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RE: Terry Gap vs. TCBOR...



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

Gary,

This is an excellent point, although I may not end up
having time, resources and money to do it right
away....time being the big one.  I have a 304tl and
90% of the components of my VTTC ready to be
assembled.  I'm working on getting prepared for my
Extra class amateur radio licence exam in a month or
two.  Plus I've been working on bringing my CW (Morse
Code) reading, copying, and sending speed up.  So with
all that and spending time with my wife and
friends....I have a lot on the burner.  This is
something I had the parts for and could more or less
slap together.  Luke asked that question which
reminded me, so I decided to outfit that Terry gap
with a Lexan base and try it out.

-Brett

Of course, I also have an air blast/sucker gap I put
together a few weeks ago that I have yet to test.



--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > 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
 >
 >