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TangoFoxtrot
04-12-2012, 04:58
Home made Faraday cages, In your opinion do you think they really would work? If they are worth my time and money to build what do you think is the best type to construct?

quake
04-12-2012, 06:35
Easy way to test, is to put a radio or cell phone in your cage & see if it works. (If the cage works, the radio or phone won't be able to receive a signal.)

Imperfect test as there are some differences between radio waves and em waves, but a test that can be learned from.

Glockdude1
04-12-2012, 08:15
A Microwave oven is a Faraday cage. Place your cell phone inside, close the door and call your phone.

(don't turn the microwave on!!)

:cool:

cowboy1964
04-12-2012, 08:30
A radio test won't really prove a cage will protect against an EMP. The EM strengths are just too different by orders of magnitude. That's why EMP fries while radio signals do not.

Donn57
04-12-2012, 08:44
Yes, they will work. Yes, they are worth the time and expense (minimal) to construct if an EMP is something that is on your list of SHTF situations you are worrying about.

racerford
04-12-2012, 08:49
Faraday "cages" work on certain ranges of frequencies. Faraday boxes may work on all(?) frequencies. The size of the perforations determines frequencies they work to.

quake
04-12-2012, 09:06
Best size of perforations imo is "zero" perforations; or a solid sheeting approach.

A Microwave oven is a Faraday cage. Place your cell phone inside, close the door and call your phone.
I've heard that before but it didn't work when I tried it, so I never recommend it. Just out of curiosity, after reading your post I just now tried it again. Phone rang fine. :dunno:


Best home-made version I've found is cumbersome & inconvenient, but works quite well, using paper bags & aluminum foil. To work, a faraday cage has to be conductive around the device, but istolated from it. Put the device in a paper bag, wrap the bag well in foil (fold the edges up good & tight), then another bag, another layer of foil wrap, then a third layer of the same. That's worked well for me in my admittedly non-scientific testing. Doing it that way, a supposed "12 mile" gmrs radio inside (turned on with volume all the way up), wouldn't receive from an identical radio even an inch away from the wrapped package.

Real downside to this approach is that it's a pain to get to the device. Only things I use it for are things intended to be put back in hopefully long-term storage, and a few things in my ghb gear. Doing so to protect ghb items (like night-vision, spare gps, etc) may be excessive or 'way out there', but to some degree the same could be said of having ghb gear in the vehicle in the first place.

If I had a way to test against genuine emp I'd do so, but that not being possible, this is the best & most conservative approach I've personally come up with. Always open to new ideas.

Glockdude1
04-12-2012, 09:24
I've heard that before but it didn't work when I tried it, so I never recommend it. Just out of curiosity, after reading your post I just now tried it again. Phone rang fine. :dunno:



Mayby microwaves are built different. I have a Stainless Panasonic 1250watt oven. I placed my Samsung Galaxy Note inside and tried it. Phone did not ring.

:dunno:

Bolster
04-12-2012, 09:42
Best size of perforations imo is "zero" perforations...

Interesting post. Well my Ham Radio's "faraday" (ammo can) is getting some quake-style modifications ASAP.

My phone rings inside my microwave just fine. As casually as I could I said to my wife: "Oh, there it is, I must have forgotten it in the microwave." She was ready to have me committed on the spot and would not leave me alone until I gave an explanation. Followed by the "You're So Strange" look.

quake
04-12-2012, 11:10
Mayby microwaves are built different.

Could well be. Might be signal-strength issues, carriers, or even phone issues; no idea. Mine's a low-end LG (at&t) smartphone.

racerford
04-12-2012, 11:13
Microwaves (appliance) are designed to block microwaves Cell phones function on a number of different of frequnces based on your carrier.

What is the frequency of an atomic bomb EMP? How about a Solar Flare EMP?

RED64CJ5
04-12-2012, 11:31
Yes, they work. As others have said, there are construction/design criteria that need to be met.

Quake nailed it on the basic premise. You need to shield the device you want to protect, then basically insulate with non conductive material, then shield again.

I employ several anti-EMP technologies in my home.

First, the whole house exterior is a grounded, metal cage, independent of my interior ground. No kidding. Yes, I have windows, but their impact is minimal.

Basically I use a multi-layer approach. I cannot guarantee this will block all frequencies, as others have stated, but it certainly knocks a dent in major RF / EMP / power bombs coming my way.

Secondly, all sensitive electronics that I care about for EMP-proofness are handled in a variety of methods.

One method I like (and recommend) is the use of the aluminum/metal garbage cans. They hold a lot of stuff. The trick is to pack them in a way so that the internal compartment with your electronics is not touching the external trash can material. You need a good liner. I have tried various blankets and packing peanuts.

