This is the one I have. The signal strength on a 1 to 10 scale is an average of 7 on all the other channels that I do get and no signal at all on 11 and 13.
After reviewing all the posts I decided to try and relocate my antenna once again. The place I wound up placing it was only about 4 feet off the floor and inside the window sill with the antenna rotated so that it was horizontal instead of vertical like all the pictures show it when it is installed. I now get channels 11 and 13, but just barely by 2 bars and all the others have a 5 to 8 strength.
I am 32 miles from the towers and this has a range of 25 so it is a good thing that there are no tall building between me and them.