Whatever antenna you are using, is inadequate to pick up the signal.
http://www.antennaweb.org/aw/welcome.aspx
You have said nothing about the antenna you have so I can't be more specific than this, but you need to check the website above.
An outdoor antenna that can be aimed to maximize the signal is always going to be the best antenna choice, but this site can help tell you how good of an antenna you need to get this station from your location. It will take some studying though on your part to understand correctly what it is telling you.
