06 May 2012

The home Faraday cage

This is one of those things that if you look at how our sun acts up giving us lovely Coronal Mass Ejections that play havoc with electrical systems or if you are worried about a nuclear EMP and wish to have some electronics working after the event, that you will want to make or build: a Faraday cage.  There are lots of other things you can do with such a object, but for modern home use it usually goes into one of those 'You know one of these events is likely to happen...' sorts of thinking.  If you are preparing for an unknown future and want some ability to do some of what we consider modern functions, you will look at utilizing such a thing as a Faraday cage.

A Faraday cage can be made of mesh or sheet metal that is conductive to electricity, and it acts to distribute electricity over its surface inducing an opposite charge on the other side of the conductor, so they cancel out, thus canceling out the wave that induced the current.  It is a hollow conductor and what is on the inside, so long as it is insulated from the conductor, will not receive any of the energy of the incoming wave or charge change event (like lightning).  The aluminum container that is an aircraft is a Faraday cage in that it conducts something like a lightning strike around its exterior surface so that the strike goes over the skin of the aircraft and comes out the bottom of it, not touching the electronics or passengers on the inside.  With that said there are still some openings in an aircraft that allows it to receive other electromagnetic waves, so it isn't a perfect example of this.  A car can be struck by lightning and the lightning will flow over the surface of it and head towards the ground, leaving the passengers (if present) unharmed.  I've actually witnessed one of those events first hand during a mild storm that didn't have any lightning associated with it, but that flash and boom a block away going around a car was an amazing sight.

There are lots of ways to create a Faraday cage, including using a 'space blanket' of aluminized mylar, to go around an object to protect it.  Make sure anything inside is insulated from the coating so that the charge flows around the surface of the protection.  You can also connect the container to a grounded object (say the little screw holding on the faceplate on a three prong electrical outlet) and you can drain off a charge to ground.   During a CME event, once the worst of the storm has passed, you may need to cut the ground due to induced ground currents flowing back up the wire... although your circuit breakers or fuses in the home will probably go first.

In your home are a number of Faraday cages, starting with the microwave oven.  It uses short wave radiation to induce movement in molecules and anything outside needs to be protected from this.  Thus anything on the inside of a microwave oven is in a Faraday cage.  A clothes dryer with closing metal door is also one.  All metal breadboxes with only tiny holes or mesh to allow air passage would also qualify.  Duct tape works passably well to create a Faraday cage, if push comes to shove, so something that might not be such a cage to start with could be turned into one so long as there is electrical conductivity around the surface of the object.

Since the cage is an enclosure that is aimed at stopping electromagnetic effects requires that any doors have lips to them or that their frame have interior lips to force an indirect passage into the interior.  You can use a flashlight to demonstrate this, and if you see no direct light from it when the doors are closed, then you have closed off the interior from electromagnetic waves.  A single 90 degree bend ought to do it.

To put one together I had some criteria and wasn't all that keen on doing sheet metal fabrication and welding... since I don't have any sheet metal brakes or welding equipment.  That meant using the next best thing: a purchased metal cabinet.  There are scads of designs, sizes, shapes, colors, and all sorts different manufacturers out there, and your needs will dictate sizing to you.  One of the prime criteria I had was that it fit a modestly tall, watercooler sized device in it, and that drove all later decisions.  If you don't care about looks, then big and cheap works just as well as anything else, and that is what I went with:

EMP_CME_ 003

I got that from Global Industrial and the manufacturer is Edsall, although it was only presented generically on the site.  It is spec'd at 130lbs for delivery, but it was strapped to a pallet and the entire thing was a beast to get up two sets of half-flights of stairs.  Much sweating and recovery time involved.  It arrived a bit dented, battered, scratched and in the general condition I expect industrial freight hauled stuff to arrive in.  I had to bet in the sheet metal top rear corners with a dead-blow hammer and do some tapping with a rubber mallet here and there, as well.  It is of the insert tab with a few machine screw bolts used to put it together and the doors are a beast to get on if you are doing it alone.  One person in good physical condition should be able to get it done in a day, two people in only an hour or two... alone and having some physical problems, it will take you a bit longer.

