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faraday cage

Discussion in 'Prepper Forum' started by jon666, Feb 16, 2017.

  1. jon666

    jon666 Well-Known Member

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    i wanting to build a faraday cage. what do i need to build one. i want to put my kenwood inside.
    any help would be appreciated.
    thanks.


     

  2. Robb

    Robb Yup

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    Q: Why?
    Curious.
     
  3. jon666

    jon666 Well-Known Member

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    emp just in case of emergency
    you never know.
     
  4. Robb

    Robb Yup

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    Your avatar picture dude is using a faraday cage in the form of a tin foil hat. You car is a natural faraday cage. Unless you run a car battery indoors; then any emp pulse will still get through the house wiring. Any antenna is an emp magnet. If you are talking about doing this for your house/radio room; you will have real problems ahead of you doing that.
     
    #4 Robb, Feb 16, 2017
    Last edited: Feb 16, 2017
    Captain Kilowatt likes this.
  5. Sarasota Slim

    Sarasota Slim Well-Known Member

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    I was considering turning my garage into a Faraday cage, just for fun. It's a big, 2 bay, detached garage. Plenty of room.

    I need to read up on the topic, though. I don't know enough about Faraday cage theory, yet.
     
  6. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Forget most of what you see and hear on prepper forums. An effective Faraday cage is NOT as simple as placing your gear in a metal garbage can or wrapping in a layer of aluminum foil. :rolleyes: You need several layers insulated from each other and there must be no wires protruding from the shield layers.
     
    357magnum likes this.
  7. Sarasota Slim

    Sarasota Slim Well-Known Member

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    What? You can't trust everything you read on the interwebs?

    Just out of curiosity, how many layers is "several"? What should one use to insulate between layers?

    My interest in the topic is more theoretical, for now. I just like knowing things.
     
  8. Robb

    Robb Yup

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    Not all emp is the same strength. Depends if it was a result of a air burst nuclear device, or a small scale dedicated emp device, or lightning. Saturation of free electrons varies in all three examples.
     
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  9. Sarasota Slim

    Sarasota Slim Well-Known Member

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    For the sake of discussion, let's assume that the cage is for a worst case scenario. (Also, let's assume that we've survived the worst case scenario; otherwise the contents of the hypothetical cage won't matter much, lol)
     
  10. 338_MtRushmore

    338_MtRushmore Well-Known Member

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    I think this idea needs to be carried through to a complete thought. What are you trying to achieve? If it is just to be the cool guy with a radio that gets propaganda from random countries, then stuff a radio in many layers of steel.

    If you are looking for legitimate information in a time of crisis, I would put a satellite phone in the largest Faraday cage I could possibly build, and keep a few years of payment current through a reliable company on the other side of the earth... start making contacts and getting phone numbers now for people acrostic the world. Getting reliable info from random people that "heard" something is really just a wet dream if you really think it through, unless you are thinking local contacts, in which case there are no other radios to be heard anyways.
     
  11. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    In the event of an EMP attack do you really think a satellite phone will be usefull with the satellites being the first thing to be taken out during an attack?
     
  12. 338_MtRushmore

    338_MtRushmore Well-Known Member

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    No force on earth has the ability to take out satellites in every hemisphere with one blast. The shear size of the blast would kill every human on earth. Now back to reason... there would still be plenty of satellites in orbit that were far enough away, or shielded by the earth itself. There very well may be a several hour period without service, but i would be ok with 16 hours of service.
     
  13. Robb

    Robb Yup

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    I don't think you quite understand the concept of emp - or 'electromagnetic pulse'.

    Here's a quickie: When a nuclear blast happens, one of the side effects - besides extreme heat, x-rays, gamma rays, and radioactive fallout - is a extremely large voltage pulse. This immense swarm of free electrons move towards ground in all directions relative to the horizon. It can affect electronics for thousands of miles from the actual blast - depending on the power of the nuke device. The higher up the blast occurs; the wider the horizon. The net effect is fried IC's, transistors, and diodes. So, satellites and computers and anything else in a given range will be toast. End of story.

    https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse
     
    #13 Robb, Feb 17, 2017
    Last edited: Feb 17, 2017
  14. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Speaking of reason.......you should make yourself aware of just how many satellites are actually capable of supporting civilian sat comms. I'll give you a head start. Think INMARSAT and Iridium. INMARSAT has twelve sats in geostationary orbit and Iridium has 66 in low earth non-synchronise orbit. In the event of a large EMP you can bet many will be lost and the others will undoubtedly be commanded to reject low or non priority calls from the civilian population. That can be done based on the users account similar to the way cell towers can reject non governmental accounts or relief agancies in the event of a major disaster if the system is programmed for it.
     
  15. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Even solar storms have taken out many satellites. I remember losing all our news feeds one morning and getting into the newsroom found the satellite receivers had lost signal lock. I called Broadcast News in Toronto and they told me Telesat Canada had lost two Anik birds. Literally lost them. The onboard gyros got fried and they tumbled out of their orbital positions. One was eventually found and repositioned but it's lifespan was drastically reduced due to the constant need for activating the positioning rockets to keep it in place.
     
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