
How to Make a Handheld EMP Jammer - adius
http://hackaday.com/2016/10/12/become-very-unpopular-very-fast-with-this-diy-emp-generator/
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M_Grey
Or, "How to kill people with pacemakers". Seriously, there are a lot of bad
uses for this which have nothing to do with phones.

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subliminalpanda
Or one of those going off on a plane. Horrible consequences.

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Sanddancer
You'd need a lot more current in order to cause horrible consequences for an
airplane. Lots of redundant systems, lots of testing for electromagnetic
tolerance.

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tcas
This is what a setup for testing airplanes for EMP tolerance looks like:
[https://en.wikipedia.org/wiki/ATLAS-I](https://en.wikipedia.org/wiki/ATLAS-I)
Note that this isn't used anymore.

And here's an anechoic chamber for testing military craft:
[https://en.wikipedia.org/wiki/Benefield_Anechoic_Facility](https://en.wikipedia.org/wiki/Benefield_Anechoic_Facility)

Now I'm curious to see an A380 in an anechoic chamber... Are full airplanes
normally tested in a chamber? Or only the individual systems?

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eternauta3k
Why do you need a chamber?

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madengr
Fully anechoic chambers are for antenna pattern testing and scenario testing
where you don't want reflections; you want to simulate free space such as
planes in the air.

Semi-anechoic is for electromagnetic compliance testing. They have absorber on
walls but not floor. Typically don't want signals to get out. Bare floor sort
of mimics earth, as ground plane can guide wave.

Some chambers are fully reflective with mode stirrers, but those are
specifically for EM susceptibility testing.

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jacquesm
This won't destroy your phone. Phones are extensively tested when it comes to
both creating and withstanding EM interference. Best it could do - maybe - is
crash one that is on the edge of its spec and you would probably have to get
pretty close for that (fall off as the square (edited) of the distance).

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blacksmith_tb
Shouldn't the signal fall off with the square of the distance (inverse-square
law)?

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mSparks
aiui.

its not linear.

either it induces a voltage high enough to cause disruption or it doesnt.

the limiting factor is the voltage not the power (power is tiny)

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mSparks
and what i mean by that, is we are talking about a pulse of high voltage and
very very high frequency (maybe even gamma radiation) and its effect on
electronics.

thats not a case of power falloff. Because interaction with the environment
and target is non linear.

for example if it blasts a phone to reset from a few centimeters it could
easily drop all calls in a 20 meter radius. but upping the power/voltage 4
times may only add milimeters to the range of blasting the phone to reset
because so much is absorbed by the case. but upping the power/voltage 5 times
could add a meter to blasting the phone to reset because the case now no
longer absorbs enough energy to prevent the interference. Also resonance and
harmonics play a huge role in the effect.

All conjecture. but my point is you cant apply school boy physics to the
problem because its not a problem they teach in school.

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madengr
Just to clarify after seeing several posts below. The magnetic and electric
near fields fall off from 1/r^3 to 1/r^2, depending on component. The far
fields fall off at 1/r, hence the familiar 1/r^2 for power (not amplitude).

[http://www.rfcafe.com/references/electrical/near-far-
field.h...](http://www.rfcafe.com/references/electrical/near-far-field.htm)

This thing operates in the near field, so it is pretty much useless past a
distance of a coil diameter.

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Hasz
If you wanted to do this right, you'd match the impedance to the antennae
impedance of a typical phone antennae.

This gets around the square rule, sort of, and you won't need a suitcase full
of batteries to power the thing.

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tlarkworthy
Things like that were used to cheat slot machines [http://empjammer.com/how-a-
emp-jammer-working](http://empjammer.com/how-a-emp-jammer-working)

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jacquesm
Much cheaper to use an electric gas lighter.

That's what we used to test on stuff that was supposed to be reliable and it
is amazing how hard it is to defend against it. If you could survive 10
seconds or more without a latch losing state or some other bitflip then it was
usually a pretty good job. Even so, this required physical contact to
something made of metal on the machine (even if most of it is properly
grounded there always is some exposed metal that isn't).

I hope the engineering on that product is better than the English, it is
barely understandable.

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bigiain
Heh - showing my age here, but I remember using gas lighters (stolen from
school heaters) to zap free game credits into Asteroids machines...

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ars
What did you do? Just heat it up till it does "something"?

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bigiain
Just zap some of the metal around the coin slot until it either crashed or
gave you free games.

(These were the piezo spark-ignitors, not pilot flames...)

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phkahler
I've often thought about using a wok as a dish and putting a magnetron at the
focus. High power directed microwaves would probably damage a lot of things.
And made from kitchen hardware...

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Thorondor
Probably safer to let somebody else try this... ;) A couple of Ukrainians made
a cool YouTube video recently where they built something similar and used it
to blow up some cell phones.
[https://www.youtube.com/watch?v=FIU8WZR9DNA](https://www.youtube.com/watch?v=FIU8WZR9DNA)

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ars
They seem to have absolutely no sense of self preservation.

Can they really expose their hand to that (below the temperate at which they
get a burn) with no internal/hidden damage whatsoever?

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zeroer
It's not ionizing radiation, so the only damage is from the heat. So they
probably can expose their hand without damage.

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pdkl95
Just because it's non-ionizing doesn't mean it's safe. HERF will simply _cook_
you, and just like your kitchen microwave oven it will cook the strongest at
the antinodes. This means you can get _very_ nasty burns _inside_ your hand
that don't show on the surface.

Just being near some antennas when it is transmitting can give you a very
nasty RF burn. A magnetron that can damage electronics (or cause almost any
visible effect) is going to do you what it does to your food.

Seriously, don't mess with high-energy RF without proper safety training.
Waving around an open magnetron that could be reflecting back at you in
unknown ways is incredibly dangerous.

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georgeecollins
This seems like a device that is possible to cause a lithium battery fire
because of the discharge rate.

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pervycreeper
What component is failing in order to cause that iphone's screen to fade out
in that way?

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giardini
Why a second external coil? It isn't aligned with the first coil and so the
induced EMF is minimized (usually such coils are co-axial).

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jwildeboer
It doesn't destroy phones, though. It resets them at max according to the
video and tests.

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madengr
Funny he can build an EMP generator but can't properly bias an LED.

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viggity
this reminds me of a coworker who tried to create a tiny DC motor with a
battery, a magnet, and _non-enameled_ wire. yeah, that didn't work out too
well for him. I tried to explain why the wire needed to be enameled, but the
cargo-cult science was strong with him.

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jaytaylor
How would the design need to be changed to make it possible to zap a phone
from a distance of 1-10 meters?

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kevinconroy
You need 1.21 Gigawatts for that.

(Seriously, though, you'll need to square the power source as you double the
distance.)

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jaytaylor
Does that mean the rest of the system can stay the same? Aassuming minimal
adjustments required to wire gauge as power increases.

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smoyer
Sweet! ... My EMP generator only works on Samsung Galaxy Note 7s!

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mcguire
" _18650 lithium battery cell_ "

Or, possibly, explode into flaming death.

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mcguire
Ok, so let me put it another way: how much resistance does that circuit have?

