Is structure the antenna is in a , house , condo , apt. , mobile home , motor home ? Is the antenna in a basement ? Is the structure wrapped with any type or kind of metal such as but not limited to metal siding or stucko with stucko Wire. Does the building have a metal roof ? Is the antenna at a place that blocks reception ? Is the Tv set to Scan for Broadcast Digital Channels ? Not analog or cable channels.
http://www.kyes.com/antenna/pointing/pointing.html