I have a GTN 650, GTX 327 mode C transponder, and GDL 88 for ADS-B. The GTN 650 is configured to control a transponder via a button on the right side panel of the map page. This is great for a GTX 33 remote xpdr, but to me it is unnecessarily redundant as my GTX 327 is two inches below the GPS and I interact with the xpdr directly. I assume there’s a necessary interface between the 650, 327 and GDL 88 for ADS-B purposes, but I’m wondering if there’s a way to deactivate the xpdr control button in the GTN configuration (and replace the space with a user-chosen field, for example) without messing with the critical interface underlying it all. As I recall, the xpdr control came in with a later version of the GTN software and wasn’t originally there. I forget what was in that space originally, but I remember disliking the change. I thought I saw a vague mention of this in a forum somewhere but I can’t find it now.
