Steve
I know you have mentioned this before but it never clicked, I still have the rubber ducky antenna sticking up on the dash, assume I can remove this as the unit is hard wired to the 796.
Figs
For Gizmos
The issue is that for ADSB
out a certified WAAS gps is required, neither the GDL39 or the 796 have a certified gps. In my case the 796 works fine on the internal antenna so I did not install the external one and based on Steve's comment I can remove the GDL39 antenna so the only external gps antenna I will have is the GPS antenna that come with the GDL82