I currently have a piece of crap TERK TV55 antenna like below mounted on the north side of my house. It does an ok job, but I lose the signal sometimes based on my distance and its design and reception pattern.
I'm thinking about getting one of these from Winegard, it has very good ratings and upto 40 miles reception. All the towers are exactly due north of my home up in Ankeny (about 25 miles). This antenna is more directional than the Terk. Midstated Distributing here in Des Moines carries them for under $100.
