As I’ve mentioned in past articles, I believe taking some precautions against EMPs is important. While I feel that an intentional nuclear EMP is unlikely, our local star can cause even more damage to an even larger portion of our planet if it decides to cause a solar storm like the Carrington Event.
Every so often, our star fires off a plasma bomb in a random direction. Our best hope the next time Earth is in the crosshairs? Capacitors.
TO A PHOTON, the sun is like a crowded nightclub. It’s 27 million degrees inside and packed with excited bodies—helium atoms fusing, nuclei colliding, positrons sneaking off with neutrinos. When the photon heads for the exit, the journey there will take, on average, 100,000 years. (There’s no quick way to jostle past 10 septillion dancers, even if you do move at the speed of light.) Once at the surface, the photon might set off solo into the night. Or, if it emerges in the wrong place at the wrong time, it might find itself stuck inside a coronal mass ejection, a mob of charged particles with the power to upend civilizations.
The cause of the ruckus is the sun’s magnetic field. Generated by the churning of particles in the core, it originates as a series of orderly north-to-south lines. But different latitudes on the molten star rotate at different rates—36 days at the poles, and only 25 days at the equator. Very quickly, those lines stretch and tangle, forming magnetic knots that can puncture the surface and trap matter beneath them. From afar, the resulting patches appear dark. They’re known as sunspots. Typically, the trapped matter cools, condenses into plasma clouds, and falls back to the surface in a fiery coronal rain. Sometimes, though, the knots untangle spontaneously, violently. The sunspot turns into the muzzle of a gun: Photons flare in every direction, and a slug of magnetized plasma fires outward like a bullet.
The sun has played this game of Russian roulette with the solar system for billions of years, sometimes shooting off several coronal mass ejections in a day. Most come nowhere near Earth. It would take centuries of human observation before someone could stare down the barrel while it happened. At 11:18 am on September 1, 1859, Richard Carrington, a 33-year-old brewery owner and amateur astronomer, was in his private observatory, sketching sunspots—an important but mundane act of record-keeping. That moment, the spots erupted into a blinding beam of light. Carrington sprinted off in search of a witness. When he returned, a minute later, the image had already gone back to normal. Carrington spent that afternoon trying to make sense of the aberration. Had his lens caught a stray reflection? Had an undiscovered comet or planet passed between his telescope and the star? While he stewed, a plasma bomb silently barreled toward Earth at several million miles per hour. [Continue reading at Wired…]
The following article is an original work published by the Information Professionals Association. Opinions expressed by authors are their own, and do not necessarily reflect the views of or endorsement by the Information Professionals Association.
By Tom Kent
As Vladimir Putin tightens his stranglehold on what his citizens see and hear, will radio once again become an effective way to get outside voices into Russia?
For the time being, U.S. broadcasting officials believe the best way to get their content to Russia’s population is still through the internet, despite all of Putin’s attempts to control it. Activists in the United States and Europe, however, are convinced that in a wartime situation, those wanting to reach Russians should be trying everything – including shortwave radio, the mainstay of Cold War broadcasting by the Voice of America (VOA) and Radio Free Europe/Radio Liberty (RFE/RL).
The U.S. government’s reluctance to return to shortwave has led to the odd spectacle of American volunteers taking broadcasting into their own hands. Activists have crowdfunded projects to transmit on shortwave channels programs produced by VOA and RFE/RL that the government declines to broadcast with its own transmitters.
Shortwave broadcasting uses high frequencies that can reach across continents. During Soviet rule, VOA, RFE/RL, the British Broadcasting Corporation (BBC) and other stations used shortwave to punch news, religious programs and forbidden Western music through the Iron Curtain. Soviet jamming stations tried to drown out the broadcasts, but much of the content got through.
With the collapse of the Soviet Union and the rise of the internet in Russia, foreign shortwave broadcasting tapered off. Boris Yeltsin let RFE/RL open local stations in some 30 Russian cities, but under Putin they were forced to close because of Russian laws. The United States then switched its radio and video services for Russians almost entirely to the web and social networks.
Since the war began, however, Russian authorities have increasingly blocked from the internet any content that criticizes the war or Putin’s rule. Many Russians use VPNs and other software to get around the blocks, and have come to the US broadcasters’ websites and social network feeds in droves. But Russian officials are working feverishly to block these circumvention tools, and may be able to determine which citizens are using them. [Continue reading on the IPA website…]
With music consumption having long ago moved to a streaming model in many parts of the world, it sometimes feels as though, just like the rotary telephone dial, kids might not even know what a radio was, let alone own one. But there was a time when broadcasting pop music over the airwaves was a deeply subversive activity for Europeans at least, as the lumbering state monopoly broadcasters were challenged by illegal pirate stations carrying the cutting edge music they had failed to provide. [Ringway Manchester] has the story of one such pirate station which broadcast across the city for a few years in the 1970s, and it’s a fascinating tale indeed.
