Read and understand this about , Real Digital Tv Channels , Virtual Digital Tv Channels , Analog Tv Channels ,
http://forum.tvfool.com/showthread.php?t=695 , Here is how to point Tv antennas ,
http://www.kyes.com/antenna/pointing/pointing.html . I suggest a VHF High 7 thru 13 , UHF 14 thru 69 antenna , the Winegard Hd7697P antenna , to receive WBBM-TV -- Real channel 12 CBS and WLS -TV -- Real channel 7 ABC. Direct the antenna at about 80 degree magnetic compass. Here are some Strong and Strudy Tv antenna mounts , tripod antenna mount , chimney antenna mount , peak of the roof eave mount. Here are olaces to buy Tv antennas and etc.. ,
http://3starinc.com ,
http://solidsignal.com ,
http://www.starkelectronic.com ,
http://www.amazon.com