[[[Time to build that Faraday Cage]]]

I'm hitting Sam's club tomorrow to buy a 250 gig backup harddrive for my laptop and wife's pc plan on backing up our files and keeping the backup in my cage, along with a shortwave, internet done GLP just a fond memory for months if not years.

EMPs work by producing enough ambient energy in an electronic circuit
to fry the components, causing sparks to jump around the microscopic
pathways and cook the insides. Generally, the only way to protect
against these things would be for any and all electronic devices to be
inside a Faraday cage. These cages are made of metal which allows for
the charge of the EMP to be conducted around the object instead of
through it.

The easiest way to make one of these would be to use a steel trash can
and insulate the bottom with a non-conductive substance like foam or
wood. By placing any objects on top of this insulator, in theory,
when an EMP charge goes off (even from a lightning bolt) the pulse
will be conducted around the metal of the trash can and not through
the inner contents. On the great show Mythbusters, they have designed
several Faraday cages just using simple mesh metal strung around a
wooden frame.

Of course, like other people have mentioned, you have to consider that
just about anything else above surface will be fried provided that it
hasn't been protected. So the real question is one of what is worth
protecting. Computer hard drives would be one good candidate,
walkie-talkies would be another for just a simple trash can. For
larger structures, you would need to build a bigger cage.

[link to en.wikipedia.org]

Electromagnetic pulse
From Wikipedia, the free encyclopedia
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Example of an electromagnetic pulse, in this case caused by the electrical discharge required to fire the Z machine. Note that electric current is induced in all the metal objects in the room.In telecommunications and warfare, the term electromagnetic pulse (EMP) has the following meanings:

The electromagnetic radiation from an explosion (especially nuclear explosions) or an intensely fluctuating magnetic field caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the electronic or explosive device or in a surrounding medium. The resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges. See Electromagnetic bomb for details on the damages resulting to electronic devices. The effects are usually not noticeable beyond the blast radius unless the device is nuclear or specifically designed to produce an electromagnetic shockwave.
A broadband, high-intensity, short-duration burst of electromagnetic energy.
In the case of a nuclear detonation or a meteor impact[1], the electromagnetic pulse consists of a continuous frequency spectrum. Most of the energy is distributed throughout the lower frequencies between 3 Hz and 30 kHz.

Source: from Federal Standard 1037C in support of MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms

In works of fiction, EMP has made many appearances, particularly in science fiction. In the cyberpunk sub-genre, EMP is often portrayed as a superweapon that distorts social order by destroying technological artifacts central to a society, or as a potent weapon against mechanical or robotic enemies.

For those who haven't heard our discussions on EMP in the past, here's
some basic info. The way to protect devices from EMP is to disconnect
them from any outside lines (like antennas and power lines), and
shield them inside a grounded metal box (known as a Faraday cage).
This can actually be easier than it sounds. I have an old
army-surplus steel desk, and my main shortwave radio (Grundig 4000) is
in its original cardboard box, in one of the drawers. Presto -
reasonably good EMP protection. I should probably wrap the radio in
aluminum foil and make sure the desk is grounded to be really safe.
All my other radio gear, batteries, and battery chargers are in my
retired aluminum work briefcase in my cellar. About the only good
thing you can do for a car is get a detached garage that's a metal
building with no doors or windows. However, there is considerable
speculation on how resistant cars are to EMP type damage, since the
engine compartment itself is a metal box in most cars (although not
completely sealed), and the engine electronics are already designed to
operate in a high-voltage harsh electrical environment.

The things that will suffer most in an EMP attack are communications
equipment, because they typically have antennas or power connections
and are sensitive to small signals. To an electronic device, an EMP
surge is very similar to a lightning-induced electrical surge. You do
have surge protectors on all your computers, TV's, and radios, right?
What about on the telephone lines? The cable lines? I fix computers
for a living and I see more people take lightning damage over the
phone and cable lines than over the power lines. Cyber Power makes a
model 890 surge protector that has phone and cable line protection in
addition to power line protection. They're hard to find on store
shelves, however.

