Above the roof install a Winegard HD7082P antenna aimed at about 230 degree magnetic compass direction.
It is best to install the antenna in such a manner that roof or house is not blocking reception in the directions of reception , south west , west , north west , north east , south east.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
No preamplifier is required.
For 1 Tv connected use no splitter.
For 2 Tv's connected use a common simple 2 way splitter.
For 3 or 4 Tv's connected use a Channel Master CM3414 distribution amplifier.
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Here are some strong and sturdy 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 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.winegarddirect.com ,
http://www.channelmasterstore.com.
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As always , trees and tree leaves do a real fine job of reducing or blocking Tv reception and so do buildings and other obstructions including your own house.
It is best to install the HD7082P antenna at a location that has the least amount to no amount of obstructions of any type or kind in the directions of reception including your own house.
The reception directions are , south west , west , north west , north east , south east.
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.