[rubylark]

That's interesting! As far as improvised faraday cages go, I always heard that microwave ovens are a good solution. Does this mean that microwave ovens wouldn't be any better as they would only block the specific microwave frequency they're designed for?

[londons_explore]

Correct. In fact, you can easily verify this by putting a phone in an unpowered microwave and calling it. It'll usually get both 4G (frequencies range, but 800Mhz in my area) and Wifi (over 5GHz).