Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com> > Has anyone here ever compared large spheres with toroids for top > loading of high-power TC's? > > Ed Toroids do much better than spheres. I believe the first person to start using toroids was back in the 1970's from what i've read from Richard Hull's historical notes. Dan