Here is the funny thing...... I put it in a garbage bag, to help weatherize it and put it up on the roof...horizontally. I tied a rope around on of the vents and put it through the caring handle (it literally is the size of a box fan....along with a handle) and there it was....30ft off the ground. No one would know. It would still be up there had I not taken it down to put some inline ferrites on it. It began to snow and I didn't want to go back on the roof and have me come sliding down. It's slung against the fence waiting for the thaw.
I would expect you would really have to look hard for it.
As loops go (MFJ-1780), it's not as high Q is its brothers but it gets the job done. It does work better 20-30 feet off the ground, but it's sitting 6ft up slung against my wodden fence and it can compete with my 40m folded dipole 25ft up.
Here is the unit with a side taken off. It's depth is only about 4 inches and no one could tell what it was bundled in a dark garbage bag. Keeping the water out seems to be all it needs. We all know the winter we have and mine has not quit yet.