I was fooling around with a 7dbi antenna. Attached a coax for use outside. I don't exactly how these wireless units operate, but was thinking about ground planes. I used a simple rf pickup device watching 10 hz pulses from unit. As I moved from top of antenna I went through nodes, but continued to get nodes on coax down a ways. I set the rf monitor out from antenna, and installed ferrite core around coax about 1/4 wavelength from connector. I think it improved overall radiation, and the rf did not go beyond the core. What you think?