As I stated before , and will now expand on.
The Tv Must Channel Scan for the Digital Broadcast Tv Channels.
The Tv tuner Must Be a Digital Broadcast Tv tuner , also known as a ATSC tuner.
DO NOT channel scan for (QAM) cable tv channels.
And also DO NOT channel scan for Analog broadcast Tv channels , by them selfs.
The Tv tuner in the Tv Must Be a Digital Broadcast Tv tuner , also known as a ATSC tuner.
Often named the 'Air Channels' / 'Antenna Channels' in the Tv setup menu.
-->If<-- the Tv does not have a Digital Broadcast Tv tuner also known as a ATSC tuner then a Converter Box must be used to receive the Digital Broadcast Tv channels.
Here are some converter boxes.
http://www.epvision.com.
http://www.channelmasterstore.com.
Also I recommend the antenna setup I recommended.
And as I also stated , All satellite system hardware must be removed , multi switches , diplexers , splitters , amplifiers , power supplies , power injectors , and etc..
If there is any cable tv system wardware from the past , that must be removed.
Yes it it Ok to use the coaxes that are in or on the house , for the antenna system.
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As a Test , to prove reception , connect a New looooong coax to the antenna and run the New looooong coax from the antenna through a open door or open window , direct to the Tv , No splitters , No couplers , No ground block , No amplifier , No nothing.
Scan for Digital Broadcast Tv channels.
What is reception like now??