The Tv stations are all UHF in the direction of about 121/128 degree magnetic compass from Leavenworth Kansas. I recommend a Antennas Direct DB8 UHF antenna. Can you move the antenna and shoot around the Walnut tree? If not , then put the DB8 on the other side of the Walnut tree toward the Tv stations and use that Winegard preamp to push the Tv signals through the long cable run to the house. The preamp will need to be mounted at the antenna location. Use RG-6 solid copper center conductor , tri shield or quad shield coax for the run from the preamp at the antenna to preamp power supply in the house. This type of coax will give maximum signal and power transfer. Here are places to buy Tv antennas and etc. ,
http://www.3starinc.com ,
http://www.solidsignal.com ,
http://www.starkelectronic.com ,
http://www.amazon.com. , 3starinc is a good place to buy push up antenna poles.