RE: reducing spark gap losses?

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

Comments interspersed:

>Original poster: "Laurence Davis by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>
>
>A few days ago there was a post about a clever trick (can't remember
>their name...) using smaller diameter litz wire for the secondary and 
>increasing the number of turns on the primary.  Which then reduces spark gap 
>losses.  Also having the added affect of more turns on the primary and 
>reduced voltage differential between each turn (from one of terry's 
>experiments) allowing for a tighter spaced primary.  (is that even 
>desirable?)

My recent measurements of primary AC resistance showed that the resistance
of a close-wound primary coil is less than that of a space wound coil of
the same inside diameter and total inductance.  See
http://www.laushaus-dot-com/tesla/primary_resistance.htm.  Yes, desirable, but
I make no claims as to how significant the difference is, performance-wise.

>anyway... i ramble.
>Question: compare single point static gap to multipoint gap.  i would like 
>to assume that multipoint gaps loose less energy. would i be correct?

I believe the opposite is true - single gaps are more efficient.

>a related question.  I have a vacuum gap, single point.  when vacuum is not 
>running and gap is relatively small: the gap runs well between lets say 
>30-50%, but over that, it behaves like it is 'strained,' and spark output 
>diminishes by upto half.  return the variac back down to the 30-50% mark and 
>it returns to normal operation.  would this be caused by the gap not being 
>quenched or perhaps something else?

My experience also, so I always use forced air in gaps.  The gap breakdown
voltage is reduced in the presence of hot, ionized air, and a coil with a
lower breakdown voltage gap reduces performance.

>larry d.

Regards, Gary Lau
MA, USA