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Comment by labster | Hacker News Reader

Just put it in a Faraday cage. Problem solved.

>> That was a fun night when the dead phone woke up and started dialling 112 repeatedly and there was nothing I could do short of smashing the damn thing with a hammer to stop it.

> Just put it in a Faraday cage. Problem solved.

Even if I don't have a hammer handy, I could probably find something in the middle of the night to smash the thing. A Faraday cage on the other hand...

Not sure your kitchen situation, but most homes have a microwave. Shouldn't that work?

There are many frequency bands used by phone, I'm not sure everything is blocked by microwave.

I tested this. My phone does indeed have a network connection in the microwave.

Tried that. Didn't work.

Do I need to turn on the microwave with the phone inside it? This is an honest question because I don't know anything about microwave signals (I could google/research), but my instinct tells me I probably shouldn't turn on the microwave with the phone inside it, though I don't know for sure what will happen (explode?)

Don't microwave electronics

Never. Never. https://www.youtube.com/watch?v=BAImzF2fYOs

No, a Faraday cage does not require power (just grounding).

Grounding is not necessary in this case, where we are dealing with EM radiation, not static charges.

Why would it need grounding? Are you thinking of static electricity?

What about tin foil?

I wonder if it shouldn't be a thing we keep handy. Like a foldable Faraday cage (bag ?) big enough to fit a laptop that can be whiped out in case of emergency.

They definitely make Faraday cage bags that are about as thick as heavy mil trash bags. Depending on the issue (EMP?) you may need to double bag if primitive YouTube experiments are anything to go by (basically, does the phone ring/radio receive once it's enclosed).

I wonder if a microwave is a sufficient Faraday cage to kill cell reception

They did quite well for 3G and even 4G which didn't have as many above 2.4GHz , but after 4GLTE, 5G has added a lot of mid-bands between 2.6-6GHz. Those tend to leak more since they have shorter wavelengths than microwaves are built around 2.4GHz. Some of them are only used in a few countries, but n2 & n77 are widely used by ATT.

https://en.wikipedia.org/wiki/LTE_frequency_bands

https://en.wikipedia.org/wiki/5G_NR_frequency_bands

You gotta take that phone out sometime though to heat up your ramen.

4GLTE/5G compatible microwave is needed!

Usually. You can check by putting your phone in and closing the door while looking at the signal strength meter. It should go without saying don’t turn the microwave oven on with your expensive electronics inside. If you get decent reception in the closed oven, you need a new one.

Definitely works to kill reception forever if you power up the microwave for a couple of minutes…

You may just need to clean the inside of the door so it closes better. Try that first.

"you need a new one." <-- New microwave, I presume?

One of the things I remember from the Snowden reporting is that he had the reporters use a freezer as a Faraday cage for their phones.

No, they used it as acoustic insulation for the microphones and optical insulation for the cameras. The signal blocking, if any, is just a bonus, but isn't to be relied upon.

Talk about a cold reception.

Or a biscuit tin.

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