The larger/bigger a directional antenna is the More directional the antenna is in the forward direction and more signal is received at the forward/front of the antenna , and the more signal is Not received at the , sides , angles and back of a Big antenna.
A smaller antenna will receive less at the forward/front of the antenna and receive more Tv signal at the , sides , angles and back of the antenna.
Your location and signal strengths of the Tv transmissions and the locations of the Tv transmitters.
Calls for a antenna that is smaller , that is why I recommended a Winegard Hd7696P antenna.
A balance of forward/front antenna gain and also the ability of the antenna to receive more signal at the , sides , angles and back of the antenna.
All of this and more , a lot more , takes , many , many , many , many , words to explain.
All of the information is on the internet to look up.
I take it all in to consideration and recommend a antenna or antennas that will most likely get the job done.
If the HD7696P antenna and AP8700 preamp aimed at the west/south/west Tv stations does not do a good enough job of receiving the Tv stations to the north/north/west.
Then the antenna can be mounted on a Channel Master CM9521A antenna rotator. http://www.channelmasterstore.com
Rotating the HD7698P antenna so the antenna 'looks at' the tv stations transmitting antennas will receive the the Tv stations/channels much better.
The down side of a Tv antenna rotator is.
Must wait for the Tv antenna to turn toward the Tv stations transmitting antennas.
Waiting for the antenna to rotate Is Not channel surfing friendly.
And not every one in the house will agree on where the antenna is pointed.