emp

[outlander]

This is for all the military persons on here:
I was watching a show on the history channel about NORAD and started wondering if the steel body of a jeep would act as a Faraday cage in the event of a nuclear blast with electro-magnetic pulse?

No I'm not paranoid just curious.

[ponyracer1]

If your close enough to see a nuclear blast, you have bigger problems than EMP.........

[XJ88User]

I don't think just military could answer this, anyone with experience in electronics or electrical theory can give you an idea on how a Faraday cage works, and apply that to your desired effect.
Well a car is a very rudimentary Faraday cage. But the gaps in a Faraday cage would be tuned to the wave lengths you would want to screen out of effecting the inside, the smaller the holes in your cage the higher the frequency filtered, the best would be a totally enclosed room. An example of shielding a wavelength is in your microwave, the high frequency microwaves can not pass thought the screen that is used in the door of the microwave, but visible light, a lower energy wave passes through. For EMP your talking a short duration (nearly a spike of energy), high potential blast, that means small holes or none, most people building EMP resistant devices use none. The windows in the XJ or any vehicle for that matter would render the Faraday effect of a vehicle useless to the EMP effect.
But I have to agree with If your close enough to see a nuclear blast, you have bigger problems than EMP......... , even if you don’t see the blast but see the effects of EMP, you have much more to worry about.

[RichP]

But I have to agree with , even if you don’t see the blast but see the effects of EMP, you have much more to worry about.

Qualifer, they have various vehicle disabeling systems that are being tested, one is remote controlled oversized slot car that can be released from a pursuing vehicle and emit an emp burst under the car, the other one is like the tire spike machine, roll out across the street and it fires off an emp burst as the car rolls over it. Bothe wipe the electronics out.
Military has emp devices that can be deployed a variety of ways up to an including a 1 or 2 megaton burst at 20 miles up. Some military vehicles are hardened against this and on some bases you will actually find an EMP test ring, I know of 4 in the NJ/PA area including one at marconi off rt21 near rutherford. They are fairly obvious, bigger than the stargate but with no funny symbols or rotating ring :D

[outlander]

hmmm.What exactely would get fried by EMP?Everything electrical?Or just the computer?

[5-90]

Most solid-state electronics don't care for EMP - as I recall, the massive magnetic pulse induces a current on circuit board traces and in wiring, which "blows holes" in the substrate of anything solid-state or semiconductor-based.

I've actually been kicking something around, I'd like to figure out how to come up with a HIGHLY DIRECTIONAL EMP or HERF generator to blow cellphones of people "DWY" (Driving While Yakking.)

I saw an interesting article in the paper on the subject, wherein it is shown that driving while on the 'phone is equivalent to driving with a BAC of .08% - over the legal threshhold for intoxication. The cognition required to maintain a conversation over the phone is sufficient distraction to make it substantially the same as driving while intox., but DWI is illegal, while DWY is still legal in most places (didn't they get a law passed somewhere in NY, or NYS proper?)

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[87manche]

most anything that is a small circuit. You can bet that EMP would likely take out the ECU and the ignition system.
The Renix ECU might live, because it seems to be shielded like a tank and has far less small surface mount components, but I'd be willing to bet that the ignition system would be toasted. It all really depends if the Jeep was running or not.

[87manche]

Most solid-state electronics don't care for EMP - as I recall, the massive magnetic pulse induces a current on circuit board traces and in wiring, which "blows holes" in the substrate of anything solid-state or semiconductor-based.

I've actually been kicking something around, I'd like to figure out how to come up with a HIGHLY DIRECTIONAL EMP or HERF generator to blow cellphones of people "DWY" (Driving While Yakking.)

I saw an interesting article in the paper on the subject, wherein it is shown that driving while on the 'phone is equivalent to driving with a BAC of .08% - over the legal threshhold for intoxication. The cognition required to maintain a conversation over the phone is sufficient distraction to make it substantially the same as driving while intox., but DWI is illegal, while DWY is still legal in most places (didn't they get a law passed somewhere in NY, or NYS proper?)

5-90
You don't need EMP for that, just a microwave emitter tuned to the cell tower frequencies.
Such things exist and they're used in buildings that people aren't allowed to use cell phones in. For the most part they're illegal due to interfering with emergency services comms.
You could likely make a directional version with the output tied to a computer networking directional antenna. They frequencies are close enough that it should work, you might not get all of the advertised gain of the antenna though because you're outside of what it was tuned for.