Nobody really knows how much damage an EMP attack will cause. The
power grid is sure to fail for at least some time. This is how they
discovered EMP in the first place years ago: high-altitude nuclear
tests in the Pacific caused the lights to go out suddenly in Hawaii.
The long power transmission lines act like antennas. Car ignition
systems may survive just fine (opinions vary widely on this), but
getting fuel will be a problem since all modern gas stations use
electrically-operated pumps. The military designs all their equipment
to be "EMP-hardened", but it's hard for even them to be sure since the
only way to create a really powerful EMP is with a nuclear weapon, and
we quit testing those some time ago. Other pulse generators exist but
they don't make quite the same type of pulse that nuclear explosions
do. Also, if an attacking nation is really smart, they might use more
than one weapon. Detonate one, wait a day or two until everyone has
pulled out their battery-powered radios, then let go with another one.
It's for this reason that I have both a main and a backup shortwave
radio.

However, preparedness isn't all that hard. If you have older radios,
TV's, or laptop computers you can spare, wrap them in aluminum foil,
then stuff them into a cardboard box, and finally put the box inside a
galvanized metal trash can with a tight-fitting lid, preferably in a
basement or below ground level somehow. Now you will have at least
some gear in the event of an emergency. Of course, you'll also need
batteries to run the equipment! Batteries themselves are probably
immune to EMP, so you can store them elsewhere. More good information
can be found on the internet.

I wrapped my car and my Blues collection in aluminum foil. Is that cool ? If I loose my Blues, I don't want to live anyway.

I got seven hundred dollars
don't you mess with me ...
John Lee Hooker

The worst of the pulse lasts for only a second, but any unprotected electrical equipment — and anything connected to electrical cables, which act as giant lightning rods or antennas, will be affected by the pulse. Older, vacuum tube (valve) based equipment is much less vulnerable to EMP; Soviet cold war era military aircrafts often had avionics based on vacuum tubes. There are a number of websites that explore methods for protecting equipment in the home or business from the effects of an EMP attack.

It is important to note that many nuclear detonations have taken place using bombs dropped by aircraft. The aircraft that delivered the atomic weapons at Hiroshima and Nagasaki did not fall out of the sky due to damage to their electrical or electronic systems. This is simply because electrons (ejected from the air by gamma rays) are stopped quickly in normal (dense) air for bursts below 10 km, so they don't get a chance to be significantly deflected by the Earth's magnetic field (the deflection causes the powerful EMP seen in high altitude bursts), but it does point out the limited use of smaller burst altitudes for widespread EMP.

If the B-29 planes had been within the intense nuclear radiation zone when the bombs exploded over Hiroshima and Nagasaki, then they would have suffered effects from the charge separation (radial) EMP. But this only occurs within the severe blast radius for detonations below about 10 km altitude. EMP disruptions were suffered aboard KC-135 photographic aircraft flying 300 km from the 410 kt Bluegill and 410 kt Kingfish detonations (48 and 95 km burst altitude, respectively) in 1962 [2], but the vital aircraft electronics then were far less sophisticated than today and did not crash the aircraft.

Several major factors control the effectiveness of an EMP weapon. These are:

The height of the weapon when detonated
The yield of the weapon
The distance from the weapon when detonated
Geographical depth or intervening geographical features



[edit]
Weapon height

How the peak EMP on the ground varies with the weapon yield and burst altitude. Note that the yield here is the prompt gamma ray output measured in kilotons. This varies from 0.1-0.5% of the total weapon yield, depending on weapon design. The 1.4 Mt total yield 1962 Starfish Prime test had an output of 0.1%, hence 1.4 kt of prompt gamma rays. (The blue 'pre-ionisation' curve applies to certain types of thermonuclear weapon, where gamma and x-rays from the primary fission stage ionise the atmosphere and make it electrically conductive before the main pulse from the thermonuclear stage. The pre-ionisation in some situations can literally short out part of the final EMP, by allowing a conduction current to immediately oppose the Compton current of electrons.)According to an internet primer published by the Federation of American Scientists[3]