I do not have access to any serious test equipment that could put all my theories and practices to a 'real world' test, but I have done plenty of practical tests using my 20+ year background in radio.

Devans0
04-12-2012, 11:46
I didn't know that a second metal layer was needed. I want to find out more. FWIW, I have a metal shingle roof. It blocks signals in the attic and upper bedrooms.

I always wondered what lightning would do to an EMP barrier, would foil protect or would the heat/voltage blow right through.

Will it stop those voices in my head that I keep listening to? They can get pretty annoying, sounds like my wife.:trek:

quake
04-12-2012, 14:03
I didn't know that a second metal layer was needed...

Can’t say about “need” since I don’t know a truly accurate way to test for emp; so I just go with ‘more is better’. When testing with the gmrs radios (and department portable radio, and cell phone and AM & FM radios), more layers blocked better. Seems obvious, but good to see the principle in action rather than just in theory. Example, with the gmrs, inside a single layer of bag-then-foil, the radio would pick up from a range of 10-15 feet (these were alleged “12-mile” radios). With a second bag-then-foil layer added, it took reception down to a few inches. A third layer took it down to zero. Seeing that two worked that much better than one and three worked better than two, I went with three to be safe.

Frankly, seven or eight layers wouldn't hurt imo if it was something critical and/or hyper-expensive that you could live with leaving in seriously-long-term storage. If I had some unique, life-critical item that I absolutely wanted to protect to the absolute best of my ability, I'd do as many layers as would fit inside whatever chosen outer container (garbage can, ammo can, rubbermaid tub, etc) just to be safe. May not be necessary, may not even be beneficial or even helpful; but I figure it couldn't hurt.


Fwiw, one experiment I tried that really surprised me was with brass window screen. Not the plastic or even aluminum stuff you typically encounter, but genuine brass window screen. I took a small section of that - probably a foot or so square - and rolled it into a tube shape about 4" in diameter & a foot tall. Left the ends open, just a short section of screen tube. My dept radio has the NOAA weather channel programmed in, and leaving that channel running, just slipping the tube down around the standing radio was enough to completely kill the signal. I was very surprised at that (it was my first hands-on testing), but to be fair, we're pretty rural and the signal wasn't as strong as it probably is in some areas. Doing the same thing with a gmrs radio or cell phone had no noticeable effect on reception at all, but with the noaa, am or fm, it killed it. :dunno:


The point of all this rambling & babbling is "test stuff"; and then let us (everyone) know what you find. I'm happy if someone can learn from me, but I'm much happier when I can learn from them. :cool:

DoctaGlockta
04-12-2012, 18:18
A Microwave oven is a Faraday cage. Place your cell phone inside, close the door and call your phone.

(don't turn the microwave on!!)

:cool:

Well you got me to at least try it.

Call went through however.

sebecman
04-12-2012, 18:53
A Microwave oven is a Faraday cage. Place your cell phone inside, close the door and call your phone.

(don't turn the microwave on!!)

:cool:

I don't believ so. Oven door is glass after all and faraday needs to be metal all around...need proof please. :dunno:

sebecman
04-12-2012, 18:57
First, the whole house exterior is a grounded, metal cage, independent of my interior ground. No kidding. Yes, I have windows, but their impact is minimal.

Red, I value your opinion and expertise, please elaborate on the above..what do you mean that your house is grounded in a metal cage?

Thanks

:cool:

Glockdude1
04-12-2012, 19:28
I don't believ so. Oven door is glass after all and faraday needs to be metal all around...need proof please. :dunno:

My Stainless Panasonic microwave block the signal on my cell phone.

:dunno:

racerford
04-12-2012, 21:50
I don't believ so. Oven door is glass after all and faraday needs to be metal all around...need proof please. :dunno:

It is glass with embedded metal that is perforated. The holes are large enough to allow you to see through it, but not large enough to allow microwave frequency radiation through it.

Adjuster
04-13-2012, 00:18
Have you seen this movie? It has a pretty good Faraday cage theme to it.

The Darkest Hour

http://www.imdb.com/title/tt1093357/



/

TangoFoxtrot
04-13-2012, 04:21
Interesting post. Well my Ham Radio's "faraday" (ammo can) is getting some quake-style modifications ASAP.

My phone rings inside my microwave just fine. As casually as I could I said to my wife: "Oh, there it is, I must have forgotten it in the microwave." She was ready to have me committed on the spot and would not leave me alone until I gave an explanation. Followed by the "You're So Strange" look.

