Category: EMP

Protecting Both Tube and Transistor HF Communications Equipment From E1 EMP Pulse- Part 2, by PrepperDoc

Transistor / QRP Equipment The solutions shown so far may not adequately protect computer-based software-defined radios, hybrid transistorized-vacuum tube radios, or fully solid-state QRP or low-power stations, or transistorized shortwave radios. These radios will need to use protection that clamps at a much lower voltage than 700 volts! While transistor transmitters may use power amplifier transistors that may have breakdown voltages in the scores to hundreds of volts, the input circuitry of many QRP transistorized receivers will likely be fried with voltages well under 100 volts. There are a couple of solutions that can offer lower-voltage clamping more appropriate to …


Protecting Both Tube and Transistor HF Communications Equipment From E1 EMP Pulse – Part 1, by PrepperDoc

Introduction and Tube Radios Electromagnetic Pulse (EMP) is a serious national threat with growing public awareness. A high-altitude atomic/nuclear explosion sends electrons plowing through the earth’s magnetic field lines and thus generates powerful radio waves that impact the earth below the explosion within a radius of many hundreds to thousands of miles. The peak field strength is immense, on the order of 50 kilovolts per meter, and covers a very broad frequency spectrum, from very low frequencies, past 100 MHz; but the first wave (named E1) is evanescent, over in a mere microsecond or so. There are additional, slower incident …


Letter Re: Question on generators and EMP

HJL, We have been considering having a whole house generator installed at our house, since we occasionally lose power in our neighborhood for days at a time. Additionally, the threat of an EMP pulse damaging the grid and our being without power for a lengthy period of time is an even greater concern. My question is: is a whole house natural gas powered generator, like a Generac 22kv unit (along with the associated auto switching panel), susceptible to EMP? If so, what would be the best way to protect it? When I ask the electrical contractors bidding on the job, …


Letter Re: EMP-Hardened Ham Radio Communications, by PrepperDoc

Being a prepper and a Ham I found the article “EMP-Hardened Ham Radio Communications” by PrepperDoc very interesting but also somewhat over my head with regard to tubes and the like, so I put it out to more experienced members of our ARC (amateur radio club) for comment. The response from one Ham is not a slam but rather additional information for the like-minded. “There was no mention of electrolytic caps and the frequent need to replace them when using older gear. Also, tube rigs are power hogs; where are you going to get the power? Alternate power sources (inverter …


EMP-Hardened Ham Radio Communications, by PrepperDoc

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EMP attack is often considered the most rigorous of survivalist situations, due to the likely complete loss of electrical grid, many vehicles, and many transistorized/computerized products. Our group worked to provide post-EMP communications that would allow effective communications post-event. We had two major requirements: Short Range Communications. Two, separate, defense-hardened homes that were approximately 30 miles apart had to be able to communicate across a medium-sized city, and Long Range Communications. Both homes had to be able to receive news from in-state and out-of-state sources. These were considered necessary to receive adequate advance warning of defense issues, such as advancing …


What Can We Expect and Do Now To Prevent a Nuclear Power Plant Meltdown in an EMP Scenario, by B.Z.

I was prompted to write in response to the reader who commented on the recent article entitled “Six Common Misconceptions About EMP”, by G.P., which was published in December 2014. The reader asked specifically: “Can we expect the 100+ nuclear power plants in the country to have meltdowns when the grid can no longer supply the power these plants need? In particular, what about the spent fuel pools?” Let me first say that I personally have met the author of this article, and I can attest that he is one of the foremost experts on EMP in the world. My …


Scot’s Product Review: MobileSec Cellphone Blocker and Laptop EMP Shielding

I always liked the line that states, “Just because you’re paranoid, doesn’t mean that someone isn’t out to get you.” These days, in addition to physically trying to “get” you, there are also those who are trying to virtually get you by stealing your information for misuse. There are those who might want to wipe out everything with an EMP event so that not only do you not get to use your own stuff, you can’t even get a backup from someone else. It could be a foreign government, a criminal consortium, or even your own government doing the deed. …