The prime problem with the slightly dented condition, particularly of some of the interior parts that were to match up, top to bottom, is that they didn't match up all that well and left gaps between the bent sheets.  If you have a tap welder, you can fix that up in no time at all... and any welding rig should be able to take care of other gaps from shipped condition.  I stuck a radio on FM inside and it still got reception... not great reception but not the static I expected.  AM gets through as it is just changes in amplitude of waves not variations in frequency... growing up I could go into the basement of a neighbors house, inside the enclosed root cellar that had a good half foot of dirt all around and still get AM signals.  You care more about the changes in frequency than slow variations on a wave, as it is those changes that induce a current.

Now to address the gaps and places where the slot/tab arrangement left openings, I could have used ever reliable, somewhat conductive from the right manufacturer, duct tape.  Instead I went with something made for the purposes of blocking out radio frequency changes:

EMP_CME_ 004

That non-grey shiny stuff is aluminum tape.  You can get copper tape, stainless steel tape, bronze tape... but aluminum is preferred as it doesn't oxidize at all quickly.  And if you need to make tinfoil hats, you can make one with adhesive properties to more properly affix it to your hair... which will come out with it, of course.  Wherever there were tabs or seams, I used this stuff.  I did the tops and bottoms of the doors to get a set of full 90 degree turns, and put little pockets around the lock and upper locking bar opening as well.  Along the top I did a 2/3 double over of the tape and used the last third to adhere it to the lip above the doors.  After I got done with the worst of it, I shut off the lights and used a powerful flashlight on the outside to find direct beams coming through the small places that I missed the first time.

I also spent time to put a small ground cable on that I attached to a bolt in back on the bottom and hooked up to the center of a nearby outlet:

EMP_CME_ 005

I did a voltage check between the ground wire and the third prong of the outlet to make sure there was no active voltage leaking through, then did an Ohm meter test and came up with 0.5 ohms of resistance between the exposed lead on the wire and the third prong.  That third prong is connected to the metal box behind the outlet, and the screw connects to the metal box and the lead wire connects to the screw.  Basically, within the limits of the cheap multi-meter I got free from Harbor Freight, there was little resistance between the lead wire and the ground.  Between the front of the cabinet and the end of the lead wire I got around 15 ohms of resistance, which was from the tape to the cabinet and then to the wire.  That isn't half bad, actually!

I put a radio in set to a strong local FM station and it was strong until it got part way in the cabinet, then started to get static and once I closed the doors it was all static.  I've been putting in some of the minor stuff that helps after a major EMP or CME event, and a few big pieces will go in the bottom next to the solar array... mainly its rectifier/battery arrangement which is made to run the AWG off-grid all on its lonesome.

Total cost for the cabinet, tape, and getting a decent dead-blow hammer from Harbor Freight, plus freight to get the cabinet to me disassembled was around $500.  Perhaps I could have done better by scouting around some of the local scrap yards or hitting up Salvation Army or Goodwill... but I don't have a lot of energy and what time I do have during the day needs to be put to good use.

This project has interposed itself in front of my woodworking projects due to priority.  Those projects are on hold until I can get a reliable outdoor shelter up to do the finishing of the wood.  So next up is the methanol chiller system to test out.  Once I get a piece from the folks at Shelter Logic for my shed-in-a-box, I'll get that up and get back to finishing my workbench and then start on a router table/workbench extension.  After that I need to make a few other pieces like miter saw stand, grinder stand, and a final finishing/small work/gun tinkering bench.  Somewhere in there I would also like to make a real gun cabinet, too...

There you go!

More of the stuff I do instead of blogging because I detest repeating myself, and I hate having gloomy future prospects turn into reality... and if that is going to happen, I'll need this other stuff to survive.  And if you want to extend from my terrorism and organized crime work, you might want to catch Rumors of War III.

