External GPS for RDP149 VX2

[Jrspawn]

Hello, I’m trying to figure out which external gps I can run with the rdp149? I already have a Lowrance external gps on the boat that looks like it has a 4 pin connector. Can this be used with some sort of an adapter?

Thank you!

 

[Jrspawn]

And my next question would be, could I use my standard horizon 1850G vhf to supply the rdp149 with a gps signal? Or even my lowrance elite Ti unit?

Thank you

 

[Johnny Electron]

As long as the source is NMEA 0183 at RS422 signal level any of those would work. If one of those is RS232 then it would need a RS232 to RS422 converter.

 

[Jrspawn]

So I ended up using the gps output from my gx1850g vhf... but not getting any position on the rdp149 still. Going into data port 2 using the yellow and green wires(pin 3 and 4). I went into the nav settings and changed the source to “all”. Is there anything else I am missing or need to do to get it to work? Thank you!

 

[Johnny Electron]

Some of those radios use a higher baud rate of 38,400. I would recommend first verifying you have data coming in showing up on the Vx2 port monitor. If you look at the port monitor for data 2 it should show you the data coming in. If the data looks like hieroglyphics then it is most likely at a different baud rate. You should change the baud rate of data 2 to match what you have wired in. Once received and matched, your port monitor should show the NMEA 0183 sentences coming in clearly.