Thanks for the great reply!

>secondary and large primary. I can always tell from the color of
>the secondary spark if the capacitor in the tank circuit has high
>enough Q. If the spark was thick, white, and violent, with little
>or no violet or purple-blue color; it was pulsing well. Violet,
>blue, purple, or reddish spark (or hues) tell me the cap is not

I think I see what you mean! I have noticed that the sparks will vary from
red/violet to blue/white to white, depending on what I called the level of
"output power" of the secondary. Really WHITE sparks only came when I had
a top capacitance on the coil, and then only if I drew them off myself.2
(I didn't know to retune back then :) btw-all my capacitors were glass-plate
back then. I get it though...

The Q of the capacitor determines its energy storage capabilities along with
its discharge rate, for pulse-type. The speed of the discharge, in conjunction
with the switching of the gap, produces a sort of "Q-switched" high-energy
pulse into the primary. Therefore, the same comes oout of the secondary. The
spark color is determined by the ionization capability of the secondary's
output. Lower power levels (broadband) outputs can only ionize the outer shells
of the nitrogen in the air. This is the purple/blue/red coloration. When the
AC rise-time is quicker, enough energy is produced to ionize everything in the
air, and so, the spark is white! Geez! You'd think it would be easy to infer
since the spark-gap sparks are white! Never made the connection before! <G>

>coil! If the coil had been properly capped, with no holes drilled
>and the wire never entering into the coil form, it would have
>held up without breaking down or burning up.

You are correct! The coil DID have holes drilled in it, and the wire DID go
inside the form! Can you explain to me the reasoning behind not doing that?
*Every coil* I have ever built eventually burned. I always thought it was
just poor materials, too much power or something. What is it?

A couple more questions...:)

I see a post now and then about using a variac to tune-up at lower voltages.
Could you please explain the necessity and the procedure?

On the small coil that burned, (up above), I had two different sized toroids.
(No, not at the same time. :) The smaller toroid put out sparks continuously
These were about 12 inches long. The larger toroid put out single discharges
repetitively, one following another. These were the 16 inch, double forked
discharges. Any reasons for the difference?
The long sparks were trying to get to the spark-gap and/or the capacitor
bank. Any way to avoid this?

Thanks a lot!

Dan <klineda-at-univscvm.csd.scarolina.edu>