communication equipment after EMP....... faraday cages

[knuckle Head]

You may consider lining the inside of the metal trash can a rubber tool box pad like this one Solid Nonslip Drawer Liner put in, cut to fit get good glue and glue in the pad, take a metal rod put it in the ground a couple of feet and run a copper wire from the garbage can to the grounding rod.

Here are some interesting materials to read

<broken link removed>

http://www.hsdl.org/?view&did=695348

Oh BTW, if the terrorist want to detonate an emp over the senter of the U.S., I see it like this

First they will do it when a natural disaster or during riots in our streets. Remember what is going on, people are being made dependant on entitlements once the milk runs dry those made dependant will be rioting demanding more, lots of civil unrest coming next few years.

Second, they have all the funding they want from their true primary backers in S a u d i where the true radical muslims are from

Thrid, I recenty put my portable midland and motorola in rubber gloves then into mylar bags with O2 absorbers I made, put it all in th absement in a metal can and grounded the can to the water pipes. Got all my ideas from the tremendous response on here.

 

[branchbuster]

Good point about the gun safe, it just needs to be grounded. With an EMP, a ungrounded metal container may make things worse. But at least it will hold the smoke in.

 

[Siglvr]

Good point about the gun safe, it just needs to be grounded. With an EMP, a ungrounded metal container may make things worse. But at least it will hold the smoke in.

<broken link removed>

Ground or not ground the Faraday Cage? I'm thinking not. From the link above, if the explosion is a traditional air or ground burst and not rigged to emphasis a large EMP, it looks like you really only will be nailed by an EMP if you are right inside the blast zone, in which case, you will have other things to occupy your mind. ie, radiation burns, exposure, etc etc. Get inside and hunker down. Having electronics will be the least of your concerns for quite sometime. In this very instance it appears that there is a much higher likelihood of the pulse tracing your ground back to your trashcan/gunsafe stash and then knocks it out via direct conduction. So you'd be better off in a nuclear explosion non-grounded.

"Another EMP phenomenon called source-region EMP may lead to conductance of electricity through conducting materials (e.g., pipes and wires) and could cause damage much farther away, but this subject requires further research and analysis. Because the extent of the EMP effect is expected to occur relatively close to ground zero..."

Blast Damage Zones
There will be minimal, if any, ability to send or receive information in the blast damage zones (LD, MD and SD zones). It may be days before communications capabilities are reestablished. Within this area, all communications capabilities will be destroyed or severely hindered. The blast will cause physical damage to communications systems &#8211; electrical, phone and cellular systems will be down. The EMP will devastate electronics. Televisions, computers, cell phones, and personal digital assistants (PDAs), such as BlackBerry devices, may all be impacted. Cell phones or PDAs that do withstand the EMP impact will likely be in
1 Homeland Security Institute 2009
118
the hands of survivors, because the person possessing it is sufficiently confined in a substantial underground location such as a basement, underground parking garage, or subway system. The sufficiency of the shelter could render the cell phone or PDA useless until a survivor finds a way to the surface. However, if the person were to do so, they could subject themselves to life-threatening radiation exposure.
Communicating after a nuclear detonation will be difficult. The blast and electromagnetic pulse will damage communications infrastructure and devices for the population in the blast damage zones and potentially cause cascading effects in the surrounding areas, including the most critical region for communications &#8211; the dangerous fallout (DF) zone.

The EMP should have limited, if any, effect on electronic devices in the surrounding area and DF zone outside of the blast damage zone. Electronic devices may only require resetting switches and circuit breakers.

 

[erudne]

I remove the batteries from my electronics and wrap them all in rubber from innertubes, place the package in an ammo can, wrap that in an innertube put it all in a plastic trash bag, put that in a metal trash can, ground the trash can inside a metal shed.
I ground my vechicles using a metal rod and jumper cables to clean spot on the bumper, parked under a metal roof carport.

 

[CarlMc]

I got involved in a number of threads on the topic over at the Survivalist Boards, where more folks know way too little, or just enough to be dangerous. There's way more very wrong things on the web than there are right things. I got tired of trying to explain the same thing over and over, so I started a thread on the topic. I'm far from an expert in the topic, but it was obvious I knew way more than the average layperson. I took several hours and put together a rather deep dissertation on the topic.