Oh your wife gives the "Your so Strange look" too?" It must be the female estrogen factor.:whistling:

TangoFoxtrot
04-13-2012, 04:29
On a more serious note, My plan was to use this huge ammo can I have. Then suspend a smaller can inside it fill 1/2 the can with liquid insulation foam let it dry. Place Items in the smaller can (wrapped in foam)then fill the other half with some other type of styrofoam or something to that effect. This way both cans never touch because of the insulating foam. Well you get my point.

Kieller
04-13-2012, 06:24
double tap

Kieller
04-13-2012, 06:27
Its hard to say exactly what would be required for a 100% EMP proof faraday cage. It will be dependent on the size/range/conditions of the emp which will affect your electronics.

My BIL designs insulation for military planes which protect against EMP. The main problem they have is that all the copper wiring and other metals within the plane 'build up' and transfer the electro magnetic charge to the instruments and sensitive electronics.

How does this help you with a makeshift faraday cage? I would:
1) Make sure whatever cage I have is grounded so that whatever charge will dissipate

2) If you use multiple metal insulation layers make sure none of them are touching whatever you are trying to protect. I like TangoFox's idea of foam, its non-conductive.

3) For something that was very vital I would have a nested faraday cage setup.


If you have a shortwave radio, it is likely to be knocked out by the EMP unless it is adequately shielded. To be adequately shielded, it needs to be kept inside of a complete metallic shielded enclosure, commonly known as a faraday cage, and preferably inside nested faraday cages. A faraday cage is an total enclosure made out of a good electrical conductor such as copper or aluminum. (Steel also works well, but it is more difficult to make a total enclosure with steel.) Large faraday cages can get extremely complicated. For small portable electronics, though, completely covering the electronic equipment in aluminum foil makes an adequate faraday cage around the equipment. The foil covering needs to be complete, without any significant gaps. Wrap the device in plastic or put it in an insulated box before wrapping the covered device in foil. (Otherwise, the foil may simply conduct the EMP energy into the device more effectively.) A single layer of foil may not be adequate. In order to enclose the equipment in a nested faraday cage, place the foil-covered device in a plastic bag, such as a freezer bag, and wrap that bag completely in aluminum foil. If you really want to protect the equipment against a large EMP, add another layer of plastic and foil. The layer of plastic need to be the thickest plastic bags that you can easily find. (They don't need to be terribly thick, but do try to find some heavy-duty bags.)

Just adding many layers of foil directly on top of foil won't do as much good, due to what is called "skin effect." I won't bother to explain skin effect here, but you can look it up if you're curious. Don't worry too much about skin effect, though. I only mention it here because many people have the misconception that when it comes to shielding, the thicker the better -- and this is definitely not true after a certain thickness is reached. Layers of shielding separated by insulation works much better. As a practical matter, though, wrapping with 2 or 3 layers of foil helps to assure that you actually have a good shield around the equipment.

Of course, any antennas or power cords need to be either disconnected or contained completely within the faraday cage.

One question that arises frequently is whether a gun safe or a galvanized trash can makes an effective faraday cage. Technically, it may not be correct to call either of these a faraday cage because they are not constructed of the best electrical conductors. A galvanized metal trash can, though, can be a very effective electromagnetic shield. The interior of the body of the galvanized metal trash can should be lined with some material to electrically insulate items stored inside the container from the metal exterior. (Cardboard probably works better than any other inexpensive material for this. Liners such as plastic trash bags may be too thin for this because of the momentary high voltages that could be induced on the exterior during an actual EMP.) Do not place any insulation at a point where it would interfere with the electrical connection between the metal lid and the metal body of the trash can. It would be a good idea to wrap items placed inside the metal trash can with a layer of aluminum foil in the "nested faraday cage manner described above.



Some good info there regarding faraday cages. Link is below for the source.

http://www.futurescience.com/emp/emp-protection.html

sebecman
04-13-2012, 08:04
It is glass with embedded metal that is perforated. The holes are large enough to allow you to see through it, but not large enough to allow microwave frequency radiation through it.

Ok that makes sense

RED64CJ5
04-13-2012, 09:32
Red, I value your opinion and expertise, please elaborate on the above..what do you mean that your house is grounded in a metal cage?

Thanks

:cool:

Our house is of metal / red-iron framed. Think of a large, industrial shop building. There are columns and beams of steel supporting the entire exterior, separate from the wood (think common, stick house) interior. The exterior is grounded via a network of re-bar and specific ground rods around the entire perimeter. It acts as a primitive cage, but obviously there are windows which do very little to shield from a strong pulse.

