Usually as you look at the rear of the Wall plate
With the 12 volt leads at the top
And the cables at the bottom
Antenna (OTA rooftop) Park Cable TV 2 (Tv 1 is the front connection)
Many people call that wall plate the amplifer.. NO IT IS NOT. it is the Power inserter and source switch. Unless you have a Sensar Pro (you do not. the pro has 4 connections on the rear and none on the front) it's not an amplifer. the amplifer is in the antenna itself.. This box just provides the power to it (Why it has the 12 volt leads.
NOTE: Replacing it with a Sensar pro (The leads are labeled) GOOD IDEA.