Total Blackout: How To Tell If An EMP Has Happened

Think about this scenario: suddenly, all electric devices stop working, and your first thought is that the power grid is down due to a temporary malfunction. You think that everything is going to turn back to normal in minutes, but six hours later you’re still in the dark. Is this just a simple blackout? Or the feared EMP has happened?

There is at least one way to get an easy answer. All you need to determine whether you are experiencing a regular power outage or an EMP are only three transistor AM/FM/ Shortwave radios.

Find out how this works in the following article.

How to Apply the Three Radios Method 

Using three transistor AM/FM/Shortwave radios, an improvised Faraday cage and a simple SOP, you can determine whether you are experiencing a simple blackout or an EMP and if it is an EMP, whether it is geomagnetic or nuclear in nature.

Let’s see the steps that you should take to find out if the EMP is the one that caused the blackout:

  1. Tune the three radios to your local emergency frequency.
  2. Plug one into a grid-connected power outlet and fully extend the antenna. It does not matter if the power is on or 1
  3. Run the second radio on batteries with the antenna fully extended.Radio 2 - Running off battery with antenna extended but not plugged into a wall outlet
  4. Wrap the third radio in a non-conductive envelope and store it (turned off) in a Faraday cage.Radio 3 - Turned of and stowed in a Faraday bag or non-conductive lining and stored in a Faraday cage

After the power goes out, check the first radio. If you hear your local radio station, the outage was probably not caused by an EMP or it was a very minor one.

If the first radio is dead, proceed to the second radio which runs off batteries and is not connected to a wall outlet. If the second radio works, the first radio is likely a casualty of a geomagnetic EMP, but it is possible that it may have succumb to a spike, surge or other power problem outlet caused by a blackout.

If it was a blackout, you should still pickup radio stations since they have backup power. If it was a geomagnetic EMP, the radio will still function, but many local radio stations many not be transmitting because they have been affected by the EMP or because they were intentionally shut down to reduce the effect of a geomagnetic EMP since there is often forewarning.

In either case, you may be able to receive shortwave transmissions from outside the affected area since they travel very great distances. If you are able to receive transmissions, listen for news as to the cause, scope and expected duration of the outage. In a large solar storm of long duration, the second radio will still work, but it may be a day or so before you begin receiving transmissions again.

If the second radio is also dead, there is a significant probability that you have experienced a nuclear EMP. Remove the third radio from the Faraday cage. If the electromagnetic shielding provided by the Faraday cage is sufficient, and there are no leaks in the shielding, the radio should work.Baygen FreePlay Radio

Depending on the extent, duration and repetition of the use of nuclear weapons, just realize that after a nuclear EMP, it will take several hours before shortwave transmission return to normal since the upper atmosphere will be disturbed and that subsequent nuclear EMPs could destroy the radio once you remove it from the Faraday cage.

The three radios should be known, good AM/FM/Shortwave radios, but you can use cheap models for the “victim” radios. The certainly of this experiment with a group of three radios will not be absolute, but it will give you a reasonable degree of certainty.

Repeating the observations with other radios in your community, you can arrive at a greater degree of certainty about what is happening.

Why This Method Works

In order to understand the significance of geomagnetic vs nuclear EMP, and why this type of experimentation works, you must first understand that there are two main types of EMP: EMP caused by man and EMP which occurs naturally.

Of the natural origins of EMP, the type scientists believe is the most probable comes from our sun, when it spits out a CME that lobs an electromagnetic solar storm which intersects with the earth’s orbit. It interacts with the Earth’s magnetic field, resulting in geomagnetically induced EMP.

This type of EMP will not affect things that are not plugged into power lines, phone lines or other long conductors which run parallel to the surface of the Earth (and consequently parallel to the Earth’s magnetic field) and essentially act as EMP antennas.

So, an EMP that originates from the sun, should not affect cars or battery-operated microelectronics that are not plugged into a wall receptacle, but they can, and do cause blackouts.

A blackout caused by a geomagnetic events could affect an area as small as a portion of a city or county or could be so large that it affects entire continents or anything in between. A protracted geomagnetic event or EMP tracing its origins to sources outside our solar system or even our galaxy, could conceivably knock out every electrical grid on Earth, but we are most comfortable believing that the chance of that happening is so infinitesimally small that is unreasonable waste time considering it.

But, what people are comfortable believing does not always line up with reality.

