Use a - Plain Old School Compass - for antenna aiming.
Do Not connect the Tv antenna or coax from the Tv antenna or the amplifier or any other part of the Tv antenna system to the pay cable service system.
The Tv antenna and etc. Must Not Be connected to the pay cable service , Not cable Tv , Not internet cable , Not telephone cable service.
The antenna system and cable system Are Not connected together on to one coax in any shape or forum.
The antenna system is a separate system.
The cable service is a separate system.
Yes you can use the coaxes that are in or on the house for the antenna system , however the coaxes used for the antenna system Can Not be connected to the cable system.
And coaxes that are used for the cable system Can Not be connected to the antenna system.
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To prove reception with the antenna , eliminate problems , Run a New coax from the antenna -->directly to 1 Tv. No couplers , No grounding block couplers , No splitters , No electronic devices.
Scan for Digital Broadcast Tv stations/channels.
Digital Broadcast Tv Tuners can develop - Digital Glitches - that are not cleared out with simple channel scans.
Do a Double Rescan ,
http://www.dtv.gov/rescan.html.
Check reception.
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Now connect the , preamplifier , power inserter , power supply , and Scan for Channels.