Indoor Tv reception is Not a reception friendly environment and Never Will Be a reception friendly environment.
Signal attenuation and (multipath) reflected signals bouncing all around is not reception friendly.
For a indoor type antenna use Terk HDTVi (not the HDTVa) , aim the HDTVi antenna at about 90 degree magnetic compass direction. East.
Here is how to aim indoor antennas and outdoor antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
To improve the reception put the HDTVi antenna in/at a window or patio/balcony window that is to the east.
If the Tv is not close to the HDTVi that in/at the window then run a loooong coax from the HDTVi to the tv.
The Tv Must Channel Scan for the Digital Broadcast Tv Channels , often 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.
Go into the Tv setup menu and select , 'Air Channels' or 'Antenna Channels'.
Some Digital Tv's will automatic channel scan for cable tv channels.
DO NOT channel scan for cable tv channels.
Go into the Tv setup menu and select , 'Air Channels' / 'Antenna Channels'.
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Attics Are Not a reception friendly environment and Never Will Be a reception friendly environment. Signal attenuation and (multipath) reflected signals bouncing all around is not reception friendly.
For a antenna installed in the attic , install a Winegard HD7000R antenna aimed at about 90 degree magnetic compass direction. East.
No preamplifier is required.
For 1 Tv connected use no splitter.
For 2 Tv's connected use a simple common 2 way splitter.
For 3 Tv's connected use a simple common 3 way splitter.
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As always , trees and tree leaves do a good job of , reflecting , reducing , blocking Tv reception and so do buildings and other obstructions including your own roof and house.
It is best install the HD7000R 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 roof and house.
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Here are some places to buy antennas and etc. ,
http://www.solidsignal.com.
http://www.amazon.com.