Re: triggered gap performance?

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

Original poster: "Dr. Resonance by way of Terry Fritz <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


We use two tungsten 3/8-16 NC threaded 1/2 inch dia. electrodes that thread
in standard 1/2 inch dia. x 2 1/2 inch long brass rod.  This fits into a 1/2
bore in 1 x 1 inch square brass stock x 2 1/2 inches high mounted on
phenolic rod.

With this large surface area no additional quenching is required.  On the 60
mA xmfrs we use two of these sparkgaps.  Sometimes a small 75-100 CFM fan
helps quenching but most of the time, at this power level, running with a
.01 or .02 MFD cap, the fan actually overquenches and reduces the output on
the sec. coil.  Also, at this power level (Joules) you should be using min.
of 1/4 inch dia. tungsten.  We prefer the 1/2 inch dia. size for best
quenching without excessive losses.  Our 1/2 dia. electrodes are bonded
directly to copper and then threaded into brass rod stock.

The gaps are spaced a total (sum of all gaps) at 0.200 to 0.220 inches.  We
seldom run over 0.240 inch total with NST systems.  We use up to 0.280 inch
(total) with PT's and usually a small 9 inch dia. 6 electrode 1/4 inch
tungsten RSG running at 1800 RPM (around 180 bks/sec).

In spite of what's be reported, we do use NST's with RSG's.  I keep the gap
spacing tight 0.180 inch max.  I think many experimenters ran with too wide
a gap and perhaps too many breaks/sec. on their RSG's.  This will destroy a
NST.  With proper monitoring of gap setting and keeping breaks to a
reasonable level (under 200 bks/sec) RSG do work well with NST's.    They
are not required until current exceeds 100 mA value, ie, 15 kV, 120 mA
units.  Of course, you do have to use a high quality filter like Terry F's
or equivalent.

Dr. Resonance


 >          do you mean two spark gaps for triggered operation or that a
 > triggered gap at this power level wont outperform two brass static air
 > breakdown gaps?
 > cheers
 > colin