Re: Position of Secondary WRT Primary - Stupid Question of the day

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

At 08:22 AM 4/1/2003 -0700, you wrote:
>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?

This should work fine...



>   My aspect ratio is around 5:1... I know this is not efficient...

5:1 is actually about right...

>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.


Not a great plan there...  Try putting some chicken wire, hardware cloth, 
metal windowscreen, below your coil and using that as a ground for the 
secondary.  Even some cookie sheets would be better than what you're using. 
This is probably the biggest single problem you have.  Make the ground 
plane/counterpoise at least as big in diameter as the coil is tall, if not 
twice that.  About 3-4 feet in diameter for you.  A square would 
work.  Hook the screen to safety ground for "safety" too..


>  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.


Should work fine..