Let’s say we accept the optimistic view that in all probability, all naturally occurring EMP’s in our lifetime will originate from the sun. When EMP originates from the sun, you may very well receive advance notice. In this case, power companies should preemptively shut down power plants in the area the EMP will affect, de-engergizing the grid, to some extent, and helping to prevent cascading failures and help limit the effect of the EMP.

In a best-case scenario, this type of EMP could just cost us a big pile of money and cause a temporary, possibly self-inflicted, blackout of limited scope … no airplanes plunging out of the sky, nuclear meltdowns, freeways instantly transformed into parking lots or other catastrophic consequences that Hollywood loves to depict.

In a worst-case scenario, a large solar storm will destroy the grids large transformers which are all custom-built and have lead times measured in years. The world lacks the production capability to replace them in less than years. This would be complicated by the fact that no one knows how to rebuild the grid from scratch and reboot it.

There is not book or class on the subject. The grid was built one piece at a time and grown slowly. There is no template for patching it back together after such an event. A large solar storm connecting with the Earth is inevitable. It is not a “maybe.” It has happened before and will happen again.

Behrens Locking Lid 10-Gallon Steel CanSo how do you get any forewarning of a naturally occurring EMP? If you have your feelers out, you may very well receive advance warning via our emergency communications channels since equipment constantly monitors the sun.

If you do not hear about beforehand, other folks probably would, but even if you were alone, you could deduce that it was an EMP and not a garden-variety power outage by the fact that it would be accompanied by an interruption in RF communications.

So when in doubt, grab a transistor radio and tune in to your local emergency station. If the radio seems to be working, but the station is off the air, your area may have experienced an EMP of natural origin but may still be able to receive stations transmitting from farther away. Determining the scope and duration will require more a more persistent intel collection effort on your part.

Man made EMP occurs when nuclear weapons are detonated high enough in the atmosphere to excite high energy electrons via Compton Scattering. This results in a thousand-fold increase in the EMP that would normally accompany such a nuclear detonation. EMP theory is common knowledge available to anyone. Specific weapons programs and testing is all classified, but it would be beyond naive to think that both we and our enemies have not developed super-EMP weapons.

Outside game theory, it may not possible to accurately predict the probability of when EMP weapons will be used, but rest assured that our enemies have been developing them … likely for 50 years or more.


This article has been written by Cache Valley Prepper for Survivopedia.

Written by

Cache Valley Prepper is the CEO of Survival Sensei, LLC, a freelance author, writer, survival instructor, consultant and the director of the Survival Brain Trust. A descendant of pioneers, Cache was raised in the tradition of self-reliance and grew up working archaeological digs in the desert Southwest, hiking the Swiss Alps and Scottish highlands and building the Boy Scout Program in Portugal. Cache was mentored in survival by a Delta Force Lt Col and a physician in the US Nuclear Program and in business by Stephen R. Covey. You can catch up with Cache teaching EMP survival at survival expos, teaching SERE to ex-pats and vagabonds in South America or getting in some dirt time with the primitive skills crowd in a wilderness near you. His Facebook page is here. Cache Valley Prepper is a pen name used to protect his identity. You can send Cache Valley Prepper a message at editor [at]

Latest comments
  • Or,you could try to start your car.If it does nothing ,and nothing from AM or FM, EMP!

    • Rick,

      Thanks for reading and commenting.

      Geomagnetic EMP would not disable a car. NHEMP may or may not disable a given vehicle based on model, year, orientation, distance and many other factors.

  • Why didn’t you store all 3 radios in a Faraday Cage? A Faraday Cage can be as simple as wrapping the item in aluminum foil and making sure that all edges are rolled together to prevent any gaps. The tiniest gap will allow EMP waves to enter. Taping the seam would also be a good idea. When your ‘regular’ RF source, a daily radio, tv, computer, etc. fails to respond, THEN take a protected radio out and test.

    • Bill – a layer a tin foil would barely protect against the even slightest EMP much less a dedicated EMP producing weapon designed to overcome military/heavy civilian electronics ….

      Besides – you don’t even mention the need for an insulating layer between the electronic device and the EMP pulse conducting tin foil layer – Where’s the protection?

      Wrap your storage electronics in a non-conductor material like poly or paper – enclose them in a totally enclosed heavy metal container like a metal garbage can …. your electronics THEN stand half a chance

    • Bill,

      I didn’t put all three radios in Faraday cages because the objective is to sacrifice one or two of them in order to determine whether the blackout was caused by EMP and if so, whether the event was geomagnetic or nuclear in nature.