I will tell you this. Very little signals get in or out of my house unintentionally. For example, no cell phones work. If I disable my cell repeater with outside antenna, no calls come in or out.

https://lh3.googleusercontent.com/-83Gxdc4ksus/T4hGiXP1-yI/AAAAAAAAF4s/hqCY65rKxn4/s800/IMG_2256.JPG

sebecman
04-13-2012, 12:11
Thanks Red

Interesting, I was thinking along the lines of steel mesh embedded in concrete or something similar.

Thats a cool set up.

quake
04-13-2012, 12:42
Red -

That looks like it might be a later version from the same mfr we went with. Place out of texas; don't think they're there anymore.

Not our house, but stock photos from their old site:
http://www.talentondisplay.com/AdLifetimeFrame.jpg

http://www.talentondisplay.com/framersBeneSteel.jpg

Been in it near 15 years and loving it. Phenomenal energy efficiency (R62 ceilings & R36 walls), and won't burn, rot, shrink, warp, or get eaten by bugs. Ours causes some loss of RF signals, but not complete elimination. (We used non-foil-back board. Foil-back I'm sure would have put us in a near cocoon rf-wise.)

RED64CJ5
04-13-2012, 17:32
Been in it near 15 years and loving it. Phenomenal energy efficiency (R62 ceilings & R36 walls), and won't burn, rot, shrink, warp, or get eaten by bugs. Ours causes some loss of RF signals, but not complete elimination. (We used non-foil-back board. Foil-back I'm sure would have put us in a near cocoon rf-wise.)

Well, all I can say is the energy efficiency is hard to beat. There are several methods, but all are a lot more costly per square foot than what we did.

Our electric bills are about 60% of what friends pay who have similar square footage. I like to keep the house cool, and in the summer at 70 degrees our bills haven't topped $275. Several family members were running $600+ at the same time with warmer thermostat settings. Obviously there are a lot of factors (trees, age of construction, etc) but overall you could still put us in the apples-to-apples space.

But the Faraday cage aspect is great for me. From a ham, it is great. Fortunately the RF noise level here is phenomenal...(out in the country, no commercial or industrial complexes within 15 miles.)

TangoFoxtrot
04-14-2012, 06:58
Its hard to say exactly what would be required for a 100% EMP proof faraday cage. It will be dependent on the size/range/conditions of the emp which will affect your electronics.

My BIL designs insulation for military planes which protect against EMP. The main problem they have is that all the copper wiring and other metals within the plane 'build up' and transfer the electro magnetic charge to the instruments and sensitive electronics.

How does this help you with a makeshift faraday cage? I would:
1) Make sure whatever cage I have is grounded so that whatever charge will dissipate

2) If you use multiple metal insulation layers make sure none of them are touching whatever you are trying to protect. I like TangoFox's idea of foam, its non-conductive.

3) For something that was very vital I would have a nested faraday cage setup.



Some good info there regarding faraday cages. Link is below for the source.

http://www.futurescience.com/emp/emp-protection.html
Good info Kieller, Thank you! :wavey:

PlasticGuy
04-15-2012, 08:20
Is an all steel gunsafe a Faraday Cage?

TangoFoxtrot
04-15-2012, 08:27
It may if you can insulate the electronics you put in it from contact with the 6 sides of metal.

racerford
04-15-2012, 10:29
Is an all steel gunsafe a Faraday Cage?

Is it grounded? Mine is bolted to the concrete slab, but I don't think it is grounded.

PlasticGuy
04-15-2012, 11:00
Is it grounded? Mine is bolted to the concrete slab, but I don't think it is grounded.
No, but that wouldn't be hard to remedy. I have always wondered if a metal gunsafe would work, and if so why more people don't just put their electronics in one. More input welcome.

racerford
04-15-2012, 14:02
No, but that wouldn't be hard to remedy. I have always wondered if a metal gunsafe would work, and if so why more people don't just put their electronics in one. More input welcome.

I am curious how you would solve it.

I just did a test. 10 gauge steel safe. first I put one cell phone in the safe and called it. No signal got through. Then I kept the phone in the safe with the door open called it and it rang, then I closed the safe and it kept ringing. Tried the original experiment again, with the same result as the first time.

I am only 2-3 bars where my safe is. I can only conclude it is not the most effective faraday cage. I did not try multipple foil wraps, just a cellphone in a thick rubber case on a felt covered would shelf in a safe. It is a fire rated safe so it has folded door frame that should mean there are no straight through openings at the door opening.

TangoFoxtrot
04-16-2012, 04:48
Is grounding the key?

