Hello all, I have placed a quick and dirty schematic of my Grid, audio modulated, Tube coil on my website: http://www.pond-dot-net/~davidt/webdoc2.htg/Tube%20coil/audio_mod.jpg A coil such as this should make a great attention getter. So far, John Freau has had some success replicating results using a 813 pentode tube. Any comments, suggestions are encouraged, Regards, David Trimmell