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. …