I am thinking of installing a Yaesu ATAS 120a in the left rear corner of my Tacoma pick up bed. There is a vertical steel channel that I currently have a mount for my Hustler antenna installed on. Due to a low garage roof at work, I will have to mount the ATAS at the bottom of the channel, this will cause the lower 16 inches or so of the antenna to be shadowed by the pick up tailgate. Will this seriously affect the operation of the antenna? I do not want to mount it outside of the bed if I can avoid it.