A high-altitude nuclear detonation produces an immediate flux of gamma rays from the nuclear reactions within the device. These photons in turn produce high energy free electrons by Compton scattering at altitudes between (roughly) 20 and 40 km. These electrons are then trapped in the Earth's magnetic field, giving rise to an oscillating electric current. This current is asymmetric in general and gives rise to a rapidly rising radiated electromagnetic field called an electromagnetic pulse (EMP). Because the electrons are trapped essentially simultaneously, a very large electromagnetic source radiates coherently.
The pulse can easily span continent-sized areas, and this radiation can affect systems on land, sea, and air. The first recorded EMP incident accompanied a high-altitude nuclear test over the South Pacific and resulted in power system failures as far away as Hawaii. A large device detonated at 400–500 km (250 to 312 miles) over Kansas would affect all of CONUS. The signal from such an event extends to the visual horizon as seen from the burst point.
Thus, for equipment to be affected, the weapon needs to be above the visual horizon. Because of the nature of the pulse as a large, long, high powered, noisy spike, it is doubtful that there would be much protection if the explosion were seen in the sky just below the tops of hills or mountains. The circumstances inside the bottom of deeper valleys may be different, and locations with a large mountain range in-between (such as the Rocky Mountains) likely have some protection. Thus a weapon detonated high over Kansas might have only indirect effects on the US West Coast.

The height indicated above is greater than that of the International Space Station and many low Earth orbit satellites. Large weapons could have a dramatic impact on satellite operations and communications; smaller weapons have less such potential.

[edit]
Weapon yield
Typical nuclear weapon yields quoted in such scenarios are in the range of 20 megatons. This is roughly 1000 times the sizes of the weapons the United States used in Japan at Hiroshima and Nagasaki.

[edit]
Weapon distance
The major energy in an EMP is electromagnetic, and radiates out from the point of detonation in a sphere. EMP is electromagnetic radiation. The intensity of these fields decreases in proportion to the circumference and distance from explosion. The actual amount of EMP energy deposited per unit area is entirely different, and that falls off as the inverse-square of distance

Painful to live in Fear, isn't it ?

-Leon "Blade Runner"


like this guy is gunna need his laptop when the world ends, some of you are just ridiculous, you know that ?

A Faraday cage is an enclosure designed to exclude electromagnetic fields. It is an application of Gauss's law, one of Maxwell's equations. Gauss's law describes the distribution of electrical charge on a conducting form, such as a sphere, a plane, a torus, etc. Intuitively, since like charges repel each other, charge will "migrate" to the surface of the conducting form. The application is named after physicist Michael Faraday, who built the first Faraday cage in 1836, to demonstrate his finding. Faraday was the experimentalist who described the physical concepts formulated in Maxwell's equations.

Dirty Annie I don't believe the world is going to end but it might get messy real soon, it is only prudent to plan for what may come!and always will be!

Faraday's finding
Faraday stated that the charge on a charged conductor resided only on its exterior, and had no influence on anything enclosed within it. To demonstrate this fact he built a room coated with metal foil, and allowed high-voltage discharges from an electrostatic generator to strike the outside of the room. He used an electroscope to show that there was no electric charge present on the inside of the room's walls.

This shielding effect is used to eliminate the effects of electric fields within a volume, for example to protect electronic equipment from lightning strikes and other electrostatic discharges (ESDs).

The same effect was predicted earlier by Francesco Beccaria (1716–1781) at the University of Turin, a student of Benjamin Franklin's work, who stated that "all electricity goes up to the free surface of the bodies without diffusing in their interior substance". Later, the Belgian physicist Louis Melsens (1814–1886) applied the principle to lightning conductors.

The Faraday cage is sometimes known as a Faraday shield. The latter term is also used more generally for any kind of electrostatic shielding.

[edit]
The idealized Faraday cage
Consider an idealized hollow electrical conductor such as an empty sphere or box.

If the outside of the cage is an idealized conductor, it will form an equipotential surface, that is to say, its surface will have the same electrical potential at every point. If there is no electrical charge inside the box, then by Gauss' law and the divergence theorem, there should be no electrostatic field inside the equipotential surface, regardless of what the field is outside the box.

Since the electrostatic field equations are linear, even field-generating charges in the box will not be affected by any fields outside the box.