      Thanks for commenting!

    • Bill,

      I didn’t put all three radios in Faraday cages because it is worth sacrificing a radio or two in order to know what has happened.

      Thanks for reading and commenting!

      • Hi CacheValley,
        I’m new at prepping and getting a lot of different ideas and opinions about everything, everything!! Can you tell how to make a Faraday Cage, please. How big?? What should go in it? Just bought solar panels and a small unit? Will it fry? Can it be protected? How? Is there any way to protect my Prius? I have an old track hone. Is it worth it to put it in a Faraday cage.? Would a microwave really work?
        Many thank? I have a lot of questions. This one is most pressing right now?

        • Hi Lynn,

          I have an article coming out in the next week or so that will detail three Faraday Cage builds and in that article, I will like to some of my others articles on the subject. Read those and you should be off to a really good start. If you still have questions after that, please contact the editor with questions and I’ll answer them.

          How big will be determined by what you need to store. You may want more than one if you have a lot of stuff to store.

          Solar Panels are vulnerable, especially those with integrated charge controllers. I covered solar panels here:

          and here:

          As for your Prius, that would be about the most difficult car to shield from EMP that I could think of. It would be cheaper and easier to buy a spare vehicle and protect that. He are some ideas:

          Microwaves do have a some EM shielding built in to make sure they cook your food instead of you, but the thing most people have at home that would provide the most shielding is probably an aluminum pressure cooker lined with a non-conductor.

          Thanks for reading and the questions!

  • This is good information. Thanks for sharing it. Anything that can reduce unreasonable fear is a good thing. That is unlike so many of the fundamentalist Christian groups who were saying that our world as we know it was coming to an end yesterday to boost sales of their products. I wonder if they will now take a note from ISIS, have themselves stoned publically, and post videos of it on YouTube for our general viewing pleasure. Somehow I doubt it, but I have no doubt at all that they will find a new date for the “sheeple of God’s pastures” to freak out about to boost more sales rather than giving good strategies like your’s to prevent the spread of panic.

    • Thank You Dr Alford,

      For me, emergency preparedness is about becoming as antifragile as possible … to be strengthened by volatility, change and opposition as opposed to being damaged by it or simply unaffected. I think the most common type of fear is fear of the unknown and it is typically displaced by knowledge. Once we are educated and trained, we are busy doing what needs to be done and have less energy to waste as fear or worry.

      I am very grateful for for life and do not wish for death, but I am definitely not consumed by fear. I ink that is a negative Hollywood stereotype of Preppers. Unfortunately, that’s where some folks get their entire paradigm of emergency preparedness. … but we’ll set them straight over time. ; )

  • Personally, I believe that it is fairly unlikely that some enemy would launch a preemptive EMP attack on the USA. After all, it would be an overt act of war.

    On the other hand, if the US were to experience an economic collapse or other catastrophe first, our enemies might jump at the opportunity to finish us off with an EMP.

    • That’s true Malcom. Any foreign nation, like NK which comes to mind first since it is the most unstable mentally, will immediately induce total self destruction upon itself if they even tried that.

      Most so called ‘experts’ and insiders only Religionist terrorist groups would try such an insane act but they don’t have the technical sophistication to create and launch even one formidable enough HEMP weapon. They need a large missile platform which would be immediately spotted way ahead of time in the construction process. Since there are already several ‘misplaced’ nuclear bombs on the international black market, or at least enough material to make a home made suitcase bomb, that would be the likely weapon of mass destruction used by a terrorist group, whose goal, after all, is more to create ‘terror’, than actually destroy lives and property. And nothing they do can compare with the retaliatory horror of an Aircraft Carrier battle group’s immediate response to their home base.

      My personal and well researched ‘insider’ fear is something far more horrific in both its initial destruction and scope of future harm to our society.

      A False Flag event involving massive grid shutdowns to cause widespread panic and social breakdown as a justification for national martial law, when the ‘need’ finally arises. Far easier to accomplish and far more damaging than any HEMPs or normal Solar Events could ever cause.

      ‘They’ve’ already covertly ‘tested’ the viability of the plan a couple years ago in California, right under everybody’s noses with barely noticeable news reaction. I immediately knew what it was. And I knew what the G wanted everybody to ‘think’ it was. Sort of a ‘pre-programming’ of the ‘innoculation effect’ syndrome. (Few people know this unless you’ve been there, done it, but this is actually taught in places like JFK Special Warfare Center and other CIA’spycraft’ tutorials)
      I’m not mentioning details here anymore so as not to give lone wolf morons any brainstorm ideas.

