Jay Maynard wrote:
As my .signature attests, I'm also a ham radio operator. I'd like to be able
to use a 2 meter/440 MHz dual-band radio in the aircraft. While, ideally,
that radio would be an Icom IC-2820H, like the one in my car, practically
speaking it'll be a handheld. An external antenna would seem to be a useful
thing, with the cable brought forward to some convenient spot so I can hook
the radio up to it.

What are other hams doing in their aircraft?

I'm going to be trying APRS in my plane,
but that's at least a couple months off.