Faraday cages and EMP, a deep dive - Survivalist Forum

Before you sit down with this, make sure you're well rested, had breakfast, and have a pot of coffee or a six pack of Mountain Dew. It took twice that much for me to put together!

 

[erudne]

I'm redundent. I'm redundent all the way down to anvils, forges, shovels, hammers even horses. My EMP preps are 3rd tier because I don't need battery powered comms. I use civil war comms, lights and flags.
If my radios are the only ones working localy then the bad guys will home in on that signal, because thier comms were handed out AFTER the EMP

 

[Cedar]

use civil war comms, lights and flags.

Batteries in a jar in straw with a telegraph? I saw that 2 years ago at Mission. Pretty sweet setup that worked.

Cedar

 

[Cedar]

Are you guys making a faraday cage more difficult than it needs to be, or am I simplifying it too much?

I picked up a Tom Mann Bird Trap Depthfinder case for $1 which fits all my radios and chargers in it. It is a 1970's steel box which is lined with foam to cushion the depth finder. Fits my stuff perfectly. I could tape around the seal where the lid shuts on it with metal ducting tape if I want, but it seems to be a tight fit.

Cedar

 

[CarlMc]

In short, just about every homemade Faraday cage will not protect your equipment from a real EMP. Just because your cell phone doesn't work in some kind of metallic looking box doesn't mean a stinkin' thing as to its performance in an EMP situation. I hate to burst folks' bubbles, but if you insist on believing folks who have no knowledge of intense electric and electromagnetic fields, you should just put on your bleepin' seatbelt, because your seatbelt will protect you from known, common, and understandable threats, unlike some silly piece of sheet metal saving your treasures from EMP, which is extremely rare to the nth degree, poorly understood even by the top scientists, and extremely difficult to protect against.

If those who insist on protecting themselves against EMP, you can either swallow the placebo of screen cages or get serious, go do the work, and get smart. If you can follow the discussion linked on post #25, then you can likely make some real progress. I'm not claiming I know it all, but this is some deep stuff, and you need some understanding of electricity beyond high school to have any chance to accomplish what you want.

 

[Cedar]

I actually got the metal box as I am rather hard on equipment, it gets moved alot, tossed around in the truck, the price was right and was hoping maybe it would double as a faraday cage. A faraday was not high on my priority list, but the opportunity came up so I took it.

Cedar

 

[DEADTIME]

Get a cheap metal trash can wrap it in chicken wire, cheap and effective.

 

[CarlMc]

Get a cheap metal trash can wrap it in chicken wire, cheap and effective.

This isn't personal when I ask this, so don't take it wrong. Can you show me where a trashcan has been shown to be effective against EMP? I keep hearing that, but I don't believe that the can by itself (with or without chicken wire) can be effective against EMP. I play in the high energy field where I work, and have a better understanding than most folks, so when I ask the question it's strictly from a scientific viewpoint.

 

[salmonriverjohn]

This isn't personal when I ask this, so don't take it wrong. Can you show me where a trashcan has been shown to be effective against EMP? I keep hearing that, but I don't believe that the can by itself (with or without chicken wire) can be effective against EMP. I play in the high energy field where I work, and have a better understanding than most folks, so when I ask the question it's strictly from a scientific viewpoint.

CarlMc, Having read post 25, I do appreciate the effort to enlighten the layman, that was an exhaustive effort to say the least, and I thank you. Perhaps now instead of pointing the many ways that it can't be done, possibly you could teach the way that it can be accomplished. Lead the way!

 

[CarlMc]

CarlMc, Having read post 25, I do appreciate the effort to enlighten the layman, that was an exhaustive effort to say the least, and I thank you. Perhaps now instead of pointing the many ways that it can't be done, possibly you could teach the way that it can be accomplished. Lead the way!

That requires a funding source you don't have...
Nonetheless, I do think the trashcan idea has merit, but there are a number of weaknesses. One, the steel is thin, and the magnetic permeability of steel (and cheap steel at that) means a strong magnetic field will saturate the sheet metal in no time, allowing the oversaturation field to pass right on through. Secondly, the can has loops on it--the handles, and any metallic loop of any kind is a very bad thing in any emp environment. However, you can cut the handles off. In that thread we discuss the various containers that have merit, such as ammo cans, trashcans, gun safes, file cabinets, ammo cans, and such. Each of them has strong points and weak points.

