I'm using the Antenna kit available from Airnav, which uses a Wimo GP-1090 antenna and Mast pre-amplifier AS-1090. Antenna and pre-amp are mounted in the loft.
Not on a mountain, no. I'm at 90ft ASL, right on the coast, but get pretty good coverage where I'm not blocked by mountains or other houses. Antenna is positions so as to get best coverage on the route up from England to Inverness.