http://www.endtimesreport.com/faraday_cages.html
Has anyone built any, is it a waste of time, any ideas either good or bad?

Here's a good series of articles from ARRL about EMP:

http://www.arrl.org/tis/info/pdf/88615.pdf

JimJr

I've built two. For what I needed, they were definitely not a waste of time. The most important thing is to establish as near perfect a ground as is practical.

Sorry to say, but even a (practical) Faraday screen is probably not going to do you any good with a strong EMP, say from a fusion explosion in the upper atmosphere. I wouldn't worry too much about a stray CME getting to your goodies. If we get hit with solar activity that strong, it'll knock out most all of our satellite circuits anyways.

I definitely don't go along with most of the applications the author of endtimesreport espouses. I know from experience they won't pass the smoke test.

If you need it, sure. But as Benjammin pointed out, from a weapons grade or massive solar flare EMP, don't count on anything you are likely to make being worth much.

And honestly, I doubt we'll ever have to find out which of the many schools of thought on EMP are the right one. You find everything from "no big deal, the gaps in modern components are too small" to "if it's got a transistor, it's smoked", and that gaumet is put out by a variety of people in the know. The truth probably lies in the middle, but there isn't enough declassified research for me to make a guess.

Just remember, if there is a big pulse, OK, you've got a XYZ, so long as you have power for it. Power lines are going to turn into big antennas, they'll have heavy spikes- the power grid is going to be at best a nightmare.

If you put a radio in a faraday cage and there is a nuclear detonation in the upper atmosphere are there going to be any radio stations to listen to?

No. But if it's a two way you can talk to everybody else who built a Faraday cage afterwards!

Sounds like TEOTWAWKI paranoia.
The Nukes are comin'!...Where?...Ahhh!
Or maybe it is truly justified, that is justified fun with aluminum foil. Don't forget that you can shield your brain from psychic alien mind probes with aluminum foil too. Have fun.

I just want to put in a quick word...I worked around nukes in the military and had to do extensive training do to that. EMP's should be the least of your worries. If you live in an area that has more than your immediate family in a five mile area, you've got bigger worries. On the other hand if you are fortunate (or unfortunate to city folk) enough to be out in the last bit of uninhabited land than I would think that you've already had problems with electronics and radio signals. Just watch the history channel and you can see that today's weapons are around 100 times more powerful than the bombs we dropped in WWII. That's the TV version. Now imagine this...a country like Pakistan that can't even keep UBL from playing hop scotch on its border has this capability.

Well, I doubt it. Maybe if you buried it in a mineral rich and moist substrate a thousand or more feet down it might work, but the field strength of a nuke based emp is going to overwhelm the ambient ground conditions enough to pretty much saturate the faraday sheilding.

We tested a pretty good faraday cage with what I called a symphony box (a capacitative multiplier that generated 114Kv). When the probe arced to the cage, the SA we were monitoring inside showed an obvious broadband hit on the scope. That was a miniscule spike compared to the saturation pulse that would be generated from an emp. The relatively high rise time will generate some serious eddy current in the screens, and before the energy can get conducted off to ground, you are going to have some serious coupling to equipment inside as the field seeks to balance itself. At most, the faraday cage is going to simply delay the spike by reactively phasing the pulse, maybe by a few microseconds at most.

I know the screen holes are supposed to suppress the eddy current inducement, but electricity does funny things at ionizing levels, and a compton wave is not something we see routinely enough to be able to predict the effectiveness of sheilding at the surface with a high enough certainty.

The bottom line is, if you want to have solid state circuits after an emp, all you need are two dissimilar metals, and you have a semiconductor junction. Got any spare change?

Hi Shadow_ooOO

I've not built a faraday cage, you don't really need to, you probably own quite a few anyway. If you want to protect sensitive electronic equipment from EMP attack just think of the priciple of the Matryoshka doll, a faraday cage within a faraday cage within a faraday cage. Your car will be an effective faraday cage and so are those aluminium camera case/tool boxes (ones with rounded corners are the best and are available in differing sizes). Just put what you want to protect in a aluminium box inside another aluminium box inside the car boot. And then if possible put your car inside a metal box garage like the metal shed in the article.

Anyway you should always look on the bright side of life. After an EMP attack, everyone will get to know their neighbours, the art of letter writing will make a return, piano sales will increase and life won't be so bad just because the internet and the phone doesn't work. It will give everyone more time to read a good book and get back into the garden to do some gardening. There is nothing really worth watching on the TV anymore anyway. Cycling will once again become enjoyable without all those motor cars on the road