Linking GPS and VHF

[jlenox]

Has anyone else connected their handleld gps to a fixed mount vhf radio with dsc? I am planning on connecting my Garmin GSmap 76 handheld to a Standard Horizon fixed mount VHF. Best that I can tell by reading the manuals is that the VHF will listen to the GPS but will not talk to it because they "speak" different proprietory languages, so I can broadcast my location in an emergency but will not be able to receive others locations. Any input is appreciated. And of course, if I could afford a fixed gps chartplotter, I would buy and install it.

[sailingdog]

You can do this pretty simply... Garmin does have a wiring oddity though*.

The reason you won't be able to see the other locations is not that they speak different languages, but that the 76 GPSMap DOES NOT SUPPORT DSC call location input.

You will need to connect the GPS's NMEA OUT + to the VHF"s NMEA IN +, and then you will need to connect the VHF's NMEA IN - to the GPS's 12 VDC ground, as Garmin uses the 12 VDC Ground as their signal ground*.

You will also have to set the Garmin GPSMap 76 serial port to NMEA protocol, instead of the default Garmin protocol. You'll want to set it to 9600 baud, 8, N, 1.

I'd add that you should probably connect the 12 VDC to the Garmin's 12 VDC wire, so that you aren't relying on the Garmin's AA batteries.

[jlenox]

sdog, thanks for the info. aI will be running the wire and making connections tomorrow. Hope to post a success story!

[sailingdog]

Good luck J.

Let us know how it goes.

[CaptKermie]

A couple years ago I did exactly what SD describes above with my GPS MAP76cs handheld and Uniden 545 VHF radio with DSC. I also applied for and have an MMSI number. When they are connected the VHF radio does display the MMSI number when first turned on and does display "GPS OKAY" if all are working well. Sometimes I have to turn one of them off and on again to get them to hear each other but usually they speak right away. I have been using this for a couple years now with no problems. I cannot get other positions but the CG will certainly get mine when I press that little red button.

[jlenox]

SUCCESS! I crimped everything together today and fired up both units and my lat/lon was scrolling across the bottom of the vhf screen. Sdog, thanks for the heads up regarding changing from Garmin to NMEA, I would have been banging my head on the mast trying to figure out why it wasn't working...........!

[sailingdog]

That's why I mention it. Glad to help... The fact that Garmin uses the 12 VDC ground as their signal ground is also pretty easy to miss.

Originally Posted by jlenox

SUCCESS! I crimped everything together today and fired up both units and my lat/lon was scrolling across the bottom of the vhf screen. Sdog, thanks for the heads up regarding changing from Garmin to NMEA, I would have been banging my head on the mast trying to figure out why it wasn't working...........!