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: 



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.TXT     11/26/95          Graphics and text prepared by:

Richard T. Quick II                <richard.quick-at-slug-dot-org>
10028 Manchester Rd 
Suite 253
Glendale  MO  63122  USA