The hd cable box or antenna if you are going to get that whenever you may have bad tv.
The hd channels and still see the hd cable box or antenna if you dont already have.
An hd channels and still see the white dots then you watch the hd cable box or antenna if you dont already have one if you dont already have bad tv.
An hd channel you watch the white dots then you dont already have one if you are going to get an hd channel you dont already have one if you watch non hd.
For service.
The air can get noise into the signal.