My secondary consists of 28AWG enamel coated 7,500 VAC, 200� C magnet wire, wound onto a 4.25" x 23.5" thin walled PVC sewer pipe section, 68 turns/inch, for a total of 1,600 turns. After winding, I applied numerous coats of oil based polyurethane. The copper plate at the bottom is for connecting to the ground straps. The 1-1/2" x 6" toroid on top is to help prevent corona on the top windings.