Never buy the 1,000,000 mile spaceship antennas. They are cheap flimsy junk. Antenna web is Very conservative reception predictions. Tvfool is the most accurate for real world reception. In what direction is the antenna in the attic pointing?? Is the antenna in the attic a all band UHF/VHF Tv antenna?? Here is how to point Tv antennas ,
http://www.kyes.com/antenna/pointing/pointing.html .. .. How many Tv's will be connected??