Looking at my “nearby”, I see one with outstanding performance, and several with very similar performance. The polar view is even the same, indicating that traffic patterns have some impact on coverage numbers.
I would be inclined to build a spider. I have built a few over the years, for different radios.
There aren’t any parts stores here, like there were down in the Silicon Valley ;-(
My best with the little antenna is no ground plane, sitting on a metal arm touching the skylight.
The 170mm pan seemed to hurt.
Today, I think I’ll try a spider, using the existing base, and some 67 mm pieces of 12AWG copper house wire.
FlightAware conveniently sent me a welcome letter with a shopping list
5 meter cable
I might just put the FlightAware antenna on my Christmas list, and mount it on the outside of the skylight housing, if Santa brings it to me.