Guest, my comment about the range was a joke. Range figures in general are BS (Brittany Spears) garbage. There's no way the RCA flat antenna is any better than the Mohu or the Winegard. Those flat antennas have very limited gain. In fact, lower gain than the old fashioned rabbit ear / loop combo that used to be very popular. However, they can work well for people who need to get an antenna flat up against a window.
KTUL is the lowest frequency in your lineup, and the lower the frequency, the less a small, flat antenna can do for you. It's that simple. The two suggestions from dkr: "a roof mount like a RCA ANT751R or an Antennas Direct C2-V" were excellent.
Rick