My Garmin GNS 430 came back from its WAAS upgrade on Friday, making it a GNS 430W. I reinstalled it this weekend.

The upgrade also included a new Terrain display, with warnings about terrain that is too close below, or high terrain that is within 60 seconds flying time ahead. It isn't quite a Transport Category Terrain Avoidance Warning System, but it is pretty good, all in all.

The GNS 430W needs a new antenna, and I was disappointed to see that the new one, although it had the same mounting screw spacing, was wider and longer than the old one. That meant that the spacer I had made to fit between the curved fuselage and the flat antenna bottom was too small. It was a pain in the you know what to make the first spacer, and I didn't want to to invest the time now to make a new one.

The new GA-35 antenna is on the left, the old one in the middle, and the spacer for the old one on the right.

I made some little tapered UHMW plastic spacers to go go over the two outboard screws for now. I'll make a proper spacer sometime after I get flying.

Looking at the Installation Manual for the GNS 430W, it seems that there are several different antennae that could be used. One of them, the A34, supposedly has the same footprint as my original GA 56 antenna. I should have done this research earlier, and specified a requirement for the A34 antenna. I'll call the avionics dealer I use, and see if I can return the GA 35 antenna, and get an A34. That is a more interesting option than making a new spacer.