Text file for COILBLD2.GIF, graphical instructions for construction of high performance 1/4 wave Tesla resonators. 4) Once the coil is wound, it is sealed to prevent corona leakage and to help protect against electrical breakdown between turns. Sealing also prevents the windings from loosening up on the coil form. I use the same sealers mentioned earlier, those being petroleum based polyurethane, two-part clear epoxy paint, or water free acrylic. Coats of sealer are applied with a brush or spray until there are no ridges and valleys in the wire. In other words the coats must build up until the wire is completely imbedded in sealer. A fan and radiant heat source may be used as required to speed the cure rate of the sealer. Rotating the coil on the winding spindle will aid in obtaining a smooth coating that is free of runs and drips. 5) Two plastic disks are cut to match the ends of the coil form. The plastic should be approximately the same thickness as the coil form walls. Experience shows that plexiglas is both readily available and works quite well in this application. Dry fit and file the caps as necessary until a good match is made to the coil form ends. I rough up, or score, the matching surface of the plastic disks where they will be bonded to the ends of the coil form. This provides a surface around the edges to give the epoxy adhesive a bite. 6) Make sure all surfaces are dry, clean, and free of oil. Place a bead of fresh, good quality, clear two-part epoxy adhesive around the top of the coil form and the matching end cap, then cap the end of the coil with the plastic disk. Weight the end cap down until the epoxy has cured; then flip the coil over and repeat the procedure to cap the other end. I will stop here to make an important note: NO HOLES ARE EVER DRILLED INTO THE SIDEWALL OF THE COIL FORM! WIRE IS NEVER ALLOWED TO ENTER INSIDE OF THE COIL! Ideally the secondary coil should be hermetically sealed. This prevents internal electrical breakdowns of the coil and prevents the uptake of moisture into the coil form when PVC plastic pipe is used. If holes are drilled into the coil sidewalls, and/or, the wire is allowed to enter inside of the coil, then spark lengths that exceed the length of the winding will almost surely cause the coil to fail. Once a coil has failed in this manner it is not repairable. One small hole may be drilled into the bottom end plate to allow the air pressure to equalize, but under no circumstances should any other holes be drilled. COILBLD2.GIF 6/8/95 Graphics and text prepared by: Richard T. Quick II 10028 Manchester Rd Suite 253 Glendale MO 63122 USA