It takes the form of a series of six videos, the first of which we’ve embedded below the break. The next installment is placed as an embedded link at the end of each video, and it’s worth sitting down for the full set.
The action starts in early 1973 when a group of young radio enthusiast friends, left without access to a station of their taste by Government crackdowns on ship-based pirate stations, decided to try their hand with a land-based alternative. Called Radio Aquarius, it would broadcast on and off both the medium wave (or AM) and the FM broadcast bands over the next couple of years. Its story is one of improvised transmitters powered by car batteries broadcasting from hilltops, woodland, derelict houses, and even a Cold War nuclear bunker, and develops into a cat-and-mouse game between the youths and the local post office agency tasked with policing the spectrum. Finally having been caught once too many times, they disband Radio Aquarius and go on to careers in the radio business.
The tale has some tech, some social history, and plenty of excitement, but the surprise is in how innocent it all seems compared to the much more aggressively commercial pirate stations that would be a feature of later decades. We’d have listened, had we been there!
Many thanks to SWLing Post contributor, David Shannon, who shares a link to a transcript on the UK Parliament website and notes that “it’s not often” the topic of CMEs comes up in the House of Commons. (We have discussed them here, of course.)
It is a pleasure to rise for my first Adjournment debate in many years—once a decade perhaps.
I am a little concerned that people might think that I am trying to be the new Lembit Öpik of this Parliament, in that he was famously obsessed with asteroid impacts that never occurred. Equally, people might think I have been spending far too much time during lockdown watching boxsets, such as “Cobra” on Sky Atlantic, which I was wholly unaware of until I watched an episode this weekend. I assure the House that it had no impact at all on me picking this particular topic.
People might wonder what on earth I am on about. What is a solar flare? A solar flare, also known as space weather or coronal mass ejection, is an event that has the potential to knock out our electricity grid by causing voltage instability, power transmission network instabilities and transformer burnouts. A modest one in Quebec in 1989 did just that for a few hours to the Hydro Québec grid.
A bigger solar flare is likely to be around the corner, even if we do not know when. The last so-called biggie was in 1859, called the Carrington event. That was a very different era, with fewer consequences. Events with limited impacts have occurred throughout the past 100 years, but as we become more reliant on technology, they have an impact on navigation systems, aviation and satellites, increasingly. As with Los Angeles atop the San Andreas fault, another episode is both expected and unavoidable.
It is important to prepare, and with the knowledge that we will have very little warning that such a solar flare is occurring before we suffer the consequences. Government say that we are the best prepared in the world but, without being unkind to them at the moment, those are the precise words used of our pandemic preparations. It is therefore worth exploring in greater detail whether we are truly prepared for any solar flare, let alone the right sort of solar flare. The concern in the UK is that, while there was some pandemic preparation, it was for the wrong sort of virus.
The Civil Contingencies Unit might be able to maintain the national strategic stockpile of body bags. The NHS might well have tried to foresee every strain of virus, and ensure that vaccines were available, but the collision of plans with reality is always the point at which flaws are revealed. I do not mean that we should be looking at websites for survivalists and preppers, or stocking up on tinned food—we have had enough panic buying this year. However, we should consider those risks that the scientific community believes to be worth mitigating.
It is fair to ask how far the Government have progressed since the 2015 space weather preparedness strategy. As good as it is to know that solar flares are on someone’s radar somewhere in Whitehall, some of its relaxed conclusions may need re-testing. For example, the document rather blithely states:
“Some of this resilience is not the result of planning for this risk but good fortune.”
It gives me slight pause for thought that we are relying on good fortune to see us through future space weather. ?
To me, the golden thread stretches from the Met Office alerting the Government to the imminence of a solar flare, to the National Grid then having a limited period of time—if any—to implement mitigating measures.
The hon. Gentleman’s coastal region has the potential to suffer the same problems from solar flares as my coastal region, and I am pleased that he has brought this forward for the House’s consideration. Is he aware that coastal and more rural areas like both of ours would be worst hit? We need to ensure that we are not left languishing, waiting for replacement transformers. Does he further agree that planning should include specifics for coastal areas in particular?