Carry16
04-16-2012, 09:24
I would venture that grounding is essential. Years ago when I was working at Fermi National Accelerator Laboratory a steel structure like in the photo above would have had at least a 250 mcm copper cable cadwelded to each vertical beam, then routed down into a trench around the building about 8 feet deep and cadwelded to a 1"x10' copper clad ground rod. Now this was the government so everything was overkill. If that were my building I would install at least one ground rod and use at least #2 copper to make the connedtion to a ground rod. And I would probably use bolt on lugs in place of the cadwelds. YMMV.

DrSticky
04-16-2012, 12:48
Is grounding the key?

I would think that wiring the door of the safe to the body of the safe is more important.

What I mean is that the entire body of the safe must pass a pulse from the front through the safe(as a whole) in order to skip the inside. If the door and the body isn't part of the same circuit then it wouldn't work.

My understanding is that the grounding is a plus, but isn't 100% necessary. The key is a complete circuit all the way around and a non-conductive layer inside of that. I have seen where folks have soldered wires from the lid to the body of an ammo can in order to achieve this, because the joint isn't a perfect connection (paint, oil, dirt, and rust may interfere with conductivity).

Toyman
04-16-2012, 14:35
From reading many of the replies, it appears as though many of you know nothing about EMP (http://en.wikipedia.org/wiki/Electromagnetic_pulse)'s, Faraday cages (http://en.wikipedia.org/wiki/Faraday_cage), geomagnetic storms (http://en.wikipedia.org/wiki/Geomagnetic_storm), or how microwaves and radiowaves work in the slightest bit.

With so much information about these things on the internet, it's surprising that so many people who are concerned about an EMP have done absolutely no studying of it.

For those interested in educating themselves, I suggest you start here (http://en.wikipedia.org/wiki/Electromagnetic_pulse) and then follow the links in that pages "see also (http://en.wikipedia.org/wiki/Electromagnetic_pulse#See_also)" section.

TangoFoxtrot
04-17-2012, 04:37
Oh pleaze edumacate our brains.

Toyman
04-17-2012, 06:58
Oh pleaze edumacate our brains.

OK, how about this: The blue underlined words in my previous post are called "hyperlinks". When clicked, they magically transport your web browser to another location on the internet, which results in the displaying of information. Reading of that information may also result in education. :rofl:

A second way of doing it would be to simply type the word into your favorite search engine, and then reading some of the resulting pages. :tongueout:

It would be beneficial to note that these topics are not things that can be easily summarized into a short sentence or two for people to read - it's stuff that some of us have spent years in electronics school learning. Although doing a little reading, the lay person can get a basic understanding of it.

One thing I will note is this: There is a big difference between the blocking of a radio frequency (RF) signal (such as VHF radios, cell phones, and microwaves), and the blocking of a induced electric current from a suddenly fluctuating or collapsing magnetic field.

For those still tuned into this post, I found this article that has some good information (http://www.futurescience.com/emp/emp-protection.html). <- that's one of those links I was talking about. LOL

racerford
04-17-2012, 10:49
Toyman, you gave a somewhat snarky response that linked to wikipedia, not necessarily a well vetted and authoritative source for anything remotely controversial from a science or political perspective. Why be surprised the response you got?

Actually you made a derisive blanket statement that did not indicate what is any of the responses had correct information. BAsed on the latest link (assuming it really is a authortative and correct source. would indicate that a number of things stated were correct and explains some of the observations were correct. However even it left a number of things unclear. It stated that in some instances grounding was bad..... and in some cases advocated it.

It is reasonable for people to assume that electromagnetic energy is electromagnetic energy, no matter if you call it radio frequency or lower frequency pulse on an electical line. If you will recall many are taught it is just a contium of electromagnetic energy from just above DC to an near infinite frequency.

You have massive knowledge in this area and you chose to ridicule others for their ignorance, how very childish of you; and not very helpful.

In spite of the way it appears sometimes, this is a forum to SHARE knowledge not a place to ridicule people for their ignorance and desire to learn more.

You seem to think all thinngs EMP are settled. Even the informaticle article you linked to, indicates that since we have not had any nuclear device driven EMP testing since 1962 that we can't be really sure. We can only hope the simulations were close enough.

Be nice when you can. Usually it doesn't cost much and pays many dividends.

Carry16
04-17-2012, 13:05
I'll bow to your superior knowledge on EMP's Toyman....though I doubt there is anyone who can claim superior knowledge on the subject simply because there is no actual test or documentation to prove anything one way or the other (IMHO). You could point to Kingfish, but I've seen blocks of street lights blown out by electrical storms routinely so I take the Kingfish documentation with a grain of salt, and I don't have a high level of trust in anything published by Russia, or any government for that matter.