[edit]
How a Faraday cage works
A Faraday cage is best understood as an approximation to an ideal hollow conductor. Electric fields produce forces on the charge carriers (usually electrons) within the conductor. As soon as an electric field is applied to the surface of an ideal conductor, it generates a current that causes displacement of charge inside the conductor that cancels the applied field inside.

[edit]
Real-world Faraday cages
Faraday cages are often put to a dual purpose: to block electric fields, as explained above, and to block electromagnetic radiation. The latter application is known as RF shielding.

Practical Faraday cages can be made of a conducting mesh instead of a solid conductor. However, this reduces the cage's effectiveness as an RF shield.

Some real-world structures, such as automobiles, behave similarly to Faraday cages.

If lightning hits near a car, it does not affect the people sitting in the car.
Mobile phones and radios have worsened reception inside a building, vehicle, tunnel, etc.
If artificial lightning is produced inside a mesh of wires, it does not affect the spectators outside.
Some United States national security buildings are contained in Faraday cages, intended to act as a TEMPEST shield, and possibly also as a mitigation against electromagnetic pulse.

Some traditional architectural materials act as Faraday shields in practice. These include plaster with metal lath, and rebar reinforced concrete. These affect the use of cordless phones and wireless networks inside buildings and houses.

The door of a microwave oven has a screen built into the glass of the window. From the perspective of microwaves (with wavelengths of 12 cm) this screen finishes a Faraday cage formed by the oven's metal housing. Visible light, with wavelengths ranging between 400nm and 900nm, passes easily between the wires.

[link to en.wikipedia.org]

As long as you put it in a metal trash can on top of any insulator you can still listen to the blues.

James Taylor Steam Roller Blues

Steamroller Blues
I'm a steamroller Baby
I'm 'bout to roll all over you
I'm a steamroller Baby
I'm 'bout to roll all over you
I'm gonna inject your soul
With some sweet rock'n'roll,
And shoot you full of Rythm and Blues, yeah ..

I'm a napalm-bomb
Guaranteed to blow your mind
I'm a napalm-bomb
Guaranteed to blow your mind
If I can't have your love now Baby
There won't be nothing left behind, yeah ..

( Instrumental )

Mm .. I'm a steamroller Baby
I'm 'bout to roll all over you
I'm a steamroller Baby
I'm 'bout to roll all over you
I'm gonna inject your soul
With some sweet rock'n'roll
And shoot you full of Rhythm and Blues

I'm a napalm-bomb Baby
( napalm-bomb )
Guaranteed to blow your mind
( blow your mind )
I said I'm a napalm-bomb
( napalm-bomb )
Guaranteed to blow your mind
( blow your mind )
If I can't have your love now baby
There won't be nothing left behind
Yeah ..

how far do emp's go into the ground? is a computer in the basement safe?

Why risk it, you can build a workable cage for less than 20 bucks at your local big box store.

Make sure anything used as a Faraday Cage is grounded well by a
wire;
> whether garbage can or file cabinet. Just setting on the floor
is usually
> not considered safe.
>
> I drill and hole and take some sandpaper and make sure the paint
is off
> around the hole and using a small bolt secure a wire that I then
ground to
> an outlet.
>
> Any opening in the container, like holes or slits can allow the
EMP waves
> in, so make sure they are covered by some conductive material.
Metal tape
> (true metal tape, not metal looking or plastic) can be used to
cover any
> openings.
>
> I cut down several boxes and line the inside of anything used as a
cage and
> then make sure what I put in the cage is boxed. Also it helps if
possible
> to remove any cords or wires if possible coming out of the
equipment you are
> storing because they can act as an antenna to bring in the EMP
waves. My
> understanding is even a 2 inch long power cord coming out of a
radio would
> multiply its chance of damage many times. Also make sure
everything has
> their batteries removed and are all switched off.
>
> Worse comes to worse, try putting things in something plastic to
insulate
> them and set them in the metal trunk of ones car. The car is not
grounded,
> but the heavy metal mass is better then nothing. That why
hopefully why
> your car might survive. It wouldn't work if you have a plastic or
> fiberglass trunk ( for example a Corvette ).

