% ft is asking for RF in power lines, cable coax, and telephones.
Can not attach it to the house??? No problem.
Mount the A99 on an extension ladder and lean the extension ladder against the house.
When you are done using the antenna take it down and put it away.
No worries about lightning strikes etc.etc.
You have a tree?? Hide it in the tree, suspend it so it does not touch any branches and call it done.
Friend of mine in Atlanta has his I2K suspended in the air hanging from a tree branch.
Long story short, where there is a will there is a way.