The following is a Teleview recommendation for broadcast Tv reception.
No less the 25 feet above ground , install a Antennas Direct DB4e antenna aimed at about 120 degree magnetic compass direction.
Here is how to aim antenna ,
http://www.kyes.com/antenna/pointing/pointing.html.
And install a Antenna Craft CS600 aimed at about 95 degree magnetic compass direction.
Connect the 2 antennas together with a UVSJ = UHF/VHF Separator/Joiner.
Type these letters -> uvsj , in the ,
http://www.solidsignal.com , search box.
For 1 Tv connected use no splitter , use no amplifier.
For 2 Tv's connected use a Channel Master CM3412 distribution amplifier.
For 3 or 4 Tv's connected use a CM3414 distribution amplifier.
Here are some above the roof antenna mounts ,
http://www.ronard.com/909911.html ,
http://www.ronard.com/Tripods%200703/4712.html ,
http://www.ronard.com/34424560.html ,
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.amazon.com ,
http://www.antennacraft.net.
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 install the antennas at a location that has the least amount to no amount of obstructions of any type or kind in the directions of reception.
The Tv/s Must Channel Scan for the Digital Broadcas Tv Channels , sometimes named the 'Air Channel' 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.