If the radio shack stuff does not do the job then you can bring out the Maximum Reach Antenna. Winegard HD8200U all channel antenna and Winegard AP8275 preamp. Point the HD8200U in the direction of 311 degree magnetic compass. The Tv channels you will be reaching out for are , WOI-DT 5 ABC , KCCI-DT 8 CBS , WHO-DT 13 NBC , KDIN-DT 11 PBS. The other stations at 311 and 312 degree magnetic compass will likley be too weak with too much adjacent channel and co-channel interference to receive. . I recommend using a Strong and Sturdy antenna mount such as a , tripod mount , chimney mount , peak of the roof eave mount. Here are places to buy antennas and etc.. ,
http://www.solidsignal.com ,
http://www.3starinc.com ,
http://www.starkelectronic.com ,
http://www.amazon.com