      But the best part of this methodology, as opposed to an EMP weapon is that it then can be blamed on all those former Americans Patriots who are now considered radicalized (no need to mention any particular relgionism or anti-G group because almost all of us can now be ‘determined’ to be ‘aiding and abetting’ terrorism in some way shape or form due to the latest new law now allowing this determination without due process and merely by simple discretion of the Secretary of state and AG by administrative decree) domestic terrorists subject to widespread search and seizure and internment.

      Between murderously insane religionists, Murderously corrupt government, and one of the worst serial killers in the world, Mother Nature, to quote an old aphorism…

      “It just don’t look too good for the home folks anymore…”

      • That is entirely possible, but it wouldn’t need to be nation state. After all, the first nuke exploded high enough to trigger the Compton Effect was the Hardtack Yucca shot, which got it’s payload to altitude using a balloon.

        Another common fallacy is that it would take a thermonuclear weapon to trigger an EMP. Over 100 small yield tactical nukes were “missing” from the Soviet arsenal after the breakup of the USSR and highly enriched uranium has been seized at checkpoints searching for drugs. Enough material to make dozens of nuclear weapons has been caught by accident in a single stop. Imagine how much didn’t get caught!

        It’s just easier for most folks to not think about it. As long as the TV still works and they have beer in the fridge and a gov’t check in the mail, they can’t be bothered and will contentedly poke fun at anyone says different.

    • the EMP producing explosion and other attacks like sabotage, internet interference and terrorism are the opening act …. the “real” attack follows …. if a man made type EMP event occurs – i’ll be the least of our immediate concerns as an average citizen – get your head down – FAST!!!!

      • Maybe … why waste millions of lives with an immediate invasion when they could just deny aid and wait for us to die off in huge numbers? Then they could waltz in when we are desperate and take over … quite possibly without firing a shot when we are good and desperate.

  • I see a few flaws here. If a serious EMP occurs from a nuclear generated source nothing will work – including broadcasting stations – at least for awhile, unless they were protected by a Faraday Cage. Simply shutting down and collapsing the electric grid can be severe enough without an EMP. The infrastructure is already so bad I imagine terrorists would do the job on the ground.

    • Max,

      Thanks for reading and commenting.

      It is true that in an NHEMP, most commercial broadcast stations would be put out of business and even hardened broadcast equipment would not work for several hours due to disturbance in the upper atmosphere, but within a day or so (if there were not any subsequent NHEMP’s) people will start transmitting on hardened equipment and pull regular equipment out of Faraday cages and begin broadcasting again. Picking up shortwave stations should be the best bet for the average person who does not own amateur radio equipment.

  • On another note, if your transistor type radio won’t work, or your car won’t start and the radio in your car won’t work, there’s your clue. I’d suggest, as a “Prepper”, look for the older tube-type radios available via “Vintage” websites, or garage sales, or ask around. It’s a good possibility that some of those are still around, you just have to find ’em. Also, make sure you have some way to power them. Batteries and an “Inverter” is one way. Or “Solar, or a “Generator”. Most of these “Tube-types” will require 110V AC and some foreign made may require 220V AC. Antique “Tube-types” most likely won’t fail you if an EMP happens.

    • Most modern generators have electronic parts like the engines ignition. All inverters are electronic. Unless these items were put into a cage previous to the EMP they too will be useless.

      • Not necessarily. If you can get an older, electro-mechanical vibrator type inverter, those should work. A company called ATR made a lot of them.

    • When were electronics introduced into radios? I bought at a garage sale an old kitchen radio that runs on 4 D batteries or electricity. It doesn’t have on On/Off switch, only Volume and station selector dials, and it has no FM band so I suspect it’s 1960’s vintage. Is it old enough it doesn’t need Faraday protection?

      Also, what about batteries? An article I came across recently said to wrap up batteries, too, but I haven’t seen that anywhere else.

  • The reason an enemy of the US would detonate a nuclear device to cause an EMP is to disrupt the US capability to defend itself. Sure it will cause chaos and possible civil disturbances but if you analyze what an EMP can do, it is highly possible that the defenses located in the area affected will be unusable for a long period of time. Missile defense, communications, vehicles, planes and ships may be affected. We may become “siting ducks” for an enemy attack. Do we trust our government to prepared and to have protection for their equipment? I sure don’t. The next election cycle from Nov 2015 to Jan 2016 is going to be very tempting to our enemies since the weakling is the white house may be on the way out and the new president may be a strong one. I’ll be in my bugout site during that period of time.

