Re: Fritz vs TCBOR -- initial results in...

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 2 Mar 2004, at 21:02, Tesla list wrote:

 > Original poster: Brett Miller <brmtesla2-at-yahoo-dot-com>
 >
 > Malcolm,
 >
 > --- Tesla list <tesla-at-pupman-dot-com> wrote:
 >  > Original poster: "Malcolm Watts"
 >  > <m.j.watts-at-massey.ac.nz>
 >  >
 >  > Hi Brett,
 >  >             Why is it that the TCBOR waveforms show
 >  > a clear first
 >  > ringup and the "Fritz gap" waveforms do not?
 >
 > I would like to know the answer to that as much as
 > you would.
 >
 >  > I almost think I am
 >  > looking at the primary waveform in the case of the
 >  > latter.
 >
 > No, the trace here is definately derived from the
 > secondary efield caputured here via a 12" antenna
 > attached to a BNC => gator clip lead, placed 8 feet
 > from the running coil.

In that case, it is most likely that an e.s. transient from the
primary when the gap fires is triggering the scope (unless you are
using a delayed trigger). It would appear that the many-pipe gap is
not sending out such a good signal. Y-N?

 >  > No mention
 >  > is made of the spark condition for either test
 >  > although it is easy to
 >  > infer that the TCBOR waveforms were captured with
 >  > air-streamers.
 >
 > Actually I did mention it if you read the name of this
 > .jpg, which documents photographically the coil
 > behavior for the quench waveforms gathered using the
 > Tek 922R.
 >
 > http://hot-streamer-dot-com/brett/misc/amount_of_breakout_for_test.jpg

I am unable to revisit the website as you know - I will as soon as
hot-streamer is back up. I take it though that both output spark
conditions were identical? I remember seeing one picture where wispy
spark-ends were just reaching for the ground rod.

 > The coil was kept at a point just beyond where
 > breakout first begins to occur.  Around 60V on my 140V
 > 20A variac.  That why I included this photo and named
 > it appropriately:
 >
 > I tried to intimate that spark conditions were those
 > found at minimal breakout by the way I named the above
 > photo.  I may or may not write a more organized paper
 > out of this "study" as I said earlier.
 >
 >  > The
 >  > fact that the latter gap got hotter in operation
 >  > suggests that my
 >  > hypothesis about quench efficiency corresponding to
 >  > gap loss is not
 >  > entirely invalid.
 >
 > Possibly.  But it could be that the loss the TCBOR is
 > experiencing is due to a mechanism that isn't quite as
 > obvious as electrode heating.

It's difficult to imagine that radiation could account for it.

 > I know from experience of using that same TCBOR in
 > this system that it performs wonderfully when opened
 > up to a much wider spacing using between 4 and 6 gaps.
 >   At 3 gaps and at the .158" test spacing it performed
 > poorly streamer length (and apparently quenching)
 > wise.

That suggests that the difficulty of (re)firing multiple gaps might
be the key to this. I wonder how the actual firing voltages
compared?? The 60% setting on the variac is not truly indicative
since some resonant charging is going on.

 >  > However, the waveforms really make
 >  > the test look a
 >  > bit like they are in the apples vs oranges category.
 >
 > Maybe they are.  That was part of Luke's question and
 > the main reason I did the test.  Lot of small gaps, or
 > fewer large gaps?
 >
 > Idetical conditions except for 1.)electrode diameter
 > and 2.) number of gaps
 >
 > Review the .txt file for exact spacing.
 >
 >  > Can you comment
 >  > on any of these points please?
 >
 > Hope I made that clear.  I guess I should have got a
 > real paper together before I released all this stuff.
 > This started out with something I was discussing with
 > Luke off list, and seems to be getting bigger.  Pretty
 > fun stuff though.  I wouldn't even be messing with
 > this if it wasn't for Terry and Richie Burnett...and
 > others.  I'd like to thank those guys for being an
 > inspiration to try to do things like this.

I have tried multiple gaps in the past and not found the construction
effort to be worth it. Howver, comparing copper pipes with a much
higher temperature material like tungsten carbide is also in apples
and oranges territory. I haven't gone to quite the extreme of 20-odd
gaps I must admit. I will revisit that in the future.

Thanks for doing the tests.

Malcolm