Protecting Electronics in Metal Military Surplus Ammunition Cans- Part 3, by J.T.

I am sharing a better solution for protecting sensitive electronics stored in metal military surplus ammunition cans made into a Faraday cage. In the Part 1, I talked about the ammunition cans that can be used and began the instructions for building ammunition can gaskets by listing the materials and tools required. Part 2 of this series consisted of the bulk of the instructions of how to make and assemble the RF and EMP shielding gasket, and we are continuing with these today, in Part 3. The following instructions are for a 20mm M548 ammunition can. 16. If you want …




Protecting Electronics in Metal Military Surplus Ammunition Cans- Part 2, by J.T.

I am sharing a better solution for protecting sensitive electronics stored in metal military surplus ammunition cans made into a Faraday cage. In the Part 1, I talked about the ammunition cans that can be used. We then began the instructions for building ammunition can gaskets by listing the materials and tools required. Now, let’s move on. Making and Assembling the RF and EMP Shielding Gasket The following instructions are for a 20mm M548 ammunition can, which is my preferred can size. If using another ammunition can, you will need to make adjustments in measurements within these directions to adjust …




Protecting Electronics in Metal Military Surplus Ammunition Cans- Part 1, by J.T.

In this multi-part article, I am sharing a better solution for protecting sensitive electronics stored in metal military surplus ammunition cans. There are many references for making a Faraday Cage on SurvivalBlog. Some references go back as far as 2005. One solution was proposed in 2006 that required the removal of the rubber gasket on ammo cans and replacing the seals with a conductive material (stainless steel or steel wool). Other articles suggested the use of a galvanized garbage can that is sealed up with conductive metallic tape, or an open head steel drum, or using an old microwave oven …




Letter Re: Does EMP Affect Solar Panel Systems?

EMP Solar Panel Good day sir. The talk of EMP has greatly increased recently for many reasons you are well aware of. What would happen to either grid tied or non grid tied solar systems in this instance? What would happen to generators as well? – R.C. HJL’s Comment: Two of our Writing Contest sponsors, Portable Solar LLC and Quantum Harvest, LLC, both specialize in EMP hardened systems. You should check their sites out and also the videos that they have on YouTube. We have several other advertisers that sell Solar equipment and it would be worth your time to …




Letter Re: EMP Protection Measures

Hugh and James: I’m missing something regarding EMP protection measures, and I could use some help. I have researched EMP, how it’s created, and the common frequencies of EMP. I’ve looked into its relative intensity based on creation mode, altitude (in the case of nuclear devices), and the extended effects attributed to conductive networks. I understand what a Faraday cage is and how it works. And I’ve read numerous articles, lots of forum comments, endless opinions, a quantity of engineering documents, and several much learned evaluations on protecting against EMP. The Problem So here’s where I keep running aground: Protecting …




Letter: Faraday Cage Question

Good afternoon!

I have a question on adapting a homemade Faraday cage. I am getting a little paranoid about these two North Korean satellites in orbit over our country.

Would a metal mailbox, such as can find at the local hardware store, be acceptable protection? I am trying to put together something simple for really, really cheap! It has a larger size and is easier to obtain. It is also cheaper than some of the other options I have been reading about on constructing a Faraday cage.  T.B.

HJL’s Comment:

Most any metal container will work as a Faraday cage with a few simple preparations. The metal needs to have a good electrical connection between the various parts. If you are using painted metal, you will have to remove the paint where the electrical connection needs to exist. Galvanized metal works really well. If a metal mail box is not large enough, you can consider a 30 gal trash can with a metal lid….




Letter: Advice for Disabled Suburban Retiree Preppers

HJL and JWR, I’m seeking links or tips on how a 77-year-old disabled person can defend his property in case there’s TEOTWAWKI. My wife is 72. We live in a middle class subdivision 45 miles from Cleveland, Ohio. Because of physical disabilities (neuropathy, bad knees and legs) I am not very mobile. I use walker/cane most of the time. We are moderately prepared (food, guns, ammo, junk silver, etc. A retired Marine lives at the other end of the block but says he will bug out if SHTF. Nobody else on the block seems even to be aware of the …