Letter Re: Six Common Misconceptions About EMP

A question for the writer of the EMP article. Though the article was informative, he, like pretty much everyone else that writes about EMP’s or other forms of grid failure, completely ignores the 900 # gorilla in the room. Can we expect the 100+ nuclear power plants in the country to have meltdowns when the grid can no longer supply the power these plants need? In particular, what about the spent fuel pools? My understanding is that they have emergency generators and anywhere from a few days to a few weeks worth of fuel on hand but even if somehow …


Guest Article: Six Common Misconceptions About EMP, by G.B., PhD

Many misconceptions about electromagnetic pulse (EMP) effects have circulated for years among technical and policy experts, in press reports, on preparedness websites, and even in technical journals. Because many aspects of EMP-generation physics and its effects are obscure, misconceptions from those who do not perceive the seriousness of the effects to those who predict a doomsday chain of events are inevitable. However, not all EMPs are the same, with the most significant effects being caused by E1 and E3 fields. Nuclear bursts detonated at altitudes above 40 km generate two principle types of EMPs that can debilitate critical infrastructure systems …


Letter Re: EMP

I currently keep my backup mini-iPad in an EMP bag. Do I also need to keep my power supply for it there, too? Thanks – A.B. HJL replies: Yes. In fact, it is probably more important that the charger is in the bag than the ipad. Being an electrical engineer with considerable radio technology experience, I have a perspective that is a bit different than most on the subject. The true danger of EMP is in having antennas or things that act like antennas pick up the electrical energy. If the object in question either has wires or parts that …


Letter Re: EMP

Hugh, While the routers and switches do require power (which will be spotty at best), they too will be fried by the EMP. Many of the modern ASICs are based on IBM proprietary copper chips and as a result really don’t get along well with any form of EMP. It’s bad enough that I’ve seen a floating ground stretched between two buildings fry Cisco, ACC / Wellfleet, and Extreme gear. The only purpose-built router that is tempest hardened is the very old TGS router by Cisco. This was an AGS that was built into a hardened shell. Wide scale deployment …


Letter Re: EMP

Hi Jim, Do you know if we have a EMP attack or if the grid goes down weather we will still have internet service? – GLB HJL Replies: Since the vast majority of the Internet depends upon the power grid, it really depends on how much of the power grid survives an EMP event. The long hauls of the infrastructure would probably survive due to the fact that most are based on fiber optics, which are not affected by EMP. The hubs, connection points and routers all have to have power though, which is affected by EMP events. If the …


Guest Article: EMP Myths and FAQs, by Joel Ho

Q: Do Faraday Cages need grounding? A: No. A Faraday cage designed against EMP, if properly constructed, will keep any charge outside the shield. The shield interior is separate, so anything inside, even though it touches the inside of the shield, is safe. However – if the cage is improperly made and there are wide holes in the mesh exceeding the size of wavelength to be blocked, grounding could help. As an example, this Youtube video link is of EMP testing my company has done with another firm’s professional EMP simulator. You can see a shielded laptop on the left …


Letter Re: Preparing for EMP and DEW — A Layman’s Guide

Dear Editor: In answer to Norm’s question: Yes, insulating items that are already inside a Faraday shield appears to be superfluous. As long as the shield works (is unbroken and made of the right materials and configurations to counter the frequencies targeted), the overwhelming vast majority of the energy does stay outside. This has been verified in our tests and is a basis for the products we make. For example, we tested our laptop EMP shield against an EMP simulator made by APELC in Texas – no visible upset was observed despite their machine throwing over 150 kV/m at our …


Preparing for EMP and DEW — A Layman’s Guide, by Joel Ho

As and engineer and founder of an EMP protection startup company , I wanted to explain some EMP basics and also educate readers about current Directed Energy Weapons (DEW.) Qualifications: My team has developed the first EMP simulator-tested laptop EMP shield that lets you protect and use your laptop (including wireless.) So, over the past year, we’ve learned firsthand what’s true and what’s not regarding radio frequencies. All subjects mentioned are the opinion of MobileSec Solutions LLC but not legally binding.   General Overview Electromagnetic pulse (EMP) is generated usually when a nuclear device is detonated in the upper atmosphere. …