Glass Caps

From:  Gregory R. Hunter [SMTP:ghunter-at-mail.enterprise-dot-net]
Sent:  Sunday, January 25, 1998 9:19 AM
To:  Tesla List
Subject:  Glass Caps

Dear Readers,

Anyone ever run a medium or large coil with a glass cap?  I'm trying 
to figure out how bad the heating problem is at 1KVA and up.  I've 
only built 3 small coils, all under 500VA.  All I've ever used is 
glass caps, and I've only experienced one unexplained failure in a 
foil & window glass cap on a 380VA coil.  A hasty autopsy revealed 
glass panes laced with very fine, spider web-like cracks.  Might've 
been due to thermal effects.  My current 450VA coil runs with salt 
water bottle caps.  I think the water sinks so much heat, I'll never 
be able to detect RF heating at such low power input levels.