a steel boat you can usually mount it inside alongside the radio unit and it will still give you a good fix


Marine Ship GPS Receiver Antenna Module NMEA 0183 Baud Rate 4800 DIY Connector | eBay

Gone up a bit!


Thanks TSB, that's very interesting. And it looks really easy to fit. As you say, fine in the cabin and anyway probably better not to expose it to the elements. SF
 
I had a similar problem when the gps feeding our Icom DSC failed, cost £170 for local dealer to supply and fit a gps internally under a headlining to it. I looked at buying a newer Icom radio with built in gps but it would not take my existing RAM mic and would end up much more expensive overall.
 
Hi Sandy,

Yes, it's a thought. Is that what you use for AIS? I like the way you can dsc call any target on the ais screen to let them know your intentions. I'm a day sailor really, but I do have ambitions to cruise and I was considering a tablet ais overlay in Navionics using an ais receiver with a wifi network. But an all in one solution has a lot going for it.
It is one way of getting to transpond AIS signals cheaply if you were to upgrade to a SH with GPS then take a look at the unit with AIS. You will need to do some research about linking it to a tablet.

My AIS unit lives below at the nav station and was ignored until last summer when I wired it up to the chartplotter. I transmitted for years as it tells the CG what I've been up to should I ever need to hit the wee red MAYDAY switch, tells family and friends where I am on my wee adventures, and lets everybody at the sailing club know if I'm going to get back before last orders.

Wiring AIS up to the chartplotter was interesting as it showed that the big ships really do follow COLREGS. One Manhattan (MMSI 431260000) overtook me in a narrow channel in the Thames estuary and she is much bigger than me. I was passed by Eendracht (MMSI 244543000) the North Sea. Having the AIS displayed in the cockpit allowed me to look stuff up on long passages. Just wish pot markers would transmit on AIS!
 
I have never called up the ships shown on my AIS, but the display shown the radio shows approx position relative to me, then if I ask details gives their speed over the ground, closest approach time and distance.

If they are moving at 18kts and closest approach is 100m in ten minutes and nothing changes at 5 minutes then I think I better get out of the way. Likewise if they are actually stationary in my path. All particularly useful in poor visibility or night. It would have avoided a nasty shock we had with earlier boat when we did not understand that the clutter of lights ahead and beam onto us was not a boat going down tide as was usual on falling tides in the Bristol Channel, but a large dredger whose work lights had masked the red white red, and was firmly anchored collecting sand mid channel right in our route.

If you are mostly bay sailing out of the shipping lanes then you wont need it, but if you aspire to longer coastal passages in that boat it might come in useful eventually.

However the availability of that GPS dome might get you sorted with current kit. I dont much like buying from China due to poor quality control but its not mega bucks if it proves unreliable
 
Top