Letter: Using Military Ammo Cans for Faraday Shielding

Dear JWR: The use of military surplus ammo boxes as Faraday shields was recently mentioned again in SurvivalBlog.  But readers should be reminded that these cans will not work in the configuration where they are normally purchased.  This is because the boxes have a rubber gasket to seal the lid from water and that makes the lid not in [electrical] contact with the body of the can, thereby losing the [EMP] shield effect.  Regards, – Dave X. JWR Replies:  You are correct.  As mentioned previously in SurvivalBlog, the best approach is to remove the rubber gasket,  rough up the metal …




Letter Re: EMP Telltale

Hugh, Whenever the power goes out wherever I am, the first thing I do is see if my battery-operated watch is still working. I suspect one of these times, the screen will be blank or just chaos. – Sid, too near Niagara Falls HJL Comments: As technology advances, the gate sizes grow smaller making such electronics more susceptible, but at the same time manufacturers recognize that they are more susceptible to static electricity as well. As a result, manufacturers almost always include some basic protection in the on-board circuits. Add to that the concept that the amount of energy absorbed …




Letter Re: Using EMP-Hardened HF Ham Radio

Hugh, I strongly recommend against using any Heathkit rig for an emergency radio. There was one solid state Heathkit but it was a rebadged, factory assembled Yaesu. All others were built by an individual, whose attention to detail you most likely have no idea about. They are known in the hobby as “GRIEF kits” for a GOOD reason. They fail – early, and often. They have too many disadvantages for the emergency backup purpose. Besides all the ones mentioned by the original author: They have high (LETHAL) voltages inside. They require 120V AC power. They have no cooling fan on …




Using EMP-Hardened HF Ham Radio to Send/Receive E-Mail During Nationwide Outage- Part 1, by PrepperDoc

There are multiple possible scenarios that may result in a regional an/or national combined loss of Internet connectivity and cell/telephone service, during which you would probably wish to maintain communications to loved ones and others. EMP may destroy routers, cell towers, and power sources; solar coronal mass ejection (CME) may remove power from all communications systems; cyber warfare may have similar outcomes. Travel in some of these circumstances will be difficult, or dangerous to impossible. Ham radio VHF/UHF repeaters may go down, due to power outages or EMP. Direct, point to point simplex VHF Ham radio will still work (even …




Letter Re: Shielding Electronics From EMP

HJL, Another point on electromagnetic pulse (EMP) and Faraday cages is even something simple can be protective. There are 30 Gallon galvanized steel trash cans with lids (made in the USA!) available at my local farm and ranch store for $22. This makes for affordable and easy storage, and you can wrap things in common aluminum foil. Or even something like a steel cabinet or vault, but generally try to avoid gaps or spaces. It doesn’t have to be zero signal, but reduce the field strength enough to prevent damage. Vehicles have some protection for many years. In the early …




Two Letters Re: EMP Effect and Pacemakers

James: While case-by-case circumstances can effect the practicality of many alternatives, there are external pacing and monitoring options. The Zoll Company for example has just released a type of vest, worn similar to a brassiere with a fanny pack (battery pack). This device consistently performs cardiac monitoring and when a shockable rhythm presents itself the device does just that. More archaic methods would involve adhesive defibrillation or subcutaneous pacing patches and a cardiac monitor, while the monitors can be significantly expensive, older models are available at online auction sites. Both the aforementioned devices can be recharged, and more importantly, stored …




Letter: EMP Effect and Pacemakers

Hugh, I have an implanted cardiac device (a pacemaker and defibrillator) and, after reading the letter about possible effects of electromagnetic pulse (EMP) on batteries, became curious as to how an EMP or maybe a strong solar flare could affect my device. I searched SurvivalBlog’s archives and saw that such an event could possibly damage the implanted cardiadefibrillator (ICD). Is there any firm evidence as to what may actually happen to an ICD or similar device in the human body and anything that can be done to counter the effects? It seems it will be a bleak future for the …




Letter Re: EMP Question

Hugh, I’ve asked Matt Bracken this question, and he didn’t know. I’ve read all of your EMP-related data, but none of them answer the question of whether batteries, particularly the small D, C, AAA, AA types need to be shielded to protect them from EMP. All authors make much of electronics in devices but never mention separate stores of batteries or the dangers of batteries stored in electronic devices like radios, sights, et cetera. Your advice would be greatly appreciated. – S.D. Hugh Responds: There is much FUD in the online world (and in books) about EMP. Some of it …