The following is a Teleview , Recommendation for Digital Broadcast Tv Reception.
Above the roof install a Winegard HD7698P antenna with a KitzTech , KT-200-COAX TV Antenna Booster - Remote Power -Coax Fed preamp and antenna aimed at about 25 degree magnetic compass direction.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
For 1 Tv connected use no splitter.
For 2 Tv's connected use a , HFS-2D , 2 way splitter.
Buy the HFS splitter at ,
http://www.hollandelectronics.com , or ,
http://www.solidsignal.com.
Here are some above the roof antenna mounts ,
http://www.ronard.com/909911.html ,
http://www.ronard.com ,
http://www.ronard.com/ychim.com ,
http://www.ronard.com.
Buy the ronard antenna mounts at solidsignal by typing the word ronard in the solidsignal search box.
Here are some places to buy antennas and etc. ,
http://www.solidsignal.com ,
http://www.winegarddirect.com ,
http://www.amazon.com ,
http://www.kitztech.com.
As always , trees and tree leaves do a real fine job of reducing or blocking Tv reception and so do buildings and other obstructions.
It is best to mount the antenna in such a manner that there are little to no obstructions in the direction of reception.
The Tv/s Must Channel Scan for the Digital Broadcast Tv Channels , sometimes named the 'Air Channels' or 'Antenna Channels' in the Tv setup menu because the Tv transmissions travel through the air from the transmitting antenna to the receiving antenna.
DO NOT channel scan for cable tv channels.