Re: creepage discs

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Wightman,

Tesla list wrote:

> Original poster: "D.Wightman by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<dwightman-at-mmcable-dot-com>
>
> I figured that it was time to ask the list about the creepage dicsc on my
model
> 8-888 coil. Before the discs were in stalled I had racing arc problems, After
> tuning and tuning the problem still would pop up at high power levels. So I
> turned to the web and after surfing for awhile I came upon
> Robert Stephens coil, Which sold on EBAY, Had these devices installed on
it. I
> decided to try them. The results were impressive. No more racing arcs, Power
> levels improved. This is a rather short coil, Only 24 and 3/4 inches tall.
> Others will say the only reason for racing arcs is an out of tune condition..
> Possibly the added mass to the coil form changed the inductance, Thus
creating
> an in tune situation. To this day I wonder about that. As for the coil at 40
> amps input it gives the best performance, at 50 amps the spark gap electrodes
> start to burn up and there is no improvement in output.. Most likely the coil
> is maxed out at 40 amps.

Coils with creepage disks seem far and few between. I've only seen a couple
and one of which was
Robert's. He is probably the best to answer your question. But I do believe
whole-heartedly that
tuning is the major player in racing sparks as well as coupling. I expect
there is a point where high
powered coils will periodically produce the racing spark even when tuned
and this will vary where one
coiler may experience it and another coiler will not (shorter coils
probably more susceptable). The
creepage disks themselves may actually help to stop this occurance during
those particular high
powered experiences because the racing spark distance has substatially
increased. My coil does not
have creepage disks, but in a past life, it was rather short for it's
12.75" diameter. I added
something like 12 to 14 inches of length at some point, and I have noticed
the racing arc occurance
rarely occurs where before, it would occur quite often.

Bart A.