04 May 2012

Jigsaw woman

I learned whilst reading at Hot Air of the Obama campaign pushing "Julia" as a great reason to re-elect the President.  "Julia" represents all that government does for women, from cradle to grave... save that liberalizing abortion, making abortions cheap, and not putting any stigma on them means that "Julia" probably wouldn't exist because her mother saw her as a 'burden'... but lets say you are unlucky enough to be born and you are female, you would take some part in "Julia".  But not all of "Julia" because she doesn't exist, like President Obama's jigsaw woman of a girlfriend in Dreams from my Father.  Still it is telling that the portrayal of "Julia" is that of being dependent upon government for every little thing... which did prompt me to write at the HA post above, the following:

You go girl!

Go to the government to get your check!

Go rush to get AFDC when you can’t just find someone decent to live with, but can’t stop having fun, because the government is always there to help!

Go rush to the abortion clinic if you really didn’t mean to let him go that far!

Go be a wilting hot house flower taken out into the real world that forever needs protection from tyrannical government!

Government is your friend!

Government will give you things!

Government will be your master because that is what you always wanted, never to be free and always dependent on others for your life!

You go girl!

Go away.

Find some nice Communist system that will tell you how many children to have and dictate the rest of your waking life to you.

That is what you are asking for.

So go get it someplace else.

You go girl!

Or grow up and become a woman and take responsibility for your life.

Go and become a woman who can stand on her own two feet and tell the government you don’t like the bling on its manacles, no matter how free they are they are chains.

That is when you stop going and start taking a stand for yourself.

Do that and I will stand beside you for freedom, for liberty.

ajacksonian on May 3, 2012 at 1:59 PM

Women will have to start making up their minds: are they independent, free women who do not rely on tyrannical government to provide 'safety' throughout life as, in that doing, they can no longer be independent in spirit or mind, or are they a burden to society, to government and government only protects them out of pity and sweet talks them into not reproducing any more.

It isn't about gender or sex, of which there are differences between those words, but about being free to stand for yourself and, if necessary, by yourself for your own life.  Government is not Prince Charming riding in to save you, but to make you a servile peon forever begging for handouts, gifts and protection... at the cost of your own moral spirit and soon, very soon, all other freedoms as well.  You can't say, both, 'hands off my body' about abortion and then give up your body entire to government sponsored health care for, the moment you do, your choices about your body are no longer your own and if government is doing the working for you it gets a say in the outcome.

You cannot support a 'You go girl!' attitude and then, at the same time, turn around and seek more government intervention in society to 'do good'.  That is the responsibility of the 'You go girl!' girl because, by being that sort of girl, she is willing to take up being a woman with the full rights, responsibilities and perils of being a free woman able to make her own way and live life on her own terms.  Put in the broker of government and you are no longer a 'You go girl!' girl seeking to be a woman, but a child seeking to never face life, never to take part in the hard decisions in life and to accept that government must rule your life because you are unable to live without it.

This is not about the poor, the 'disadvantaged' (whatever that means), the sick (who were already being taken care of long before any government 'help' arrived), or even the mentally ill as it was the Left who led the way to close down asylums and not reform them, instead.  If you are expecting government to pick up your part, then you must face the fact that someone ELSE is paying your way and that you are not free in that doing.  That someone else isn't just the government, but the taxpayers... of which these are heading towards a minority in this Nation.  The piper is being paid by someone else and your tune is called for you and you can forget this 'follow your muse' business as your muse has been kidnapped, bound, gagged and is now held for ransom by government which will communicate what your muse wants to you.

Isn't that nice of them?

You can be a 'You go girl!' woman and expect... no DEMAND... equal treatment under the law not just for yourself but for all citizens of these United States.  That means no shelter for you, no shelter for big business, no shelter for cronies, no shelter for politicians, no shelter from life and no shelter from failure.  When you do that you are no longer a hothouse flower that must be coddled and sheltered from minor changes in temperature or humidity, but a hardy flower able to take the elements, bask in the sunlight, persevere through storms, spread her seed and appreciate the free life of liberty and the seasons of one's life.