[5-90]

You don't need EMP for that, just a microwave emitter tuned to the cell tower frequencies.
Such things exist and they're used in buildings that people aren't allowed to use cell phones in. For the most part they're illegal due to interfering with emergency services comms.
You could likely make a directional version with the output tied to a computer networking directional antenna. They frequencies are close enough that it should work, you might not get all of the advertised gain of the antenna though because you're outside of what it was tuned for.

A thought - but I don't want to "jam" the 'phone - I want to TAKE IT OUT before the drivers TAKES ME OUT.

For the directional antenna, I'd actually been considering a small parabolic dish - even a Yagi would have too much "side bleed..."

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[outlander]

Man you guys a scaring me!

[5-90]

Well, let's see...

About once a week, I get damn near sideswiped by some "yack-ass" on the 'phone while he's behind the wheel...

Both of my boys, while learning to drive, were hit by some damn fool who was DWY...

My wife reports to me, about once every month or so - without fail - some dome fool is DWY and did something dangerous...

I think it's fair. Either that, or pass a law saying that if you're DWY for more than, say, thirty seconds (long enough to say "I'm driving - can I call you back?") you get your license suspended for a year, and you can take Transit and yap to your heart's content. Second offense? Three years. Third offense? You don't get it back.

I'm just tired of self-centred Yuppie yammerheads treating the roadway like it's their personal office, and endangering other people. I've long said that "If you want to die of the dumbs, go ahead. Don't take anyone else with you."

Is that so wrong?

5-90

Oh - forgot. The TOP TWO "distraction" codes on CHP Incident Reports are "Cell Phone - Handheld" and "Cell Phone - Handsfree." But no-one sees the correlation here... I think the last revision on this form was about TEN YEARS AGO, which tells you just how long this sort of thing has been going on...

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[aroncull]

OK so yeah i am a survivalist in general, and have researched alot of different topics this bieng one of them.

That said i do not have any religous affiliations and am a daoist.. so here is a link to a christain end times web site that covers ALOT of awesome things..

All i can say is google is your friend , searching will serve you well..

google search topic terms: "faraday cages emp cars grounding"

http://www.endtimesreport.com
http://www.endtimesreport.com/evac_plan.html

The only real piece i can currently find there is that you can ground your vehicle to reduce EMP effects.. also dragging a chain from your vehicle will sapposedly do the same thing: provide a ground..

Interesting concept anyways... dont think i would like to have chain dragged around behind you but it would liely keep people from following too close LOL.

Aaron

[87manche]

A thought - but I don't want to "jam" the 'phone - I want to TAKE IT OUT before the drivers TAKES ME OUT.

For the directional antenna, I'd actually been considering a small parabolic dish - even a Yagi would have too much "side bleed..."

5-90
Ok I follow you, so you want to actually toast it. That might be accomplished with a focused gunn diode. of course that might also cook their brains too. EMP is something that's hard to successfully power. I imagine that you would need a substantial bank of caps to get a burst that's capable of doing damage. A imple parabolic reflector would work nicely to direct it though.

[Nevada City Sparky]

The Renix ECU might live, because it seems to be shielded like a tank and has far less small surface mount components, but I'd be willing to bet that the ignition system would be toasted. It all really depends if the Jeep was running or not.
Cool! Then all I need for my '89 is a lead shield for the ignition module, and perhaps one for the TCU. Then I'll have a Tempest Cherokee! (Tempest is what they call nuclear hardened computers)

[XJ88User]

First off, sorry this got longer than i wanted it to.

Anyone that really cares 5-90 is very correct, broad based but correct. Think of an EMP pulse as a an ignition coil that suddenly has only the energy and no physical way to ground, it's not coupled to anything it just discharged everywhere in all directions. If you standing close enough you get to be an antenna and you get to absorb the energy at your wavelength. Remember everything has a wavelength, everything.
Most solid-state electronics don't care for EMP - as I recall, the massive magnetic pulse induces a current on circuit board traces and in wiring, which "blows holes" in the substrate of anything solid-state or semiconductor-based.
5-90

Close but no prize, the wire would act like antenna and may transmit enough power or provide enough of a current sink to kill the electronics inside. Most hardened equipment is optically isolated, has isolation transformers to separate the power coils to the supply coils, effectively providing no path to the interior of the cage. Powered or not an EMP blast from a bomb distributes enough power to turn things "on" or bias them until they get destroyed.
most anything that is a small circuit. You can bet that EMP would likely take out the ECU and the ignition system.
The Renix ECU might live, because it seems to be shielded like a tank and has far less small surface mount components, but I'd be willing to bet that the ignition system would be toasted. It all really depends if the Jeep was running or not.

