Serious question about my homemade Faraday cage experiment

I built a Faraday cage out of a steel trash can and copper mesh last month to test if it would block my phone signal. I put my old Samsung Galaxy S9 inside and called it from my house phone, and it rang clear as day. Then I wrapped the whole thing in aluminum foil and tried again, and this time the call dropped at 7 feet from the cage. Did I learn that the foil layer does something the mesh doesn't for RF blocking, or did I mess up the grounding somehow? Has anyone else gotten weird results trying to DIY these things?

3 comments

3 Comments

irisowens6d ago

Yeah that whole thing about grounding closing the gaps rings SO true. @michaelgrant is right, it's like how people think locking their front door is enough but you gotta check the basement window too. Same with life, you think you've got one side handled and something else slips through.

pat7814d ago

Huh, never thought of it that way but @irisowens you and michael totally changed my mind on this one.

michaelgrant6d ago

Did you ground the cage to an actual earth ground or just let it sit on the floor? When I built my own from a metal filing cabinet I had the same issue until I ran a wire from the cage to a copper pipe in my basement, then suddenly my phone stopped ringing inside every time. My guess is the foil closed some gaps the mesh was leaving open, but I bet proper grounding would fix your weird results either way.