Dr. Arthur Bradley walks through the testing of metal garbage cans and anti-static bags against a RF energy from an EMP. Recommendations include how to properly seal the cans and which bags offer best protection. Using a more scientific approach than “stick a radio in the trash can and see if it loses signal” this is some great information.
I would recommend watching the video at some point over on YouTube and read through the comments. Dr. Bradley responds to many comments and answers questions. Good additional information there.