I think the powered amp is a signal strength enhancer. We had one in the back of the slideout in the bus and on the Holiday it located on the wall as a switch .
I think that if your tv was made in the present millenium its probably digital but may not be HDTV . SO, id check your tv model on the internet and see its specs and then (anyway) go over to Campers world or RV World and see what they have to connect to your Winegard (EVEN THOUGH I HATE the WINEGARD and like the PHILIPS better).
We can get HDTV right from the air but the onliest problem is that the fuckin thing would get all pixillated whenever some truck or car drove by. WE NEVER PARK ON WALMART LOTS cause all the traffic drives the thibg crazy. The Philips signal amp did a wonder at improving that condition.
ANOTHER way to know what kind of tv you have, whenever theres interference do you get a snowy picture or does it pixillate? Pixillation means its digital and snow means its the old analog.
I got my last portable ( 13"flat panel tv for the trailer bedroom) at an auction and payed 35$ . Hows zat fer smart buying? Lots a people got these flat panels as a comon from their banks or Costco, and then wanted bigger screens. 13" is just perfect fopr our trailer bedroom