Testing a Trash Can Faraday Cage(www.jefftk.com)
3 pointsby torutofuan hour ago1 comment
  • schiffern32 minutes ago

      >The initial pulse ("E1") is very short and the voltage it induces is proportional to the length of the conductor it hits. The power grid (famously involving long conductors) would be seriously damaged, especially the massive and hard to replace transformers.
    It's mostly the E3 pulse (seconds to minutes) that causes a slow rise in grid voltage which blows those big beefy transformers.

    Dr Arthur Bradly is a great resource on this. His day job is testing/troubleshooting EMI for NASA space probes, but I'm grateful he's slumming it in his home lab for us crazy preppers. :)

    https://youtu.be/JNBj3nkVqEQ

    https://youtu.be/aMct99DiZak

    • schiffern3 minutes ago
      Regarding the Oscar the Grouch trash can, the gap (which usually changes every time you remove and replace the lid, hence the gasket/tape for reliability) is acting as a slot antenna[0]. Small holes are fine, even many small holes, but long slashes will let RF through.

      This is wavelength dependent, hence why your results only show it at high frequency (exactly where EMP hits).

      [0] https://en.wikipedia.org/wiki/Slot_antenna