For small electronics,radios etc.You can place them in a microwave.Just plug it in to ground it.

It's made to keep microwaves in and will keep EMP out!

Ok, boys and girls, if you see a really bright flash of light, don't look at it, but quickly Duck under your desk and Cover your head, and you'll be just fine.

The world isn't going to end..

And there can be valuable information on those laptops..

;)

Dear God I remember those drills!
Duck And Cover!

[link to www.endtimesreport.com]

The reality of needing to protect all electronic equipment against EMP from a nuclear explosion over our shores is becoming imminent. We now live in perilous times. The world is a becoming dangerous place, with China now threatening Taiwan with annihilation from hundreds of neutron bombs. Russia is modernizing their military infrastructure with an emphasis on first strike capability, they have an stretegic alliance with China, and Putin is exporting "special nuclear materials" to Iran, Syria and Egypt. President Clinton renounced "launch on attack" in favor of absorbing a first strike without retaliation, while President Bush wants "first strike" authority to attack anywhere with nukes without warning, and it is easy to see that our enemies are virtually being invited to hit us with nukes! Iran has plans to do just that!

The information to follow on building "Faraday cages" is timely indeed. A single atmospheric nuclear detonation releases enough electromagnetic pulse (EMP) to equal 100,000 volts per meter (V/m). A single detonation 200 to 400 miles over the center of the continental United States would fry every unprotected computer chip from coast to coast, and from the middle of Canada to the middle of Mexico. And we are now into Solar Cycle 23, with solar flares common and expected to continue until the first of next year. CME's are capable of extreme damage to modern computerized equipment! Sure, we have our windup BayGen radio's and spare lap top computers, but unless electronic equipment is protected from an electromagnetic pulse, they will be fried!


When Einstein and the others first refined and purified uranium, they took time off and studied its properties. That is when they discovered the "rays" that were harmful, as well as the phase transformations. In the course of their work, one of the scientists discovered that simply covering an object with a grounded copper mesh would stop virtually all electromagnetic radiation, whether proton or neutron. Obviously, they had to protect their monitoring equipment! Thus was born the "Faraday cage."

The copper mesh, like 1 inch chicken wire, worked well in large uses, like covering buildings, and it is still in use today: FEMA headquarters buildings are dome-shaped earth-bermed structures, and under the earth is a copper mesh that extends out from the base and is secured by grounding rods.

As an Electro Magnetic Pulse (EMP) travels to earth, whether from a Coronal Mass Ejection (CME) or a nuclear detonation in the atmosphere, it hits and runs along electrical power lines as well, building up voltage and amperage, which is what happened during the last solar storm a dozen years ago, blowing out transformers and leaving 6 million people in eastern Canada without power for weeks.


To prevent that problem, if you have a hard-wired generator, the wiring from the generator to the house should run in conduit that is grounded. The generator itself can have the frame grounded for added insurance, but that ground wire MUST be insulated and run to a different ground rod well away from the ground rod for building and conduit! See the article on EMP and various grounding techniques for electrical appliances, plus grounding metal sheds for generators.

"Electric fields travel in straight lines, unless bent by other fields. Theoretically, the bottom of a cage doesn’t need to be closed. If someone could offer me actual EMP test data that an open bottom is OK, I’d consider believing it. However, if you’re in an area of high ionization, the field could bend around. Complete enclosure is the best technical solution.

"Faraday cage material: Electric fields are best conducted by materials that conduct electric current the best – silver is #1 and copper is #2. Aluminum is ~60% of copper. Iron/steel is farther down the scale. Aluminum is a good poor man’s foil against EMP; double wrap it to be safe. I prefer copper foil." Ikstrums, Sept. 2, 2005

Here is the tiny GP-4L Survival Radio I sell at my Survival Shop and a Faraday Cage I built for it using a plastic box travelers use as a soap container. You can easily make a Faraday cage for this radio as I did.


