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Comment by beretguy | Hacker News Reader

Is it possible to wrap “cellular connection” module in copper mesh to cut it off from sending data?

It probably won't work very well. Faraday cages attenuate, they don't block signals, and most amateur attempts don't even attenuate very much.

Wrap your phone in aluminum foil, put it in the microwave, and give it a call. It'll probably still ring.

Tried it -

1. No foil, microwave - rings

2. Foil, no microwave - rings

3. Foil, microwave - doesn't ring

I feel like cell phones have to be more sensitive than w/e transmitter the car has, but your point holds - naively wrapping it in foil still probably won't work.

Cell phones are less sensitive than the transmitter in your car, usually. Think about how much power budget you have in a car vs. A phone.

Nice! I've done a bunch of RF attenuation experiments with friends, and foil+microwave was the best result we found using stuff lying around any of our houses. With foil+microwave we were able to attenuate the signal enough to seriously degrade service, but never quite enough to block all traffic. In our experiments, the microwave was doing the majority of the work, based on the signal strength we observed. Results also varied a good bit by carrier, presumably because of the different bands used.

Tin-foil hat wearers beware.

You probably have better luck by finding some standard antenna connection and attaching a proper 50 Ohm terminator to it.

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