Have you considered installing an outdoor antenna on a simple pole mount attached to the side of the house? I think this would probably be the only way to get good results with an OTA antenna at your house, with its tile/stone roof. I did this many years ago, with the pole attached to the side of my chimney, and it's working extremely well for me. I had tried an attic mount first, but the signal levels were terrible. Simply moving the antenna outside—just sitting haphazardly on the roof at first, as a test—dramatically improved the reception quality. IMHO, just figure out the easiest, cheapest way to get an antenna outside the house. The higher the better, but "outside" is the key.