Re: Resonant freq only major shielding concern?

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

Original poster: "S & J Young" <youngs-at-konnections-dot-net> 

Hi Rick,

It's hard to specifically answer your question.  It depends on how sensitive
your electronics are to know how extensively you need to shield.  As
examples, if you are using digital instruments, then you need very complete
shielding to ensure reliable readings.  I use a Wavetek 27XT to read RSG
break rate (frequency), and I have to use a 10 foot fiber optic "cable"
going into a shielded box made of quarter inch hardware cloth which
completely encloses the 27XT and fiber photodetector circuitry.  If you are
using analog meters, you don't need any shielding.  If you are preventing
feedback into a TSG pulse generator, you should use completely boxed in
circuitry and filter power going in, etc.  Distance is your friend - keep
sensitive electronics as far away from your coil as practical.

You absolutely don't need mu metal shielding for your stuff which probably
is fairly insensitive to magnetic fields.  Your aluminum shielding and
shielded wires should be adequate.  If your openings into your shield boxes
are small (e.g. 1/4 inch or so) you will have adequate shielding well into
the hundreds of MHz.
--Steve Y.


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, November 26, 2003 7:35 AM
Subject: Resonant freq only major shielding concern?


 > Original poster: potluck-at-xmission-dot-com
 >
 >
 >
 > Hi all,
 >
 >
 > Besides the resonant frequency of the coil what other RF components are to
 > be considered when shielding electronics for operation in a telsa
 > environment?
 >
 > At present all electronics (3 units) are enclosed in .100" thick aluminum
 > enclosures with only one "port" leaving a lot of flat sides :) The 3 units
 > are interconnected with shielded #20 twisted pairs. There are 4 shielded
 > pairs in the cable with another shield layer overall.
 > (Avoiding ground loops was a major concern during design and construction)
 >
 > I see there's Mu-Metal foil .010" thick 15" wide at McMaster-Carr but at
 > $32 per foot ..... ouch
 >
 > So what is it I'm shielding against?
 >
 > Any insight would be appreciated. :)
 > thanks
 >
 > Rick W.
 > Salt Lake City
 >
 >
 >