2013 optical tests over the horizon

Before my 2013 stroke I enjoyed 481THz optical tests over the horizon. What surprised me at first was that, even when absolutely nothing was visible in the sky, clear signals could be decoded on a PC as long as the aim was correct. My tripod and aiming left a lot to be desired!  If I was fit enough to repeat these tests I think a much better tripod would be called for allowing better repeatability.