If it were up to me, and I felt so strongly about that problem, I'd take a thick walled steel pipe with threaded end caps (sounds easy until you find out how expensive that really is) and place inside it a thick walled copper pipe (also incredibly expensive) with soldered on end caps, separated by at least a quarter inch of gap at all spots. Ensure that all corners are rounded off as much as possible. That gap can be plastic, cardboard, or whatever suits you. Coat the steel pipe in bedliner or other very sticky and leak proof material like tar or asphalt. I don't worry about the grounding, because I'm going to bury it in the ground in a hole dug with a post hole digger or auger. I'm going to put it in about six feet deep, and cover it with tightly packed soil. If my soil is low in mineral content, I'll add salt to the soil and keep it at least slightly damp. Getting it out will be difficult, obviously, and you don't want a metallic pull cord to find it. The salt, moisture, and mineral content will want to corrode the container, which is what the coating is for. This contraption should be no larger than absolutely necessary. The bigger it is, the deeper you should go and the thicker the walls need to be. There are those plastic tubes for survival gear that could encase the whole thing, but you really want the soil to be as close as possible to the outer metal tube. Ideally, it would make contact, but the corrosion problem outweighs the benefits of an electrical connection (and it's the electrical problem that causes it to corrode even faster.)

Now I get to explain why: The first layer of protection is the soil itself. The ground presents a huge ground plane, which greatly attenuates the electric field component of the EMP pulse. The more you disturb the soil, the less it can do its job, so I bury it in a vertical hole. The vertical orientation reduces the cross sectional area of the container presented to the follow on magnetic field. If the lines cut across the broad side of the tube, then effects will be created inside the container, which we can reduce dramatically by mere vertical orientation. The second layer is the tube. Providing the cap is tightly threaded on and no lubricants or other contaminants such as rust is present in that threaded joint, you can consider it a contiguous joint, and not become an antenna in itself or an isolated conductor. The thicker the wall the more the steel can reroute the magnetic field that will be present in the earth, and what does make it through, will be converted into eddy currents in the copper tube. What makes it through the copper tube will be heavily attenuated (reduced in strength) that not much of a hazard should be left. There will likely be some voltage potential between the tubes as well as to the soil, but since no insulator is a perfect insulator, those charges will bleed off through the insulator in the time it takes for you to locate and extract your treasures.

Now this solution has holes in it big enough to drive a truck through, but I think it's still better than any other proposal I've seen. The practical problems are that you will have a dickens of a time getting it out of the ground, it's small and hard to open, and you're going to have a very tough time deciding what to put in it. From a big picture perspective, can you guarantee you will always be where you can gain access to your precious treasures?

Using a microwave oven case is about one of the most useless ideas on the planet. The microwave body is designed to keep ONE frequency from getting out, not an extremely broad range of frequencies from getting in. When I first read about that concept I had to smack my head, but since folks don't know what they don't know, and my definition of stupidity is the refusal to correct their own ignorance, I moved on with my life.
Cell phones, GPS units, and any of those silly little electronic devices upon which we have surrendered our lives to will be useless, all because the supporting infrastructure will be damaged too heavily to support them. If they don't need support infrastructure (and you can keep the batteries happy) then the odds of them being useful are better. The smaller the electronic device the more likely it will survive. I know this sounds counterintuitive, but smaller devices create less internal eddy currents and pick up less EMF from external sources than those with larger conductors and components. Near the end of the thread mentioned, there's a video of magnetic fields from a simulated lightning strike (not EMP, which is thousands of times more powerful, as well as very much different in effect) blowing apart power transmission lines.

That'll be two hundred bucks from each of you that read this article, please. Cash only.

