How do Signal Blockers Work? (Faraday Cages)
Techquickie
·Techquickie
·2018-05-06
·
898 words · ~4 min read
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you know as much as i love tech i still marvel at how some of the most advanced
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complicated devices ever invented can be
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defeated by crude simple instruments and
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perhaps nothing demonstrates this idea better than the faraday cage essentially
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a metal container that blocks wireless signals
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but wait a minute Linus metal i mean it kind of makes sense to me why
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thick concrete is bad for your cell signal but wouldn't metal just like
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conduct electricity well okay of course yes it does which is
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why you shouldn't stand outside with a festivus pool during a thunderstorm but
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that doesn't mean that metal will allow radio waves to pass through it you see a
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faraday cage works because radio waves move through electric fields which
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interact with the charges that are naturally present in metal electric
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fields push positive charges away from them meaning that when they hit a
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faraday cage negative charge collects on the side of the cage nearest the signal
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source while positive charge accumulates on the other side because the incoming
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field is oriented in a positive to negative direction now since the charges
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in the metal have now oriented themselves in the opposite direction
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they produce their own electric field going the other way meaning that they
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cancel each other out inside the cage and the radio waves can't pass through
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it the simplicity with which a faraday cage can be constructed has led them to
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appear in plenty of electronic applications notably in microwave ovens
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where they keep radiation from leaking out into your kitchen and turning you
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into a human hot pocket you've probably also seen smaller
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faraday cages for sale in the form of rfid blockers which purport to shield
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your credit cards from attackers who might try to steal information off of
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them with scanners and although it's actually pretty difficult for identity
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thieves to use this information as the rfid chips inside of cards don't contain
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enough information on their own to do much real damage the market for these
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protective sleeves and wallets is thriving nonetheless
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another less obvious example is the metal layer commonly found inside the
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cables for your electronics these serve as a shield around the
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copper wire that actually transmits the signal this shield is effectively a
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tubular faraday cage that keeps external signals from getting into the wire and
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screwing up your content as well as preventing its own signals from escaping
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and interfering with your other wires and gadgets and one of the coolest things about
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faraday cages is that due to their simplicity there are some really
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interesting diy applications some folks out of concern for their
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personal privacy for example will keep their cell phone in a metal container
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while charging also uk police have advised people with
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wireless ignition systems to keep their keys in a similar enclosure to prevent
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what's called relay car theft where thieves read the signal off of your key
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fob from outside the house start your car and then drive away
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and another common use is wannabe criminals lining their shopping bags or
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pockets with foil to try to prevent the rfid tags on stolen items from setting
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off alarms when they leave the store though before you run out and try that
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one many retailers are wise to this technique and have
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installed metal detectors to defeat these so-called booster bags
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on that note if you're building your own for whatever reason faraday cages can't
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shut everything out and it should be noted that any holes in the cage need to
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be smaller than the signal wavelength to attenuate outside broadcasts so in some
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situations one phone might work inside a faraday
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cage while another one might not due to different carriers using different
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frequencies this is something that you may have noticed in nature's
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unintentional faraday cage the metal elevator so we recommend a more
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purpose-built solution for your faraday cage needs kfc of all companies is
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offering a faraday tent that it calls the internet escape pod for the low
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price of what five thousand dollars
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why do they even sell this what are they even
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i mean at that price i hope it at least comes
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with extra gravy synergy ii is designed to be easier and
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more seamless to use than synergy one synergy is a mouse and keyboard sharing
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software that works on Windows mac and Linux computers with features like being
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able to share from anywhere so you can automatically control any other computer
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without reconfiguring ssl encryption to protect your keystrokes from attackers
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dynamic networking which intelligently detects the best route based on your
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networking setup and the ability to always run in the background on all
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operating systems so you can just set and forget it if you get the pro version
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you can even get access to other cool features like clipboard sharing dragging
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and dropping files copy pasting lock screen synchronization and tons more so
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get 50 off synergy 2 today at the link in the video description so thanks for
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watching guys if you disliked this video you can hit that button but otherwise
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hit like get subscribed check out our other channels and leave a comment if you have suggestions for future fastest
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