Dave, I believe that some of the info John referred to is found
here . You'll note that the highest bandwidth needed is about 37 MHz for 720p. Bandwidth is generally defined as the point where response has dropped by 3dB, and it's considered that there would be no visible deterioration at that point. In addition to a loss in the receiver, there's some in the cables, but for usual home distances it amounts to no more than one or two tenths of a dB and can be disregarded. The author suggests a margin of twice the bandwidth needed, and such a suggestion is fairly common, although it's rather conservative. My view is not to be concerned with any bandwidth of 30MHz or more and that 60 or 100MHz is unlikely to be of visible advantage to any human being.