 

[salmonriverjohn]

A funding source that I don't have is a very assumptive statement! I like the pipe Idea, very do-able Carl. I appreciate your input on this subject. You seem to have a good grasp on advanced electrical theory and principle. Good input is invaluable. I like the edit post also, it's always possible to miss something, like the fact that you asked for cash, and damn if I didn't send a check in the mail

 

[IronMonster]

I learned more than I expected just with the bit of information here. I have seen several actual examples of Faraday cages in use for high voltage demonstrations... I was lucky enough to see first hand a guy in a chain mail suit standing under a 20 foot tall Tesla coil and the voltage passing over his body and leaving his feet.... The only thing I want to contribute and while it probably is obvious to those with more of a understanding (I am one that only knows enough to be a danger) Is that the discussion really should not be about what constitutes a Faraday cage but rather what type of Faraday cage has a hope of stopping the wavelength of a natural or man made EMP... A trashcan is a Faraday cage but as pointed out is not likely sufficient protection for any real world situation where protection is required from a magnetic pulse radiation source. I keep my electronics in a fire cabinet used to store paint and flammables.. I keep them wrapped in cardboard inside the cabinet.... Will this protect them from a EMP burst over Seattle or a Gigga solar flare? Hell I dont know but I figure its got to be better than them in the kitchen cupboard. We tend to loose sight that the goal is to do the best job we can, Nothing you do in any prep will guarantee it will be there and work when you need it. Its your responsibility to try to reasonably guard against the most likely problems and if possible redundancy. If its critical to your survival then take the steps talked about above.... The whole steel/copper buried pipe thing makes perfect sense to me and if you have gear and need of that gear that justify the effort and expense then you probably have the motivation to make it happen.... I think that most of us, Me at least has a little peace of mind that I have minimal protection and that if there was a EMP burst over Kansas that maybe my short wave radio and CB would still work... Maybe it wouldnt... But Its not important enough to spend a weeks work and a $1000 to protect my $100 radio...

 

[IronMonster]

And Thanks Carl.... I can see a lot of work went into your reply's and original post on the other forum. Before reading this I thought my stuff in my metal box was at least some sort of protection but after reading your info I have my doubts.. I have the ability to build something that would offer some protection but the effort seems silly given the cost and effort and what I have to protect. On so many levels we think we have an understanding based on misinformation. Anyway Just wanted to say I for one appreciate the effort even if it does wreck my feeling of security...

 

[CarlMc]

And Thanks Carl.... Anyway Just wanted to say I for one appreciate the effort even if it does wreck my feeling of security...

I appreciate that. I really do. I have my own definition of ignorance and stupidity. Ignorance is merely not knowing, and quite often we don't know what we don't know. Stupidity is refusing the opportunity to do something about it. Many folks get all worked up when their premises are challenged, and I've learned to my own discomfort that I'm far from knowing everything as well. A better man is willing to consider his own ignorance.

Discussions about EMP constantly remind me of George Contor's Law of Conservation of Ignorance:
"A false conclusion once arrived at and widely accepted is not easily dislodged, and the less it is understood, the more tenaciously it is held."

The point when I ask constantly "Do you wear your seatbelt?" is to make the most predictable and repeatable threats your top priority.
As far as my own personal preps for EMP: nothing. Civilization lived for hundreds of thousands of years without electricity; I'm sure we can do it again if we have to. The human being is incredibly capable. It took hundreds of years for electricity to get where it is now; just imagine what the learned mind can do to recover. The EMP threat is so unpredictable that it's like trying to prepare for that lion that will escape from the zoo fifty miles away, get inside my house, curl up on the couch with the remote and refuse to leave until his favorite episode of "Mork and Mindy" is over. The odds are about the same. I don't play the lottery either, and you know those odds!

 

[oregonty]

Virtually evey home already has a Faraday cage; a microwave oven. They are designed to keep microwaves in so they will also keep them out. I have tested the theory by putting my cell phone in the microwave, shutting the door, and then calling it using my landline. It didnt ring because once the door was shut it didnt get a beam. You can get non-functioning microwave ovens for free at any metal recycling location, or at the dump.

I have to call BS on this. I just tried it and my phone worked just fine. I have two microwaves and it still worked in both!

 

[CarlMc]

There's a spot in my daughters' room where no cell phone signal exists. Don't know why, and cordless phones don't work either. If all that's required for a container to be EMP resistant is the ability to block cell and cordless phone signals, then my daughters' room is a great faraday cage, and I don't even have to spend any money fabricating one!

Those who think I'm not joking need to revisit your premises. There's a block of wood in my driveway that I use to keep me from backing my car into another car. If that block of wood can stop my little car, it must be able to stop a fully loaded train doing a thousand miles an hour, right?