Hi P2002,
I run ADSB out from a Trig TT21, so can't speak from personal experience, but there has been quite a bit of discussion about the GTX series on the forum. The general consensus is that you can't run ADSB out unless you have a GTX330ES.
If you go to the Forum 'Home' screen, enter gtx330 in the search box and you will find links to all the previous threads. (If you don't search from the Home screen you will only find any references in the specific section you are in).
Regards
Peter