Just occurred to me that the humble microwave should be a fairly effective Faraday cage, certainly for the microwave spectrum, anyone know how good it is for the relevant communication frequencies?
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I just tossed my phone in there and I still got a signal.
It’s actually super easy to build a simple cage. Just put whatever in a box, wrap the box in foil, then a thin cloth, then another layer of foil.
if you want something a little more convenient, they also sell faraday bags for phones and laptops.
Ahh - the ever ambiguous “they.”
/s
Relevant classic StackOverflow-thread: https://stackoverflow.com/questions/7026251/simulate-low-network-connectivity-for-android
Stick your phone in it and test:
Make a phone call to it and see if it rings.
See if it remains connected to WiFi and data.
See if Bluetooth can be connected.
Considering the amount of outside interference it causes, I don’t think it’s as effective as a true Faraday cage, though.
Many microwaves suck as faraday cages, because they are made to be an effective cage only for a very specific frequency (the one the microwave runs at). Unfortunately, mobile radio frequencies are all over the place, for historic, technical, competition etc. reasons. So it is not a good Faraday cage, unless you want to only block out a specific radio (usually, 2.4 GHz Wifi and Bluetooth should be blocked).
You can build a good, vhf to multi-gigahertz frequencies cage by using a metal box and covering all the gaps, cracks etc. in tinfoil or copper tape. Bonus points for grounding. I made a decent one (for some unrelated radio experiments) out of a metal box and a tin foil seal, -60 dB at 2.4 GHz and no reason why it wouldn’t work at other frequencies.
Good enough that Snowden mentioned it in an interview, IIRC. Just uhh, don’t forget about it and turn the microwave on later
I mean if you want to get really serious about protection… do turn it on?
I use a tin container from some cookies at work and as soon as the lid is placed on I know that the device immediately loses Bluetooth and wifi connectivity. Pretty easy solution, a lot more compact and safe than a microwave!
