A separate antenna system is for the Portland OR. Digital Tv Stations/channels.
Install a Winegard HD7696P antenna aimed at about 350 degree magnetic compass.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
For one Tv connected no amplifier or splitter is used.
For 2 Tv's connected use a CM3412 distribution amplifier.
For 3 or 4 Tv's connected use a CM3414 distribution amplifier.
The 2 Separate antenna systems will not be connect together on to one coax.
The 2 separate antenna systems will be separate all the way to the Tv locations where a remote control A/B antenna switch will be at each Tv location.
http://www.radioshack.com #15-1968 -or -
http://www.mcmelectronics.com # 32-4425