Attics are not friendly environments for Tv reception , multipath is the reason (reflected signals). Are there any large trees close that can be blockig reception?? Any big buildings close the can be blocking or creating bad multipath. Do not connect a amplifier , it will make the reception worse because the amplifier will amplify the reflected signals. Are there any airports around ?? Reflected signals off of planes are multipath. You can try this multipath/ghost reducing antenna in the attic ,
http://www.solidsignal.com/prod_disp...p?prod=ANWGHST . I am thinking that a Tv antenna will need to go to the outside of the roof.