Capping secondary coil forms

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

Original poster: "Gregory Peters by way of Terry Fritz <twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>

Hello all,

All these years I have been capping my secondary forms with
plexiglas/acyrlic or lexan/polycarbonate discs. This apparently
prevents arcs down the centre of the secondary. I have never
questioned this theory until now. I just made a new secondary and
really couldn't be bothered capping it, though I eventually did
anyway. But I really think that if the toroid is large enough, arcing
inside the form wouldn't happen anyway. I've noticed that arcs never
seem to leave the centre of the toroid, supporting my theory. Is this
just another theory that stems from the days of doorknob discharge
terminals? Anyone out there running uncapped coils with outputs that
vastly exceed the winding length?

Cheers,

Greg.