Faraday cage question.

Discussion in 'General Electronics Chat' started by strantor, Apr 5, 2012.

  1. strantor

    Thread Starter AAC Fanatic!

    Oct 3, 2010
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    I was under the impression that all you had to do was build a wood frame and stretch some wire mesh over it and you had a "blocks anything" faraday cage.

    Then I read this post and learned that's not true.

    I was watching a show the other day and a guy was building just a wire mesh faraday cage. He said it would protect his electronic equipment in the event of a massive solar flare or EMP from a nuclear weapon.

    Was he wasting his time? would that work?
     
  2. Wendy

    Moderator

    Mar 24, 2008
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    It could work. Problem is quality has to be uniform and high. Even a minor flaw and your effort was wasted.

    The comment that you need not ground a Faraday cage is true, but the other side is grounding enhances the effect.

    I've worked around a lot of RF rooms in my time, they can be a pain to maintain.
     
  3. Adjuster

    Well-Known Member

    Dec 26, 2010
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    It also rather depends on what you are trying to protect and from what. A solar flare of a level posing a minor risk is one thing, a deliberately engineered military EMP may be much worse, though just how much is presumably classified information.

    I don't have a clue about the energies involved, but might a large thin wire mesh cage simply melt due to the currents involved? Would this happen outside the radius survivable by humans, with the possible exception of users of pacemakers or other electrical or conductive prostheses? Grim ideas.
     
  4. #12

    Expert

    Nov 30, 2010
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    I have also worked in screen rooms, but they were trying to not let any radiation out from the secret transmitters I was working on. I was amazed! Hundreds of watts at hundreds of megahurts, with the carrier cranked all the way to square waves, into a "cantenna" and it was still a secret, 20 feet away.

    Now we have somebody tying to stop a walkie talkie and it doesn't work? Got me stumped!
     
  5. Adjuster

    Well-Known Member

    Dec 26, 2010
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    On the other thread, the OP is only trying to stop the walkie-talkie by the attenuation of a screening cage. No jamming or disruptive extra transmitter is involved, but since the transmitter and receiver are only metres apart, much closer than their ultimate range, a very large attenuation will be needed.
     
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