garmin 126 to Neptune 100 dsc radio

[Amulet]

I had understood that the garmin would send coords to the radio.
The garmin diagram shows the NMEA wires blue out brown in.
The radio just offers a yellow and a green NMEA lead.
I Have tried these both ways and just get a message on the radio ' no position' but the garmin is showing the correct coords.
The garmin info suggests that ther are 3 NMEA options 0180 0182 and 0183
has anyone any experience with this set up or who can offer any advice ??
many thanks

The NMEA "in" and "out" are relative to ground. You are sending NMEA to the Radio, not receiving it from the radio. I'd expect you to have to connect the NMEA "out" of the Garmin to the NMEA "in" of the radio, and the ground (-ve) of the Garmin to the ground of the radio. I don't think it matters a monkey's where the NMEA "in" of the Garmin goes 'cos the radio ain't going to send anything (but I might be wrong on this). Either one of your two wires of the radio is ground rather than NMEA "out", or else you need to find a way of connecting the two grounds. I'll eat my hat of it's anything but NMEA 183, and it'll set itself to 4800 baud without any futzing about.

Finally, your Garmin GPS may send the "Garmin protocol" by default. It will be possible to set it NMEA - in my Garmin experience in some "system setup" submenu called "interface" - this is probably where your 180,182,183 options are too.

 

[pcatterall]

Many thanks guys, it seems that it may just be that I should try NMEA/NMEA rather than the RTCM/NMEA that I had switched it to.
It seems a bit of a chore but as you say once you know the system it will only be a few seconds to change over!!
Many thanks for your efforts!!