    • Most of our major military defenses can withstand at least one EMP hit. I used to work on some of those systems and I assure you our military units are not unprepared.

  • What people don’t seem to understand is that countries like Iran believe in the coming of the 12th Iman. Their Savior. But he will only come after they begin a major war. Then he will step forward a lead them to world domination. They are dead serious about this and our “leaders” have their heads squarely up their butts, as usual. So, for radical Muslims and many not so radical, “their goal” is to start a world war. Even North Korea exercises a level of common sense, but not these maniacs. So, I believe that the EMP weapon is ideal for their purposes for the United States and Israel. I also believe that thousand of them are here in the United States waiting for a signal. I you don’t believe that they are coming over our Mexican border every day by the hundreds, you are operating in a dreamworld with Obama. We now know that Al Quida is partnering with the drug cartels and have been for years. Lots of beheadings in Mexico recently.

  • I heard many years ago that EMP would only affect electronic devices if they were on. Have we forgot this? If something isn’t prducing a electrical field, why would EMP effect it? Then I see where EMP is knocking out mil ac out the sky and destroying our ability to respond. Does any one real believe all that hog wash? I was station at Nellis AFB in the early 80’s. Even the Secretaries computers were shielded so no signals got out to the Russian parked on the side of the road and no EMP would get in. We would spend millions on a weaponed systems that would be easily knock out. You want to know something about the military, ask someone in/was in the military. MAW, MSgt, Retire, USAF, 72-93.

    • Allen,

      While turning off devices would helpful for devices on the periphery, as much as 1,000,000 volts could be induced into any device with sufficient conductor length will, so subtracting 120-220 volts will not make much of a difference in most cases.

      Thanks for commenting and thanks for your service.

  • Where can we purchase non-conductive envelopes?

    • Non conductive envelopes can be purchased via electronics parts distributors, check Radio Shack etc. Another item I keep, is a CB radio and walkie talkies for such an incident, in an old unused (duh) microwave. They keep radiation from reaching you, why wouldn’t they shield it from getting in? Doesn’t even have to work, just fill it and shut the door. An old prepper mentioned that years ago, so I figure it’s worth a try! We’ll have to be innovative with power sources, solar being a big one, to power them, charge batteries, etc. Lots of planning involved if any of our ideas are going to be viable. Trying something is far better than doing nothing….

    • The paper ones you get at Wal Mart are non conductive. If you mean anti-static, those can sometimes be found at electronics stores. They may help a little, but they really don’t offer that much protection. Certainly no sub for a Faraday cage.

  • Why not just try your cell phone? Your cell phone has it’s own battery and most all cell towers have back up gen/batt. systems. If your cell phone does not work, EMP is a high probability.

    • That won’t tell you if it was a geomagnetic EMP or an HEMP. Your cell phone won’t see the tower in either event. If your phone is charging during the EMP, it would be fried in either a geomagnetic EMP or an HEMP.

      I had considered that, but it was too sketchy.

  • We need to always be prepared for the unexpected in any generation. Common sense is still essential in any situation. Always beware of your surroundings and stay cool !

  • I will have no problem telling when there is an EMP, as I have a spinal implant and it will fry when this happens. I will then be doomed to major pain for the rest of my life.

    • Donna,

      If you have TENS or similar device, it would be damaged by a HEMP, but not a geomagnetic EMP.

  • I remember reading about EMP weapons shortly after the first Gulf war. Essentially it was housed inside a bomb type case, no need for smart technology either.
    It consisted of batteries, a storage capacitor bank and an EMP generator.
    Upon being deployed the batteries began to charge the capacitors. As it dropped the charge built up and then once tripped the charge fed into the EMP generator.
    It was supposedly used in Bosnia and Kosovo

    • That is a non-nuclear EMP and has been developed into directed energy weapons like THAAD which is essentially a cruise missile capable of many discharges that can can fly around and blast targets with EMP. In it’s first test, they were unable to properly shield cameras documenting the test and they cut out. Good example of difficult EM shielding is if the military rocket scientists can’t shield against their own weapon.

  • Intresting read. Please send me other

  • I went to 3 different websites and read about using the 3 radios to determine if an emp had gone off. Your site was the only one to explain in detail the different results. Thank you.

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