My recommendation to provide a good ground to a steel structure follows established NFPA and NEC dictates. Residential is never held to the same standards as commercial buildings, but it doesn't hurt to err on the side of safety where electrical grounds are concerned, especially if you have an all metal building. And I venture to say grounding your faraday cage will not detract one iota from it's function. :tongueout:

That's my story and I'm stickin' to it. YMMV.


With so much information about these things on the internet, it's surprising that so many people who are concerned about an EMP have done absolutely no studying of it.

edcrosbys
04-17-2012, 19:32
The few places I've seen that had no RF in or out were built with what looked like copper mesh in the walls under the drywall. The windows had an odd looking mesh in them with a few wires around the outside of the windows. Very heavy door that had some wires going to in on the door jamb side. Also had a fairly think overhang with the doorjamb with gaskets.

I don't know much more about how it was built, but I can tell you they had a Spectrum Analyzer in there and it was flat as can be until you opened the door. They could also walk right up to you if you happen to bring a cell phone in...

Caveat:
My knowledge of Faraday cages is sparse and more in tune with TEMPEST stuff.

TangoFoxtrot
04-18-2012, 04:19
Toyman, you gave a somewhat snaky response that linked to wikipedia, not necessarily a well vetted and authoritative source for anything remotely controversial from a science or political perspective. Why be surprised the response you got?

Actually you made a derisive blanket statement that did not indicate what is any of the responses had correct information. BAsed on the latest link (assuming it really is a authortative and correct source. would indicate that a number of things stated were correct and explains some of the observations were correct. However even it left a number of things unclear. It stated that in some instances grounding was bad..... and in some cases advocated it.

It is reasonable for people to assume that electromagnetic energy is electromagnetic energy, no matter if you call it radio frequency or lower frequency pulse on an electical line. If you will recall many are taught it is just a contium of electromagnetic energy from just above DC to an near infinite frequency.

You have massive knowledge in this area and you chose to ridicule others for their ignorance, how very childish of you; and not very helpful.

In spite of the way it appears sometimes, this is a forum to SHARE knowledge not a place to ridicule people for their ignorance and desire to learn more.

You seem to think all thinngs EMP are settled. Even the informaticle article you linked to, indicates that since we have not had any nuclear device driven EMP testing since 1962 that we can't be really sure. We can only hope the simulations were close enough.

Be nice when you can. Usually it doesn't cost much and pays many dividends.

Well said racerford!:supergrin:

Jake514
04-18-2012, 06:24
Toyman, you gave a somewhat snaky response that linked to wikipedia, not necessarily a well vetted and authoritative source for anything remotely controversial from a science or political perspective. Why be surprised the response you got?

Actually you made a derisive blanket statement that did not indicate what is any of the responses had correct information. BAsed on the latest link (assuming it really is a authortative and correct source. would indicate that a number of things stated were correct and explains some of the observations were correct. However even it left a number of things unclear. It stated that in some instances grounding was bad..... and in some cases advocated it.

It is reasonable for people to assume that electromagnetic energy is electromagnetic energy, no matter if you call it radio frequency or lower frequency pulse on an electical line. If you will recall many are taught it is just a contium of electromagnetic energy from just above DC to an near infinite frequency.

You have massive knowledge in this area and you chose to ridicule others for their ignorance, how very childish of you; and not very helpful.

In spite of the way it appears sometimes, this is a forum to SHARE knowledge not a place to ridicule people for their ignorance and desire to learn more.

You seem to think all thinngs EMP are settled. Even the informaticle article you linked to, indicates that since we have not had any nuclear device driven EMP testing since 1962 that we can't be really sure. We can only hope the simulations were close enough.

Be nice when you can. Usually it doesn't cost much and pays many dividends.

^^^^What he said.

On the matter of grounding the metal housing and door, you can also install a metal oxide varistor (MOV) to better dissipate the collapsing electrical field.

Toyman
04-18-2012, 07:13
Toyman, you gave a somewhat snaky response.

It's almost comical that when I try to provide information on something, I'm seen as being snarky, but when someone replies "Oh pleaze edumacate our brains." no one says a thing, even though I tried to provide information to "edumacate" them.

Actually you made a derisive blanket statement that did not indicate what is any of the responses had correct information.

I'm sure if I would have singled out any particular posts, I probably would have been screamed at for not being nice and making someone cry.

you chose to ridicule others for their ignorance

These people are basically trying to protect their lives in case of an EMP, yet they indicate that they have done almost nothing to learn about it. They do deserve to be ridiculed, but I did no such thing.

Maybe you should look up the definition of "ridicule"? I stated only an observation about my perception of their lack of understanding of the issue - I did not ridicule their ignorance.

I simply stated how surprised I was that with so much information available, that they were showing such little understanding of it.

