Re: TC Operation Question

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Original poster: "Emmett Secrest" <secrest2032-at-msn-dot-com> 

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Thanks for the response on the RF ground question...Ed S. you were correct 
on the turns from your calc's. I got a good solid arc of about 18" to a 
ground point from the 13.5 turn. I have my Geek Group caps now and 
hopefully will get much better performance from them. I imagine that the 
saltwater cap is not a very good performer compared to the MMC cap.  I sure 
hope so, I wasn't able to get any breakout without a nail on the side of 
the Toroid. This is my first TC so I am really hooked on these things now 
that I have seen and heard one operate. I have to admit that I was somewhat 
skeptical as to whether I would be successful. I owe a deep gratitude to 
all those on the list who have provided help and guidance either directly 
or from your fascinating postings and personal web sites. Those who are 
willing to share their knowledge and skills with others are special people.

Thank you,

Emmett
----- Original Message -----
From: <mailto:tesla-at-pupman-dot-com>Tesla list
To: <mailto:tesla-at-pupman-dot-com>tesla-at-pupman-dot-com
Sent: Thursday, December 11, 2003 7:03 PM
Subject: Re: TC Operation Question

Original poster: <mailto:Esondrmn-at-aol-dot-com>Esondrmn-at-aol-dot-com

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