RE: More Urban coiling concerns

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

Original poster: "Vanderputten, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <gvp-at-pvaintl-dot-com>

Assume I wish to use a 350w 3.5" x15" table top coil in a theatre space in a
basement where the closet person will be about 10 feet. It operates on
dedicated ac line from the street, but there is an electronic dimmer device
on the mains (everything else is non-electronic) The device will arc
directly from the toroid to the rf ground, a 6-8" distance. The NSF is
protected by MOVs,  500 pf caps, and a safety gap to ground as well as  500
ohm/100w resistors and small chokes in front of the tank circuit, much like
Terry's . The primary cap has a safety gap as well. The SG is the tube-type
stationary SG. 

My issue here is that I wan to protect the audience (hearing aids, who
knows, maybe a pacemaker)  and any electronic equipment that may be nearby
from RF interference. I will create an rf ground 20 feet away via a 4 inch
metal storm drain. I would ground everything from the NST to the secondary
to that as well as a metal plate under the coil and chick wire back drop.  

I will  install MOVs across the NSF primary hot and neutral to ground as
well. 

Now, I get confused on the correct use of EMIs between the variac and the
NSF. I have read everything from normal install, back wards install, two in
series with one front and one back. I have also read that the EMI should
ground to rf (which I don't like) or to the mains ground, or to another
ground that is not the mains or the rf (intriguing, and very possible where
I am located). 

So, how much rf does a modest unit like this generate? Over what distances?
How can one tell (is an am radio sufficient), and how much difference does
it make that it will arc directly to ground and not be permitted to freely
produce streamer? How much rf is generated by the SG? How effective is an
rf-grounded metal shield over it? 

Any advice welcomed.

Gary

 -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
Sent:	Monday, June 11, 2001 2:12 PM
To:	tesla-at-pupman-dot-com
Subject:	Re: Garage door opener protection

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Steve,

Depending on exactly how your opener is designed, one can often fairly
easily
remove the electronic PC board from them.  The connections to the board are
usually connectors or connectors could be added.  Then you could just remove
the sensitive electronics board when you run your coil.

One should also look around for telephone, cable TV, and lawn sprinkler
stuff
in the garage also.  Good idea to remove pressurized cans and flammable
stuff
like the lawn mower gas can too...

Cheers,

        Terry


At 09:16 PM 6/10/2001 -0700, you wrote: 
>
> I am in the process of buiding a pole transformer powered coil
theoretically
> capable of 8 foot arcs. I would like to run this coil at perhaps partial
> power in my garage at times. Like many people, I have a garage door
opener.
> Is there any advice on how to protect the opener from damage? The only
idea
> that I have is to build a grounded Faraday cage around it and unplug its
> power cord. The Faraday cage will take care of the electric field but what
> about the magnetic field?