RE: Terry Gap vs. TCBOR...

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

Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com> 

Measuring and comparing arc length is a highly subjective thing, where
the results are likely to never be repeatable.

May I make a suggestion?  If the difference in performance is not
dramatic, replace your primary coil with an appropriate number of
series-connected 500W halogen floodlight bulbs (total wattage being
"somewhat" higher than your NST's VA rating), and place them in a
somewhat light-tight environment.  Monitor their brightness with a
photoresistor and ohm meter.  The lamp brightness and photoresistor
resistance will correspond with repeatability to the power delivered to
the primary coil.

Obviously this test will not show differences in quenching, but it will
show relative gap losses.  If streamers connect to a grounded target,
you're probably achieving first-notch quench anyway.

Gary Lau
MA, USA

Original poster: "Luke" <Bluu-at-cox-dot-net>

Brett:
Glad you are doing this.  Can't wait to see the write up you do.
How are you measuring the arcs or output for the comparison?

After I get my coil up and running I just might want to learn some of
this testing stuff and tinker a bit.

Tahnx

Luke Galyan
Bluu-at-cox-dot-net
http://members.cox-dot-net/bluu

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, February 28, 2004 9:14 AM
To: tesla-at-pupman-dot-com
Subject: Terry Gap vs. TCBOR...

Original poster: Brett Miller <brmtesla2-at-yahoo-dot-com>

Luke (and Terry might be interested too),

I have started the restoration of the Fritz linear
static gap.  I mixed up some T-88 aircraft grade epoxy
(good stuff I might add) and set up the cu pipes on a
nice 1/2" thick Lexan base I pilferred from my
plastics crate.  Tomorrow it should be pretty well
cured and I can start firing up and performing tests.


I'll soon be providing pictures of both the gaps as
well as scope waveforms of quenching for the
respective units.

Just remember, the diameter of the pipes is much
greater in the TCBOR gap, so heat sinking/cooling will
be naturally better in the TCBOR.  This is definately
something to consider when analysing the results.
This test will definately not be controlled, nor will
it be double blind.  Nevertheless, I think some
tentative conclusions may not be life threatening.

I must also not forget to take measurements of each
gap and provide total gap spacing for each gap unit
tested.  I used two index cards stacked to space the
pipes in the Fritz gap.  Those will be easy to measure
with a caliper.  I can use a feeler gauge for the
TCBOR.....something I should have done a long time
ago.

I hope a few people will take an interest in this
little project.  I know Luke is interested (plus me),
so that makes it worth doing right there.  What we're
really wanting to know here is whether or not
distributing a spark over many gaps for greater
quenching is desirable over using few gaps to minimize
loss?  Where is the balance?  Is this a sensitive
parameter that must be matched to specific systems?
If we're lucky we might learn more about whether or
not 1st notch quenching is the "holy grail" of spark
gap design (see Richee Burnett's page).

-Brett

_