If the roof is not , metal roof , does not have metal backed insulation , does not have solar panels. Then I recommend a Antennacraft U4000 antenna aimed at about 230 degree magnetic compass. Here is how to aim antennas ,
http://www.kyes.com/antenna /pointing/pointing.html. WUPV-DT real digital channel 47 will be received through the back side of U4000. It's best to mount the antenna as high as possible in the attic and keep the antenna away from ducting and heating/air conditioning if there is any in the attic. Large metal objects can effect the reception mostly in a negative way so mount the antenna away from large metal objects. If a brick or metal chimney goes up through attic mount the U4000 so the chimney does not block reception of the front or back side of the U4000.