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Electromagnetic Pulse


(Photograph courtesy of Miles Stair, http://www.endtimesreport.com )



Miles Stair's Survival Shop

The reality of protecting all electronic equipment against EMP from a nuclear explosion over our shores is becoming imminent. We now live in perilous times.

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 square centimeter on the ground. 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!

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. And the plastic blankets fold up neatly for storage, ready for use when needed.

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.


EMP (Electromagnetic Pulse) info. collection
This page will remain in a constant state of expansion, so bookmark and revisit often!
Last updated: June 28, 2003 -
Added "Hardening Your Computer Assets" and the link to the
Journal of Electronic Defense.


General EMP Info.
QST Magazine Articles
Military Manuals
Equipment Manufacturers
Faraday Cages
Congressional Testimony

"...the de facto national policy of nakedness to all of our potentially EMP-armed enemies takes on ever more the character of national scale masochism. It is perverse, irrational, and assuredly not necessary or foreordained."
- Dr. Lowell Wood, Lawrence Livermore Labs

What is EMP?
According to the Institute for Telecommunications Sciences, Electromagnetic Pulse is:

"1. The electromagnetic radiation from a nuclear explosion caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the nuclear 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. May also be caused by non-nuclear means;

2. A broadband, high-intensity, short-duration burst of electromagnetic energy. Note: In the case of a nuclear detonation, 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."

In plain language, it is an electromagnetic "shock wave" that is released from nuclear detonations that can seriously damage any electrical components in its path. EMP can travel either through air or through conductive pathways such as electrical or phone lines. It can affect electronic equipment regardless of whether the equipment is switched on or off.

The goal of this site is to help you protect your communications and computing gear from EMP, as well as provide an understanding of the threats to and vulnerabilities of our electronics-based society.

General EMP Information
The Electromagnetic Bomb - A Weapon of Electrical Mass Destruction - a long and interesting article on E-Bombs.
Balanced Electromagnetic Hardening Program - R&D wing of the Defense Threat Reduction Agency.
Electromagnetic Pulse-From Chaos To A Manageable Solution - A very interesting white paper by a USMC Major on the EMP threat, dated 1988.
A short Popular Mechanics article from 2001 on E-Bombs and the potential for terrorists to use them.
The Threat of High Altitude EMP to Force XXII - 20 page 1997 article from National Security Studies Quarterly on the threat to US Forces from EMP - Adobe .pdf document.
Hardening Your Computer Assets - an article by Carlo Kopp on how to protect IT systems from EMP - very good! Adobe .pdf document.
QST Magazine Articles - 1986
In 1986, QST magazine published a 4-part article on "Electromagnetic Pulse and the Radio Amateur". The article offered some in-depth technical information on hardening radio equipment against lightning strikes or nuclear explosions. More than you ever wanted to know...
Here are the 4 articles in Adobe Acrobat: (NOTE: files are hosted at the ARRL.org site)
Article 1 - How EMP works and its effects on antennas, equipment, phone lines, etc. (1.09MB .pdf file)
Article 2 - Tests of EMP & transient protection devices. (523k .pdf file)
Article 3 - More tests of EMP & transient protection devices (583k .pdf file)
Article 4 - Procedures and products to protect your gear (568k .pdf file)
Military Manuals
Military Handbook MIL-HDBK-1195 30 (SEPTEMBER 1988) - "Radio Frequency Shielded Enclosures" - 79 pages of technical and practical informtion on shielding devices from EMP and EMI. HTML Version or the Zipped Version which includes all the illustrations.
Field Manual 24-18 (Tactical Single Channel Radio Communications) has some good EMP info in Appendix J.
US Army Corps of Engineers Pamphlet EP 1110-3-2 - "Electromagnetic Pulse (EMP) and Tempest Protection for Facilities"; a 467 page technical manual!
EMI/EMP Shielding Equipment Manufacturers
Manufacturers' websites, ranging from bomb-proof to simple surge protection.
CCI - Conduit-mount and explosion-proof EMI suppressors
Chomerics - EMI/EMP shielding for cables that uses a sheath that you zip around the cable and connections
Citel - Coaxial surge protectors, AC surge protectors, and more - good stuff!
Control Concepts - mostly large industrial applications
Fischer Custom Communications - check out the EM Pro Cord...neat stuff.
NexTek - mostly lightning surge protection, but still good stuff.
Polyphaser - Great products for the protection of your commo gear!
Faraday Cage Information - Faraday cages are devices that protect objects within the cage from electric charges and EMP. Based upon principles put forth by Michael Faraday in 1836, the Faraday cage is still being tinkered with by modern inventors. There are a LOT of strange ideas out there on what Faraday cages can and cannot do. I've tried to filter out the wingnuts and provide only solid data:
Bolt Lighning Protection - An EXCELLENT overview of the basic properties of a Faraday cage.
Dixel Electronics - This Israeli company manufactures all sorts of fascinating products like Mu-copper foil that you can roll onto walls like wall paper to create your own EMP-safe rooms; transparent protective mesh you can add to windows and more...
Congressional Testimony on EMP Topics
1997 Congressional Testimony on the effect of EMP Blasts on the national infrastructure in the House Committess on National Security - a long and fascinating read; Note - sometimes this link works, sometimes not - keep trying.
1999 Congressional Testimony on the effect of an EMP attack on the US economy.
1999 Testimony in front of the House Armed Services Committee from Dr. Lowell Wood from Livermore National Labs on the EMP threat.
1998 Testimony in front of the Joint Economic Committee on "Radio Frequency Weapons and Proliferation"
The Journal of Electronic Defense - Publication of the Association of Old Crows, an association of electronic warfare parctitioners - very professional!