I worked on my G3X system diagram today so I can start locating the required avionics.
I'm not sure yet if I'm going to get a G5, but I left it in the diagram for now.
I bought a used GTX 327 which I will couple with a GDL 82 ADS-b out.
I have two GMU 11 magnetometers (by accident), but I will use them both in the tail cone. I've read that having two of them can cancel out errors induced by nearby motors or high current (100mA) wires.