Some of us technical people are sometimes just "matter of fact" type of people. We don't always go out of our way to phrase stuff so we don't get everyone's panties in a bunch.

I spent a fair amount of time looking up some stuff, providing what I thought would be helpful links for people. If I simply wanted to ridicule others I would have simply made fun of them with a comment, said nothing helpful, and then left - much like some of you are doing now.

It's people like you that cause many others to not even bother to reply to a post because they know that they'll just get flamed. You read everything in the worst possible tone, looking for something to pounce on. It's called being a troll.

If I made you cry, I apologize, that was not my intention. (Now that was a bit snarky) :rofl:

I don't think we should drag this thread any further off topic, but if you wish to continue the conversation you can do so here (http://www.fishous.com/images/brf.jpg).

racerford
04-18-2012, 09:36
It's almost comical that when I try to provide information on something, I'm seen as being snarky, but when someone replies "Oh pleaze edumacate our brains." no one says a thing, even though I tried to provide information to "edumacate" them.



I'm sure if I would have singled out any particular posts, I probably would have been screamed at for not being nice and making someone cry.



These people are basically trying to protect their lives in case of an EMP, yet they indicate that they have done almost nothing to learn about it. They do deserve to be ridiculed, but I did no such thing.

Maybe you should look up the definition of "ridicule"? I stated only an observation about my perception of their lack of understanding of the issue - I did not ridicule their ignorance.

I simply stated how surprised I was that with so much information available, that they were showing such little understanding of it.

Some of us technical people are sometimes just "matter of fact" type of people. We don't always go out of our way to phrase stuff so we don't get everyone's panties in a bunch.

I spent a fair amount of time looking up some stuff, providing what I thought would be helpful links for people. If I simply wanted to ridicule others I would have simply made fun of them with a comment, said nothing helpful, and then left - much like some of you are doing now.

It's people like you that cause many others to not even bother to reply to a post because they know that they'll just get flamed. You read everything in the worst possible tone, looking for something to pounce on. It's called being a troll.

If I made you cry, I apologize, that was not my intention. (Now that was a bit snarky) :rofl:

I don't think we should drag this thread any further off topic, but if you wish to continue the conversation you can do so here (http://www.fishous.com/images/brf.jpg).

Your post did not hurt my feelings. My feelings don't get hurt by what an anonymous person on the internet thinks of me.

I provided information in simple terms in answer to questions.

I provided an observation of a simple experiment I performed in response to a question about a safe. While you posted a Wikipedia link along with no useful additional comments from your experience. You have vast knowledge from decades of experience, and you provide a Wikipedia link? Really, is that the best you can do? Why bother to post that at all.

EMP has been a topic on this forum many times. We have had people with actual experience in testing non-nuclear EMP and RF testing give very good information based on their firsthand experience, you claim to have that same expertise and you post a Wikipedia link without a comment. You don't make a simple statement that a steel container may not be effective, especially a painted one. You make no comment about the validity of the foil and insulation wrapping suggested early in the thread.

As for signaling out incorrect posts, that is exactly what you should have done, instead a blanket statement that gives no information as to which your experience, education or knowledge would indicate are not effective.

You are responsible for how your communication came across. If it was not received as you intended, you should clarify. At least a few others perceived your communication similar to the way I perceived it.


You remind me of my father in law that is an internationally recognized expert in a particular field. He is quite technical and "matter of fact" (read that he has no concern for other people). He has poor interpersonal skills and likes to prove to everyone that he is smartest person in the room and often demeans his wife and daughter in the process. My wife takes great delight when he is put in his place and shown he is not always the smartest most knowledgeable person in the room on every topic.


Thank you for trying to provide information and input on the topic. Don't be discouraged from posting useful information. Or even snarky comments if your intent is to be humorous. Next time just be aware the perception of your attitude by your audience will affect how it is received and the credibility of your information.

Good luck in the future.

nightwolf1974
04-18-2012, 15:09
31 gallon trashcan, lined inside with paint on bedliner materail. cheap and effective!

TangoFoxtrot
04-19-2012, 04:31
It's almost comical that when I try to provide information on something, I'm seen as being snarky, but when someone replies "Oh pleaze edumacate our brains." no one says a thing, even though I tried to provide information to "edumacate" them.



I'm sure if I would have singled out any particular posts, I probably would have been screamed at for not being nice and making someone cry.



These people are basically trying to protect their lives in case of an EMP, yet they indicate that they have done almost nothing to learn about it. They do deserve to be ridiculed, but I did no such thing.

Maybe you should look up the definition of "ridicule"? I stated only an observation about my perception of their lack of understanding of the issue - I did not ridicule their ignorance.

