Original poster: "Gary Peterson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <glpeterson-at-tfcbooks-dot-com> There's a tunable high-impedance LF preamp circuit posted at http://frodo.bruderhof-dot-com/ka2qpg/ad712pre.htm. A short introduction to Tesla's air-ground system for wireless telecommunications is posted at http://www.tfcbooks-dot-com/writings/w_system.htm.