Garmin echomap settings?

[wingcommander]

OK, quick version. Original Raymarine a50 sends info via NMEA 0183 to clipper speed display works fine . New Garmin echomap fitted , wire nmea out to same connection junction, gps position on vhf displayed as expected. Now speed display anomaly ( shows speed however its 10 x ie 30knots instead of 3) . Turn on Raymarine so both gps operating, still wrong speed . Turn off new Garmin bingo! speed now correct again .
Do I need to push a few buttons on the Garmin , or reef earlier if using this .

Cheers

 

[PaulRainbow]

First thing i would try is disconnecting the a50 NMEA connection.

Then, does page 12 here help: https://www.nasamarine.com/wp-content/uploads/2015/12/Clipper-Log.pdf

Avoid having two data sources to any device. If you want the Garmin and a50 on at the same time, don't have both outputting GPS data, for instance.

 

[wingcommander]

Thank for the fast reply Paul . I didn't have the old A50 switched on after the Garmin install. Just instantly a multiple of 10on the clipper display. It was only after reverting back i noticed the correct speed. Thus assuming something on my garmin is outputting differently.

 

[PaulRainbow]

Thank for the fast reply Paul . I didn't have the old A50 switched on after the Garmin install. Just instantly a multiple of 10on the clipper display. It was only after reverting back i noticed the correct speed. Thus assuming something on my garmin is outputting differently.

OK, if you're not going to use them at the same time, disconnect the a50 NMEA out and if that doesn't fix it, try page 12 in the NASA manual. I'm not aware of anything you should need to change in the Echomap settings.