Re: Faraday cage

Hi David and all,

On Sun, 30 Jun 1996, Tesla List wrote:

> >From dwt-at-efn-dot-orgSun Jun 30 09:41:34 1996
> Date: Fri, 28 Jun 1996 22:38:33 -0500
> From: David Trimmell <dwt-at-efn-dot-org>
> To: tesla-at-pupman-dot-com
> Subject: Faraday cage
> Hello all,
> I am needing to build a Faraday cage to hopefully reduce the 
> interference my coil causes with my telephone and the AM radio reception 
> around my house.  No neighbor complaints, but just encase the FCC is 
> listening.  My question is: how fine of a wire mesh would you need to 
> block the RF from a coil running from 200 to 350 kHz?  And the 
> associated "noise"?  I was thinking of trying Aluminum foil strips, but 
> then was thinking of the grounded capacitance around my coil, as the 
> basement room I have my coil setup in is not to spacious.  So I was just 
> interested in what creative designs some of you may have come up with?
>  Thanks for any input.

Just a key thing to remember is that the square spacings should be less 
or equal to half of the wavelength of the frequency.

I usually use a 1cm x 1cm sqaure mesh - absolutely perfect.

The next thing is not to earth the cage, yet to setup a spark-gap between 
the side of the cage and ground.

	side of	|  
	cage	| /
		||     <- piece of metal rod bent like a jacob's ladder...
		     |  <--- earth.

The idea behind using a spark gap is to prevent voltage build up in the 

Anything I've missed guys?

Hope this helps,

-- "Who are the Federal Communications Commission and why do they 
    want my Tesla Coil?"

|                    Australian Nikola Tesla Society                        |
| Rodney Davies                                                             |
| Email: Rodney.Davies-at-anu.edu.au                                           |
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