Re: TC Operation Question

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

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 12/10/03 11:08:34 AM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>I am new to TC's so I have a lot to learn. I would like to know what
>relationship the RF ground has to the operation of the TC. I know it is to
>direct RF to ground but what I was wondering was what effect it has on the
>operation of the coil if it is not present at all. I am still waiting on my
>MMC's from The Geek Group and in the mean time I built a saltwater bucket
>cap. I hooked it up and tried out my coil without an RF ground (it was
>raining and I was impatient). It would make the florescent lights glow but
>would not generate any arcs.  I don't know if it is a coupling issue, a
>tuning issue or the lack of an RF ground. I probably haven't provided
>enough info but any insight you experienced coilers could provide is
>appreciated.
>
>12KV 60mA Xfmr
>.25" cu tubing primary 15 turns w/ .25" spacing
>
>secondary 4.5" dia. 22.5" tall 1086 turns
>primary inner turn to secondary spacing 2.5"
>plane of primary 2" above start winding of secondary
>RQ spark gap with 5 pieces of 1" x 2" cu total gap .25"
>
>Tank cap= 12 Corona bottles in saltwater,  capacitance = ?
>
>Toroid 4" above top secondary winding
>Major Dia. 22"
>4" aluminum dryer duct
>
>Thanks in advance for everyones guidance.
>
>Emmett


Emmett,

Several folks have responded regarding RF grounds.  I reccomend that you 
use one, if not a ground rod, then some metal screen laying on the floor at 
least.

I ran some numbers on your coil.  Assuming the bottle caps are about 700 pf 
each, and in parallel, that makes the primary cap about 8.4 nf.  You should 
be able to tune the coil when the primary is tapped out about turn 13.5 on 
the primary.  Lay a wire on the toroid, just protruding off the edge and 
place another wire about 6" away that is connected to the RF ground.  Try 
different tap positions around turn 13 and 14 and tune for maximum spark.

Have fun,

Ed Sonderman