Re: Grounding questions

From: 	Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: 	bert.hickman-at-aquila-dot-com
Sent: 	Saturday, July 26, 1997 9:12 AM
To: 	Tesla List
Subject: 	Re: Grounding questions

Tesla List wrote:
> From:   Brandon Doughan[SMTP:fiveht-at-well-dot-com]
> Sent:   Friday, July 25, 1997 6:02 AM
> To:     tesla-at-pupman-dot-com
> Subject:        Grounding questions
> Hey you HV freaks-
>         Well, The High Voltage Camp is shaping up for burningman next
> month.  (What is Burningman??  www.burningman-dot-com)  So far, Ive wrapped
> an 11" X 40" coilform with 10 gauge (yes, that's 10 gauge...) enamaled
> Cu, have a few torrids made and am finishing up the base.  Being in a
> small apartment in San Francisco, I've no opportunity to test run it.
> This leads me to a few questions for you all:
>         If you don't know, the Buringman event takes place on a playa, an
> ancient dried lake bed that stretches for miles and is almost perfectly
> flat.  I'm worried about grounding out there.  My plan is to take the
> bottom lead of my secondary to a piece of rebar that I've dug down and
> pounded in as far as I can.  I also plan to soak the area with salt water.
> Think that will be good enough?  I also plan to have a second grounding
> rod for the center tap of the NST and casing of the gas-powered generator
> Im planning on luggin out there.  Thoughts?  **I'm also worried theres a
> chance the metal stakes that the thousands of other people will also be
> pounding into the ground for their tents and camps could somehow draw
> some current**  Thinks there's any chance of that?  I remember Tesla
> mentioning being able to draw sparks off of water pipes miles away.  I
> certainly do not want to injury someone 100 yards away.
>         Second question:  Im not familiar with portable generators.  How
> big of one do I want?  I'm using a 12KV NST having 60ma through a 1/4" Cu
> tubing flat spiral primary.
> Thanks for any help!  Brandon


While the ground you've proposed should be adequate, another piece of
REBAR wouldn't hurt if you need to increase power (see below). As long
as the other campers are at a distance significantly more than the
striking range any streamers, they shouldn't be impacted from any ground
currents. To pick up appreciable power from ground currents, you'd need
to have another resonator that was tuned for the same frequency you're
running your coil. Near-field RF effects may cause them to get little
shocks off any nearby ungrounded conductive objects - coolers, bicycles,

The only problem I see is that the larger size of your secondary may
require you to use an additional 12-60 in order to supply enough energy
to energize the coil properly. You didn't say what size tank cap you
plan on using. I found that with .02 uF on my 10" coil, it took at least
90 mils to run it properly and 120 MA to really make it sing. You really
should try out your coil ahead of time to make sure that you won't be
disappointed out in the desert, and to make any necessary design or
construction "tweaks" while you're still in civilization. A 3000 Watt
portable generator should be more than sufficient to run your coil, even
if you go to two transformers.

Good luck at Burning Man!

Safe coilin' to you!

-- Bert H --