Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <ashumate3-at-aol-dot-com> Copper clad and copper pipe Having been involved with a lot of grounding projects copper clad is the best. While copper pipe is fine it will not large currents in a short circuit or lighting strike. If you are concrened about RF it will travel the outer coating. Al Shumate