Install a Winegard HD7082P antenna above the fence post aimed at about 180 degree magnetic compass.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
A much better place to mount the antenna is above the roof.
Here are some roof top antenna mounts ,
http://www.ronard.com/909911.html ,
http://www.ronard.com/34424560.html ,
http://www.ronard.com/ychim.html ,
http://www.ronard.com.
Buy the antenna mounts at solidsignal by typing the word ronard in the solidsignal search box or buy from ronard.
http://www.solidsignal.com ,
http://www.winegarddirect.com ,
http://www.amazon.com
Here are light weight lay over aluminum antenna towers , install antennas and make adjustments standing on the ground.
http://www.palcoelectronics.com