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Re: First Light in Oz and topload question



Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 8/4/01 7:21:10 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> > 
>  > * safety gap for protection (set so that it barely
>  > doesn't fire with only 
>  > the trannie connected)

Stacy,

A coil such as yours can give up to 40" sparks or so if
the cap, gap, and safety gaps are optimised.  If the total
capacitance from the bottle array is less than 10nF, this
may hurt the output, using a narrow gap setting.  If the
safety gap is set so it fires with the NST alone, this will
limit the available spark output in any case.  I set my 
safety gaps at 1/4" at each end of my 12/30 NST (1/2" total),
for my TT-42 TC which gives 42" sparks from that NST.
I used to set the safety gaps at 7/16" at each side of the
NST when I used a cap size that was closer to the 
resonant size, and I had no NST failures.  I use a sync
rotary gap at 120 bps also.  I did not get very good results
with a multi-pipe gap.... the output was kind of erratic.
I also use a 0 -140 volt output variac which raises the
voltage above the normal 120 volt line voltage.  This is
needed to force more than the normal power through
an NST which uses an LTR cap.  For a matched size
cap, the 140 V variac is not needed, but the safety
gaps must be set even wider, and NST failure is more
of a possibility.

John Freau
----

    **Vortexia, Queen of the Cajun Squirrels, met with her
disciples at the local Rotary Club to synchronize the next
phase of the revolution....**