I simply stated how surprised I was that with so much information available, that they were showing such little understanding of it.

Some of us technical people are sometimes just "matter of fact" type of people. We don't always go out of our way to phrase stuff so we don't get everyone's panties in a bunch.

I spent a fair amount of time looking up some stuff, providing what I thought would be helpful links for people. If I simply wanted to ridicule others I would have simply made fun of them with a comment, said nothing helpful, and then left - much like some of you are doing now.

It's people like you that cause many others to not even bother to reply to a post because they know that they'll just get flamed. You read everything in the worst possible tone, looking for something to pounce on. It's called being a troll.

If I made you cry, I apologize, that was not my intention. (Now that was a bit snarky) :rofl:

I don't think we should drag this thread any further off topic, but if you wish to continue the conversation you can do so here (http://www.fishous.com/images/brf.jpg).


Toyman you didn't hurt my feelings because I have a black heart to begin with. Its just that you came off like the rest of us are just idiots so, you got the proper response you deserved. So don't dwell on it. Just be a little more respectful. ...oh and BTW....:tongueout:

TangoFoxtrot
04-19-2012, 04:33
31 gallon trashcan, lined inside with paint on bedliner materail. cheap and effective!

Thanks for the suggestion. This was the route I was thinking and was going to use insulating foam instead. My only problem is finding a metal garbage can.

Donn57
04-19-2012, 10:17
My only problem is finding a metal garbage can.

Lowes and Home Depot both sell the same 31 gallon galvanized steel garbage can for about $25.

janice6
04-19-2012, 10:24
I have had Faraday cages constructed cheaply overnight from home improvement store materials to shield EM from Superconductive sensors capable of sensing One Flux Quantum..

Absolutely, they will work.

quake
04-19-2012, 11:30
...constructed cheaply overnight from home improvement store materials...

Specifics...? Thanks

TangoFoxtrot
04-20-2012, 04:38
Lowes and Home Depot both sell the same 31 gallon galvanized steel garbage can for about $25.

Thank you! But never seen them. I'll have to inquire about them next time I'm there.

TangoFoxtrot
04-22-2012, 07:20
Ok my lastest Faraday project completed. I purchased a 31 gallon galvinized trash can. Filled it with liquid foam. Then I inserted a wire cage about 3 inches in from the diameter of the can. Then I placed a sterdy plastic container dead center. Inside the lid of the can I lined it with foam and let it dry a bit. I fastened the top of the cage to the lid so when the lid goes on it makes a connection to the innner cage. Then I have #2 copper wire bolted to the trash can and connected to a grounding rod 4 ft deep. The bottom line is the container which will house my electronics is in plastic container surrounded by foam then a wire cage more foam then the galvined trash can.

I don't know if this would work or not but for a $50 dollar investment why not try. If it does work I will have plenty of lithium batteries, an emergency reciever and 3 two-way radios.

Can anyone think of anything else I need to place in there?

Tom Kanik
04-22-2012, 10:06
I use a 55 gallon steel drum with a snug-fitting lid, and styrofoam to insulate contents from metal contact.

TangoFoxtrot
04-22-2012, 15:41
Hey Tom that sounds as good as any other idea out there. I may have gone a little overboard.

Tom Kanik
04-25-2012, 16:29
Thanks! I put in a small b/w t.v., crank radio, power inverter, and other items and still have room. It sits in my basement, nice and cool.:cool:

janice6
04-25-2012, 16:34
Specifics...? Thanks


Two by four frame on two foot centers to staple to. 1/4 inch hardware cloth covering both inside and outside. Door construction the same with the hardware cloth overlappint the door frame studs and the door screen also overlapping the door studs. You want the door screen to make good electrical connections all around the door. Every edge must contact the adjacent edges, no gaps.Inside and outside independent.

Don't forget the floor too.

Donn57
04-25-2012, 17:08
Hey Tom that sounds as good as any other idea out there. I may have gone a little overboard.

Given that if you need it, there is no room for error, I think going a little overboard is an excellent approach.

TangoFoxtrot
04-26-2012, 04:10
Two by four frame on two foot centers to staple to. 1/4 inch hardware cloth covering both inside and outside. Door construction the same with the hardware cloth overlappint the door frame studs and the door screen also overlapping the door studs. You want the door screen to make good electrical connections all around the door. Every edge must contact the adjacent edges, no gaps.Inside and outside independent.

Don't forget the floor too.

Sounds like a good plan too me.

TangoFoxtrot
04-26-2012, 04:11
Given that if you need it, there is no room for error, I think going a little overboard is an excellent approach.

Well a solar flare is something that could happen in an instant. So why not be ready?:supergrin: