Here's the improved junk box coil in finished form. The red secondary and the little wooden junk sale table are about all that remain of the original junk box coil that I built in the UK. On top is a bigger 3.5" x 14" toroid made from two styrofoam floral wreath forms glued together back-to-back and covered with Aluminum tape. Beneath the new flat spiral copper tube primary you can see the big single static vacuum gap made from copper pipe. Also gone are the salt water caps and the dinky 450VA NST. In their place are a new, low-lossMMC and a more potent 1080VA NST supply. This coil puts on a pretty impressive show, with multiple branched streamers up to 36". It also howls like a panther passing a kidney stone! Hearing protection is a must!