The digital Tv transmissions are VERY STRONG at your location. A amplified antenna of any type or kind will make the reception worse , the HDTVa amplifier antenna will overload from the VERY STRONG Tv transmissions and make the reception worse. The SDV2210/27 indoor antenna has that , so called fine tuning 12 position switch , it's near impossible to find a switch position that works with all channels , more trouble then it's worth. You can try putting the SDV2210/27 outside on the ,north , north east side of the garage , put the SDV2210/27 up high if you can so the reception will not be influnced by close buildings and etc. . The strong main signals and the strong reflected signals from buildings and mountains are disrupting reception. Start with aiming the SDV2210/27 antenna at about 15 degree magnetic compass , here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html , and turn the antenna to find the best reception.