It is Ok to use 1 antenna , a Winegard HD7694P point the antenna at about 58 degrees magnetic compass . Here is how to point Tv antennas ,
http://www.kyes.com/antenna/pointing/pointing.html . Antennas Direct does not sell a All Channel Antenna , thats why they sell people 2 antennas. Also read and understand this about Real Digital Tv Channels and Virtual Digital Tv Channels ,
http://forum.tvfool.com/showthread.php?t=695