The Wineguard Sensar IV (the latest version from Wineguard) has been shown through testing to be the best over the air antenna available. Combined with the SensarPro (A replacement antenna amplifier); the combo is the best. If you have a Sensar antenna, add the Wingman (snap on, UHF addition, Wingman) it will make the antenna you have nearly as good as the newest Sensar IV.
Check all cable ends and connections. If you are having problems, the connections are the most likely to the cause.