That takes courage.

"Julia" is a coward.

I have no pity for "Julia" as she is a slave to an ideology and too cowardly to say 'Screw this, keep your money and your forms, I would prefer to starve, alone, than be the slave of government'.

The pathway being offered is clear by President Obama, and he does believe that women are, at heart, cowards.

I know better.

Women are the fastest growing segment of gun owning America today.

These women are CITIZENS of a free country willing to take up arms in self-defense against a world turning against freedom and liberty.

I salute these women, my fellow free citizens who dare to exercise all their rights responsibly like good adults should.

Those women... well... I'll see you at the range!

01 May 2012

Humor when it is just mean

Consider the following purported joke by President Obama during the White House Correspondents dinner on Sarah Palin:

Source: WTSP

"Even Sarah Palin is getting back in the game, guest hosting on the Today Show," Obama began.

"Which reminds me of an old saying... what's the difference between a hockey mom and a pitbull?"

"A pitbull is delicious."

Yes the humor took me a millisecond to register and then that reaction got forced out of the way by the next millisecond's response:

From personal experience I take it?

The Obama eats dog meme is not one that anyone expected to appear, although it did appear in one of his autobiographical memoirs it too Jim Treacher to actually read the book and recognize the inanity of the Romney 'dog stuck on roof of car' meme by showing up with the Obama 'dog stuck on roof of mouth' meme.

There is self-deprecating humor and it takes a light touch to pull it off along with a bit of verbal fortitude.  The pit bull tasting delicious isn't that. I know good jokes, and this one by President Obama isn't one of them.

For a joke to work it must be relatively direct and have no question that the punchline is, indeed, the end of the joke.  A double-entendre meaning for a risque joke is a great way to end a joke, as well.  This joke doesn't have that, either, as the second millisecond left me feeling queasy.  Very queasy.

Yes it was a joke that was mean-spirited, no question about it.

But the follow-on millisecond removes the humor from it as it conjures up mental imagery that is just... disgusting.

President Obama is speaking as if from personal experience to do the comparison, trying for self-deprecating but missing that mark by just a hair.  You DO have to have that as the joke basis to make it 'work', or not work as the case may be.  It is directly part of the joke framework in the personal experience/comparison realm, and you have to be prepared for the audience to accept that you are capable of doing that personal experience to make it funny.

Trying to play off of someone else's joke to make your own takes years of experience, skill and actually making sure you don't trip over any hidden landmines.  Trying to defuse a minor scandal about yourself, to deflect criticism, and show you are a good sport all at the same time means you have to do some level of owning up to it.  President Obama misses that mark, as well.  So close and some people are more than willing to laugh and then wonder why they are laughing.

Consider the basis is a personal experience/comparison self-deprecating joke, made at the expense of someone who isn't there and can't respond.

Going over the top is a landmine.

Now we have the dual imagery of President Obama speaking from experience of eating a dog and eating a hockey mom (Sarah Palin's original personal experience/comparison joke was about hockey moms of which she considers herself one).

Think about that for just a moment.

Getting a bit queasy?

What are you left with at the end of a personal experience/comparison joke like that?

1) Cannibalism.  The direct meaning of eating.

2) A perverted sexual act with a dog.  The double-entendre meaning of eating, often used in jokes with a rimshot at the end.

Neither is acceptable as an underlying basis of a personal experience/comparison joke.

This is mean-spirited humor, for sure.

The actual joke, however, isn't self-deprecating but self-degrading.

In front of journalists who laughed.

Was it a funny joke?

Well if your first millisecond response was to laugh, then it obviously worked with you.

If you felt dirty the moment you started laughing, then you realized that the joke is on you.

Good luck in keeping the imagery that the underlying joke premise conjures up out of your head.  That is all part of learning to accept self-degradation as a norm in society.   And that is just mean any way you cut it.