Tempest is for emissions from when the equipment runs so others can not see the signatures of the emissions, it "might" have the effect of helping from en EMP pulse. Lead is for radiation mostly, but it does conduct okay as well.
Cool! Then all I need for my '89 is a lead shield for the ignition module, and perhaps one for the TCU. Then I'll have a Tempest Cherokee! (Tempest is what they call nuclear hardened computers)

Faraday cage's do not have to be grounded or "earthed" as some say, the Faraday cage has to be able to spread the charge out over the skin on the cage, and not transmit that charge to the interior, solid cages do this best.
Lighting might not care about your windows in your car, but then if your car is not grounded it floats, and has no real potential, the chain might actually hurt you in this case, duuno. A EMP pulse wont slow down going thourgh your windows, windows are just holes to it, a chain means someplace your coupled to the base charge of the blast, and the blast is not coupled to ground in the classic sense. If you want to make a Faraday cage out of a car, get solid steal windows, blast shields. The EMP pulse has way to many wave lengths, to much power, and your way to close if you can see any of the effects.

The only real piece I can currently find there is that you can ground your vehicle to reduce EMP effects.. also dragging a chain from your vehicle will supposedly do the same thing: provide a ground..

Interesting concept anyways... don't think I would like to have chain dragged around behind you but it would likely keep people from following too close LOL.

Aaron

All I can say is that's really neat RichP. I got to go look for pictures of those things.
:D

[falcon556]

This is for all the military persons on here:
I was watching a show on the history channel about NORAD and started wondering if the steel body of a jeep would act as a Faraday cage in the event of a nuclear blast with electro-magnetic pulse?

No I'm not paranoid just curious.

The Discovery Channel has a program called "Future Weapons"
On one episode they had an EMP generator and a car nearby. When the EMP was activated, the car died. The windows worked but not the electronics.
They said that 1 nuke very high in space would send the US in the dark ages.
After WWII one nuke test in the Pacific affected Hawaii long distance away.
I think the only way to have a car after an EMP incident would be point and coil ignition.
What was the last year the XJ had points in the 4.0? :-)

[5-90]

XJ88 -
No trouble - I'd figured on being corrected somewhat. When my information is not solid, I usually put qualifiers in my post - "as I recall" is a flag...

So, what you're saying is the destructive effects of EMP are not so much caused by current induced after the magnetic pulse (which made sense to me...) but by the HFRF energy picked up by the conductors? Still makes sense - just using a different theory.

As far as was commented elsewhere - "TEMPEST" is a division of EMSEC - EMissions SECurity - where any signature emissions of equipment is kept to a minimum by shielding. TEMPEST is a means of signature reduction, not electronics protection.

"Hardening" is protection from EMP/HERF, but has nothing to do with emissions.

A piece of equipment may be TEMPEST but not Hardened - the reverse is also true. Also, a piece of equipment may be TEMPEST-shielded AND hardened, because a lot of principles are actually similar.

Also, "Hardening" electronics is not as simple as a lead shield - because "Hardening" has very little to do with ionising radiation (Gamma rays - what lead helps to protect you against.) I'd have to look up what hardening actually does, but ionising radiation, I think, has rather little effect on electronics (while EMP/HERF plays Hell with them.)

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[XJ88User]

EMP represent a hugh potential of electromagnetic energy, more than you might think when a bomb goes of, if it was made for that porpose and detonated correctly.
This is why i said you were correct in a broad sence, the pulse is a mix of HF noise with hugh potential, these wavelengths come from the fission particals as they break down and eject fragments of the base fuel. If you ever get to see an EMP pulse it looks more like a ringing effect on a bad latch curcuit, it's a very bad represenitive of a wave as waves go.
This magnetic pulse travel at diffrent efficencies through the air, then when it comes in contact with a suitable conductor with the correct length to be an antenna, it convers back from a whatever wave it was into a current that is looking for a lesser potental (a ground to it), sort of like lightning, this is also a poor analogy.
You had it correct in your thinking of it, just there was a few steps that I needed to interject for the porposes of this descution. There are lot more steps in the generation of the energy at the electron level to do all it does, but i realy don't think we need that level of detail, because this is boaring enough i'm sure for most of the people here.

In less words these convertion and transmitions of energy below all happen, just in steps, with in a fraction of a second.
XJ88 -
No trouble - I'd figured on being corrected somewhat. When my information is not solid, I usually put qualifiers in my post - "as I recall" is a flag...

So, what you're saying is the destructive effects of EMP are not so much caused by current induced after the magnetic pulse (which made sense to me...) but by the HFRF energy picked up by the conductors? Still makes sense - just using a different theory.

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