Because of the trees in the directions of reception.
And your location has receivable Digital Broadcast Tv stations/channels in all three Tv channel bands.
The current Tv channel bands of , USA , Canada , Mexico , are.
VHF low band channels 2 thru 6.
VHF high band channels 7 thru 13.
UHF band channels 14 thru 51.
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Install above the Peak of the Roof in such a manner that the roof and house are not blocking reception to the north east and south west.
Install a Winegard HD7084P all channel 2 thru 51 channels antenna aimed to the north east at about 38 degree magnetic compass direction.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
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The HD7084P antenna is smaller then the HD8200U antenna.
The HD7084P is 9 feet long.
The HD7696P antenna that is designed for reception of channels 7 thru 51, and is 9 feet long.
The HD7694P is to small for good reception at your location and is designed for reception of channels 7 thru 51.
THE HD7697P and HD7698P are both longer then 9 feet and are also designed for reception of channels 7 thru 51.
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Here are some strong and sturdy antenna mounts.
http://www.ronard.com/909911.html. Use the 5 foot tripod antenna mount.
http://www.ronard.com/34424560.html. Use the #4560 eave antenna mount.
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 or buy from ronard.
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Here are some places to buy antennas and etc. .
http://www.solidsignal.com.
http://www.amazon.com.
http://www.winegarddirect.com.
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Install a Winegard HDP-269 preamp.
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For 1 Tv connected use No splitter.
For 2 Tv's connected use a , HFS-2D , 2 way splitter.
For 3 Tv's connected use a , HFS-3D , 3 way splitter.
Buy the HFS splitters at ,
http://www.solidsignal.com , or ,
http://www.hollandelectronics.com.
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As always , trees and tree leaves , plants and plant leaves , have a negative effect on reception , multi-path/reflections , absorbing , blocking , Broadcast Tv reception and so do buildings including your own roof and house and other obstructions.
The best practice is to install the HD7084P 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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The Tv's Must Channel Scan for the , OTA=Over The Air , Digital Broadcast Tv stations 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.
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'.
Scan for channels.
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