When I visit that address, all I can find are pages of links to sellers. I can't find a link to an antenna selection page. Does that site still offer a reception analysis function?
I thought it was maintained by some big-time industry trade group, so it is hard to imagine that they might have inadvertently let their ownership/control of it lapse.
Well, I entered it yesterday as .org (checked my browser history) and definitely got the "wrong" website, same as you described. It was different than the ".com" site that loads this morning.
There was definitely something screwy going on yesterday over there... I don't think you were imagining things or mis-typed the web address.