Position of Secondary WRT Primary - Stupid Question of the day

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Original poster: "Bruce Boettjer by way of Terry Fritz <teslalist-at-qwest-dot-net>" <bruceb75-at-cox-dot-net>


Hello,

In just a couple of months of subscription to this list, I have amassed a
wealth of knowledge... Someone should publish this stuff!

I have just completed a small system, but am having no luck getting any
spark, or even glow.


There are some specific 'failure points' I think are present, but am unsure
about, due to my lack of experience.  I would appreciate any response...

1.  The secondary sits on the primary's plywood base in such a way the the
windings appear to not match up.  Stated differently, the primary is a
uniform 0.75" from the surface of the plywood.  The secondary winding does
not start until 1" from the plywood.  Is this a problem?  Do I need to pop a
hole in the plywood to 'lower' the secondary into?... If so, then how far is
adequate?  My aspect ratio is around 5:1... I know this is not efficient...
can this be 'made up for' by lowering the secondary with respect to the
primary?

2.  For initial testing, I have been wanting to work indoors (my 10' copper
pipe that is driven into the ground is in the backyard...).  This has
prompted me to live a little dangerously by connecting the bottom conductor
of the secondary winding to the green 'ground' that runs through my house
and goes to each and every AC outlet.  While I understand the potential
personal risks beforehand, and have taken adequate prophylactic (that's such
a great word!) measures, there is still no joy... Is there a problem with
this method, other than the obvious RF burn hazard?

I was hoping that those much more knowledgable than I could take a look at
this system and tell me where I went non-linear...

The system is comprised of:
1.  15KV x 30mA NST.

2.  Homebrew Richard Quick style stationalry spark gap
	a.  10 pieces of 5/8" copper pipe, 4" long.
	b.  .010" to .020" spacing(.010" feeler will pass through, .020" will not).
       c.  Sealed wooden box with a wafer fan (110V AC) sucking air.
       d.  Spark Gap is in parallel with transformer.

       i.  With no Cap, there is much noise and light from this gap.
       ii. With Cap, there is much more impressive noise and light from this
gap.
       iii. I can see static on my neighbors TV when I run this thing (Any
easy suggestions for                          isolation?).

3.  MMC Cap comprised of 15 'Geek Group' 0.15uF -at- 2KV caps in series (1
string)
	a.  Being a graduate of the "Ouch! Electricity really hurts 'school'", I
strongly believe in safety as a design practice, not as an afterthought -
therefore, each cap has a 10M Ohm, 1/4W resistor in parallel with each cap
(so much for the soap-box).
       b.  A 30KV cap that has more capicitance (overrated) is much better
and potentially longer lasting than a cap that has just enough capicity for
the task at hand (IMHO, please correct me if I'm wrong).
       c.  The Cap, and primary are in series.  This assembly is in parallel
with the gap.

4.  Primary Coil
	a.  ID of 6"
	b.  13 turns of 1/4" copper tubing, spaced 1/4" apart (holes in keepers are
0.50" apart).
       c.  Flat, pancake style.
       d.  I 'machined' keepers out of a plastic cutting board.  There are
five keepers, bolted down with 6/32 nylon screws in a circle, to a 3'
diameter piece of plywood.
       e.  There is no ground 'strike-rail', yet.
       f.  The center of the coil is connected to the gap.
       g.  The 'tap' is connected to the cap.

	i.  The math says that the tap should be around 9 turns (and some change).

5.  Secondary Coil
	a.  e-bay special
       b.  3.550" PVC, 20" long
	c.  18" of 20 gage wire, with a nice coating
       d.  winding starts 1" from each end.

6.  'Washing Machine' Toroid, 24" OD, covered in Aluminum tape.

Continuity checks performed with a multimeter show a good circuit through
secondary and toroid, as well as good primary circuit connections (Crimp
terminals and alligator clips, all with soldered conenctions).

For those who have made it this far into this increasingly verbose post(I
really didn't plan it this way), Thanks!  I really would appreciate any
feedback or stories that may help.

Regards,

Bruce Boettjer
Oceanside, California