Cobra F55 VHF and GPS interfacing

Alpha22

Alpha22

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I have just been given a Cobra F55 VHF. It is the bog standard Cobra DSC radio. The cable to connect it to my GPS to get the Lat and Long is missing.
I have searched the web to no avail..... does anyone know the pinout??? It appears to be a small headphone size jack on the rear of the radio.... no idea if it is mono or stereo. The manual talks of 2 wires....???

All help appreciated...
 
You need a 2.5mm mono jack - couple of quid on eBay. Just make sure you get a straight rather than cranked version and get the slimmest one you can find or it won't fit into the recess on the vhf

Not too many with bare leads available so just hack of the other plug it comes with if you get a 2.5 to 3.5 lead for example
 
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As Chaktoura says you need a 2.5 mm mono jack, ebay or maplin. The F55 has two jack ports on the back, a 2.5 mm for the GPS interface and a 3.5 mm for the external speaker extension. Beware of the manual, in mine at least the two ports are labelled the wrong way round and this had caused the previous owner to wire them up backward so neither the interface nor cockpit speaker worked! You need to attach the jack (ebay or maybe maplin) to a bit of 2-core cable for the red and black NMEA leads. I guess the black should be soldered to the jack earth but somebody more familiar with NMEA can probably advise on that.

It is impossible to find the Cobra interface lead on the web but you may have some luck if you try your local marine engineers. Mine were able to get the original cable from Cobra, saying something about it only being available to trade, about this time last year. It cost 8 quid. But the job is simple enough to do yourself.

Cheers
 
As an aside, I found mine would not work with the version pf NMEA 183 put out by my older GPS. I've had to buy a modern GPS to get the positional data to the radio.
 
Topcat47 said:
As an aside, I found mine would not work with the version pf NMEA 183 put out by my older GPS. I've had to buy a modern GPS to get the positional data to the radio.
Click to expand...


That's a bit of a worry as I am hooking it up to my current vintage Yeoman and Garmin GPS 72 (old version)

I'll get a cheap mono lead and give it a go. - If that fails SWMBO can buy me a nice new plotter for my birthday!!!
 
Alpha22 said:
That's a bit of a worry as I am hooking it up to my current vintage Yeoman and Garmin GPS 72 (old version)

I'll get a cheap mono lead and give it a go. - If that fails SWMBO can buy me a nice new plotter for my birthday!!!
Click to expand...

I'm no nmea expert but the garmin 72 uses version 2.3 data which is the same as my garmin 152 so hopefully you'll be Ok
 
Topcat47 said:
If not, a cheap HH GPS will give you the output in a more modern version, you don't actually need a new plotter.
Click to expand...

...and an even cheaper BR355 GPS "mouse" will do the same, use less power, and if you wire it to the radio power circuit the whole thing will be self-contained.

On the Scuttlebutt Poole trip the other month, all my instruments on the new boat were in disarray except for the newly installed VHF. I lashed up a power feed to the depth sounder to get that working, and we then navigated by the lat/long readout on the front of the radio, being the only GPS on board.

(Well, ok, it was only Southampton to Poole, so we mostly navigated by eye :) )

Pete
 
Well..... I got the cheap mono cable from eBay. Striped the ends and stuck them in the chocolate block that connects the GPS to the Yeoman and within seconds the Lat and Long were displayed on the radio. Bingo - 50% chance of getting it right and I did!! Well chuffed.
 
Hello everyone, i am sorry for reviving this old thread, but wonder if someone can assist me. I've had a cobra mr f55 eu radio since 2005. It has dsc and i would like to hook a gps device to it so it can display position. Will one of the gps modules for sale on ebay work? My cobra came with a phono plug with a black and a red wire attached to the plug. I admit to being completely useless with modern technology, so any help is very much appreciated. Best regards, Oz.
 
oz-1 said:
Hello everyone, i am sorry for reviving this old thread, but wonder if someone can assist me. I've had a cobra mr f55 eu radio since 2005. It has dsc and i would like to hook a gps device to it so it can display position. Will one of the gps modules for sale on ebay work? My cobra came with a phono plug with a black and a red wire attached to the plug. I admit to being completely useless with modern technology, so any help is very much appreciated. Best regards, Oz.
Click to expand...

Its easy to do ....

The 2mm mono jack plug ---- NOT 2.5mm as early posts state as you see has two wires ... the red is centre pin and the NMEA IN ... the black is outer part of plug and is the GROUND

You need a GPS that outputs NMEA 0183 .... plenty of pucks / modules do this. For a Module such as Beltian - you need connect :

Red V to +5V supply from a BEC DC-DC reducer.
Black GND to the negative of the DC-DC reducer
NMEA Tx will then go to VHF plug red wire.
The GND of the VHF plug is then connected to the negative of the DC-DC reducer to complete the NMEA circuit.

DC-DC reducer other two wires then connect to the + and - leads that power the VHF .... this gives GND commonality.

But question : Do you have a GPS unit / plotter on board ? Why not use that to supply the NMEA data ? Then there is no need to have a DC-DC reducer etc.
 
Hi Refueler, and thanks for your prompt reply. Apart from a depth sounder and the radio, i don't have any electronic devices on my boat. The gps modules advertised on ebay are cheap, so i will buy one and try it. Best regards, Oz.
 
Refueler said:
Its easy to do ....

The 2mm mono jack plug ---- NOT 2.5mm as early posts state as you see has two wires ... the red is centre pin and the NMEA IN ... the black is outer part of plug and is the GROUND

You need a GPS that outputs NMEA 0183 .... plenty of pucks / modules do this. For a Module such as Beltian - you need connect :

Red V to +5V supply from a BEC DC-DC reducer.
Black GND to the negative of the DC-DC reducer
NMEA Tx will then go to VHF plug red wire.
The GND of the VHF plug is then connected to the negative of the DC-DC reducer to complete the NMEA circuit.

DC-DC reducer other two wires then connect to the + and - leads that power the VHF .... this gives GND commonality.

But question : Do you have a GPS unit / plotter on board ? Why not use that to supply the NMEA data ? Then there is no need to have a DC-DC reducer etc.
Click to expand...
You need a 2.5mm jack which is presumably what he already has provided he's not referring to the 3.5mm jack used for an external speaker. See below
Connecting a non-Cobra GPS Device to the MR F45 / 55 / 75
 
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Refueler said:
Its easy to do ....

The 2mm mono jack plug ---- NOT 2.5mm as early posts state as you see has two wires ... the red is centre pin and the NMEA IN ... the black is outer part of plug and is the GROUND

You need a GPS that outputs NMEA 0183 .... plenty of pucks / modules do this. For a Module such as Beltian - you need connect :

Red V to +5V supply from a BEC DC-DC reducer.
Black GND to the negative of the DC-DC reducer
NMEA Tx will then go to VHF plug red wire.
The GND of the VHF plug is then connected to the negative of the DC-DC reducer to complete the NMEA circuit.

DC-DC reducer other two wires then connect to the + and - leads that power the VHF .... this gives GND commonality.

But question : Do you have a GPS unit / plotter on board ? Why not use that to supply the NMEA data ? Then there is no need to have a DC-DC reducer etc.
Click to expand...
Just came across this thread from 2023.
What Beitian GPS module would you recommend for the job nowadays?
Anything specific to look out for and is just the module needed or should it be in some sort of case?
Does the module have to be positioned anywhere specific, i.e. outside, or can it be kept inside the cabin?
As you can see from the plethora of questions, I find this confusing but would like to add GPS functionality to my Cobra MR F55 EU marine VHF radio, but don't know how to best go about it. Thanks for any advice available.
 
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