If you don't want to replace the antenna on your roof, just get one of these and plug it in the back of your television. You can always stick it out the window too.
click hereWall Mart, Best Buy, any electronics store sells them, actually, you can find them pretty much anywhere now. There was the As-Seen-On-TV ad that sold them too. We have 4 of these in the house, since we have DISH satellite, and just flip the "input" on the television when we want to watch over-the-air. They work pretty good. But also found each television works different on the same antenna. It's like the newer the television, the better they work (pull in more stations), for the same antenna.