With radio's and smaller appliances, a Faraday cage can be built by using two cardboard boxes: one should fit tightly inside the other, and the item to be covered should itself fit reasonably well inside the smaller box. That is about the most work involved--finding the right size boxes! The outer box is then covered with aluminum foil or Mylar, as from a cheap "space blanket." A grounding wire is then taped to the foil. I then cover the foil with black 6 mil plastic, taped securely in place, to protect the foil from ripping. At the end of the ground wire I attach a cheap small alligator clip from Radio Shack. The item to be protected is placed inside the inner box, which acts as insulation from the outer box, and any EMP hitting the foil and is bled away by the ground wire.


Some medium sized electrical equipment can also easily fit into boxes covered with foil for EMP protection. My laptop computer, for example, fits easily into a Faraday box made from a box that held reams of paper: the entire lid is removable, allowing easy access to the laptop in its case, but is safely stored when not in use.

For larger items which cannot be boxed, such as living room TV sets, etc, I tape a Mylar space blanket to a piece of 6 mil black plastic sheet, using double-sticky tape every foot or so to make sure the Mylar stays in place (it is slippery). I leave a 2 inch edge of black plastic showing all around the space blanket, and while taping down the edges I put on a short lead of ground wire. When it appears that EMP or CME's are on the way, the blanket can be draped over the appliance, the alligator clip attached to a small, unobtrusive ground wire behind the cabinet, and any electromagnetic radiation will be diverted to the ground wire. Very cheap, simple, and once done, items can be "draped" for protection very quickly indeed. The "EMP Blankets" roll up for storage, but can be unrolled and thrown over a TV/VCR setup, a computer/monitor combo, etc. As EMP comes from altitude and is line of sight, it's OK that the bottom isn't covered, as the bottom of the units sit on non conductive wood.


The time to build Faraday cages or blankets is NOW, as when they are actually needed it will be far too late. Each box should be labeled on the ends and the top for the exact appliance they were built for, to eliminate any confusion when they must be protected in a hurry. Any electrical appliances not in use should be stored in the Faraday cage, where they will be kept clean, neat, in a known location, and protected against any sudden EMP surge.

NOTE: There are electrical engineers who say that only ferrous metal boxes will protect against EMP-enhanced weapons, while other sources say EMP is not a problem at all. I'll take the middle ground.

Back, left corner of metal shed is grounded with 1/4" ground wire to a ground rod. The wooden floor of the shed is non conductive.


A nuclear ground burst over 200 miles away should only result in 50,000 volts per square centimeter (sc) on your equipment, so the above Faraday cages should work. An air burst within 200 miles can result in up to 100,000 volts per sc, and that would require grounding of any Faraday cage to a separate ground rod well away from any house ground rods. An enhanced EMP weapon exploded at 200 miles elevation can yield over 120,000 volts per sc within up to 600 miles below the detonation point, and that would definitely require insulated metal boxes which are grounded. Remember, in the battle of warhead versus armor, the warhead usually wins, as the warhead can be made bigger. However, for those who build simple Faraday cages and live in an area not likely to receive a direct or close nuclear attack, the foil cages described should work. Those under a direct or close nuclear attack would probably not survive to use their electronic equipment in any case.

For a more details examination on EMP and its effects, click at left.

So if you have a pacemaker do you need to build a Faraday cage for yourself?

Basically.

Bear,
I think you mean well but what you are proposing constitutes major fear mongering.
I believe that the times of nuclear explosions are in the past, to explode a nuclear device is a very complicated mathematical equation and they can’t be exploded randomly. That believe system was manufactured during the so called “Cold War”.
Brainwashing through fear mongering.
Sit back and enjoy your electronic equipment and should I be wrong go outside and enjoy the light show.

If our cities are attacked with nucks it would be suicide for tha attacker. Our responce would be devastating. However a few nucks detonated a couple of hundred miles up over the mainland will wipe out the grid. I don't give a rat's ass that you think the Zeta's or the Galactic Fed will stop it, you do not know! You best hope and pray calmer heads will prevail!

AH, good 'ol fashion failed GLP doom!!!!!

Dam I'm surprized to find this thread still being looked at I haven't posted as "Bear" in a long time.

Damn and to think back then I could edit nuck

If electrical systems are not plugged into a circuit, wouldn't they be exempt from the electroshock zapping event?