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!
this post was submitted on 26 Jul 2025
45 points (100.0% liked)
Privacy
3330 readers
6 users here now
Welcome! This is a community for all those who are interested in protecting their privacy.
Rules
PS: Don't be a smartass and try to game the system, we'll know if you're breaking the rules when we see it!
- Be civil and no prejudice
- Don't promote big-tech software
- No apathy and defeatism for privacy (i.e. "They already have my data, why bother?")
- No reposting of news that was already posted
- No crypto, blockchain, NFTs
- No Xitter links (if absolutely necessary, use xcancel)
Related communities:
Some of these are only vaguely related, but great communities.
- !opensource@programming.dev
- !selfhosting@slrpnk.net / !selfhosted@lemmy.world
- !piracy@lemmy.dbzer0.com
- !drm@lemmy.dbzer0.com
founded 8 months ago
MODERATORS
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.
Will it keep the brain control waves out too?
Only when it's on.
I guess we need to try. Any volunteers?
Remember, the door must be fully closed :)
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?
Just make sure your fire extinguisher is nearby & is rated for lithium fires.
Please do not the magic smoke
But then it loses the magic...
It becomes more magic!
Usually I put food in the microwave before I turn it on
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.
Considering there's a thing emitting at 800-1000W in there I would say they are pretty effective faraday cages.
I've never had any interferences.
I played online games with some people who mentioned their wifi signal drops whenever someone operates the microwave in the kitchen. (Also, other people had problems when certain old neon lights next to their room were on.)
I've never had that problem, a few minutes ago I tried to make a call and put the phone in the microwave, the moment I closed the door it cut the call.
I'd be worried if I had a leaky microwave.
I've never had any interferences.
All my microwaves in the last 20 years cause interference from several rooms away! Like Bluetooth headsets dropping signal.
I have a device that measures radiation and EMF, and that thing spikes when the microwave is on, too. 😮
I hope OP does this and reports back.
Someone else recommended a tin cookie jar.
I'd like to hear results on all types* of connectivity, at least the three you mentioned. Maybe start a logger on the phone before you put it in.
* telephony, GPS...
I wonder if a cast iron crock pot would work, too. Those are dirt cheap second hand. They weigh a ton, though 😞
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 (I used a tea towel), 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
For science! Good to know (how did you tell with the door closed? text it or something?).
I used the mobile hotspot feature. My internet speeds were very slightly slower, but barely any different, so it clearly leaks a lot.
On mine the call got cut as soon as I closed the door.
A while back I used one of these Ubertooth Ones: https://greatscottgadgets.com/ubertoothone/
It could measure and plot signal in the 2.4G spectrum for both Bluetooth and WiFi. One time, my wife tossed a burrito in the microwave. The spectrum chart went nuts. White noise.
Unless microwave shielding has greatly changed, there's a lot of leakage. You're better off getting one of those shield pouches off Amazon or AliExpress.
So many people with busted microwaves.