Gap setting?

From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent:  Friday, June 12, 1998 12:46 PM
To:  Tesla List
Subject:  Re: Gap setting?

to: Gary

You can run a larger gap up to 0.200 inches but anything larger (total gap)
will spell certain doom to your NST.  They are not made to provide their
full rated output potential for a long period of time -- only long enough
to ionize the gas in the neon tube and then they drop back to around
600-800 volts and just serve as a current source.  

When I mentioned the .045 inch setting I was referring to the initial
"tuning" conditions for the coil not its normal in tune operating mode. 
Normal is .150 to .200 inch setting with only 3 total gaps necessary for a
30 ma drive current.  5 gaps work best with a 60 ma dirve and 7 gaps work
great with 120 ma drive.  Anything more is "ok" but not necessary for good
performance.  A small 150 - 200 CFM blower fan adds performance with a 60
or 120 ma xmfr.  The vacuum cleaner suction type gaps also work great with
small to medium size systems.


> From:  Gary Lau  11-Jun-1998 0917 [SMTP:lau-at-hdecad.ENET.dec-dot-com]
> Sent:  Thursday, June 11, 1998 8:34 AM
> To:  tesla-at-pupman-dot-com
> Subject:  Gap setting?
> >From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
> >
> <snip>
> >With a 30 ma NST you only need 2 or 3 gaps.  Set at .015 inches on each
> >for .045 inch total.  Try this first and see if it runs with this
> <snip>
> I don't see how the gap setting is derived from the power supply current
> rating.  I would think that it is voltage-dependant, not
> current-dependant.  Rather, I would think the current rating would
> dictate the required "beefyness" of the gaps, how much heat it must
> dissipate, while the voltage rating would dictate the gap spacing.  I
> know that for my 15KV/30mA coil, that going from 5 to 10 gaps of .03"
> each, made a world of difference in performance.  The suggested gap of
> .045 sounds way too short, IMO.
> Gary Lau
> Waltham, MA USA