I was fascinated to see how the hon. Gentleman would respond to the challenge of this topic in an Adjournment debate and he has surpassed my expectations. I urge him to speak to EirGrid, which is the grid that covers Ireland. I am sure it will be interested in explaining to him what actions it is taking. But there are issues we have to consider. The 2015 space weather preparedness strategy indicates that the nearest radiation monitor to the UK is in Belgium. Can the Minister confirm whether that remains the case, and whether our decision to pull out of all EU agencies in any way jeopardises our access? Either way, what steps have been taken to develop sovereign capability in that regard? When was the last Met Office review of warning systems for space weather, and what role would he anticipate for the UK Space Agency?
The British Geological Survey has three operational magnetic observatories. Can the Minister confirm that that remains the case, and explain how resilient they are in and of themselves to space weather? The 2015 review described a number of priorities for future investment. Can the Minister update the House on what publicly funded research has now commenced on space weather, as per the strategy? Can he update me further on what progress has been made in working with international partners?
The Government’s 2015 report stated
“the GB power grid network is highly meshed and has a great deal of built in redundancy. This potentially makes it less susceptible to space weather effects than power grids in some other countries. Over recent years a more resilient design for new transformers has been used to provide further mitigation.”
That is all very positive, you might think, but a 2013 report by the Royal Academy of Engineering painted a slightly different picture:
“Since the last peak of the solar cycle, the Great Britain transmission system has developed to become more meshed and more heavily loaded. It now has a greater dependence on reactive compensation equipment such as static variable compensators and mechanically switched capacitors for ensuring robust voltage control. Thus there is increased probability of severe geomagnetic storms affecting transmission equipment critical to robust operation of the system.”
That is a little less positive.
Right now, National Grid seems to be focusing on hanging on to its role as the electricity system operator, as well as balancing expanding offshore wind farms and building interconnectors to them. Does it have the bandwidth that it needs to keep checking whether its network of transformers can withstand an event of space weather? Back in 2015, it calculated that some ?13 transformers were at risk, and the likes of the US are stockpiling back-up transformers. National Grid is supposed to have spare transformers, but it is not clear how many. If we were to need more, do we even have the industrial capacity to build them, notwithstanding the eight to 12-week lead-in time, and the need to transport them by road to their destination? What more can Government do to assist increasingly commercially oriented companies such as National Grid in this regard, and what progress has been made on developing transportable recovery transformers, as was suggested as far back as 2013? What progress does the Minister believe National Grid is making on installing such mitigating inventions as series capacitors and neutral current blocking devices? Interconnectors are a good thing in themselves. They are also direct current equipment, and as such are not affected. However, during a solar flare, they may be affected, because the convertors to alternating current at either end will come under risk. As we develop ever more interconnectors, what steps is the Department for Business, Energy and Industrial Strategy taking to ensure that those new interconnectors are made as resilient as they can be? Crucially, can I ask when the last national risk assessment update was conducted by the Government?
Some dangers never come to pass—Y2K passed without incident—but just occasionally, I believe it is worth posing the question “What if?” and not just trusting that it will all be fine, because that is the answer we want to hear and the alternative is perhaps far too unpalatable. Covid-19 teaches us many lessons about preparing for worst-case scenarios, and making sure that we assess all possible outcomes must surely be one of the key lessons that we learn. I look forward to learning what the Minister has to say.
I was very interested to hear the speech by my hon. Friend the Member for Blackpool North and Cleveleys (Paul Maynard). He mentioned solar flares, and the fact that in the 19th century, people were very conscious of those solar flares. I would like to remind him, as I am sure he knows, that a whole economic theory about the business cycle relating to solar activity was presented in the 19th century, and there are British economists who are very interested in this subject. As a country generally, we have been very interested in solar activity, so I thank him for raising a subject that is very important. It is not as abstruse or obscure as people might think: the question we are considering is a very serious one.
Those severe space weather events are rare, but when they do occur, they can have a big impact on national infrastructure, as my hon. Friend has suggested. As such, it is—I am sure he will be pleased to hear this—a risk that we take very seriously. Severe space weather was first recognised as a risk in our 2011 national security risk assessment, and the 2017 national risk register of civil emergencies provided the most recent assessment of the likelihood and potential impacts of that risk. This assessment is kept under constant review: it is not something that we simply put away in a drawer once it was written up.
Of course, predicting when severe space weather events can happen is crucial to minimising their impact. I am pleased to reassure my hon. Friend that the UK is a ?world leader in this area, as I suggested in my earlier remarks. The Met Office’s Space Weather Operations Centre is one of only three 24/7 forecasting facilities in the entire world. Its systems are kept under constant review, and we are constantly looking to improve how we can maximise our capacity in this area. In recognition of the importance of these forecasts and the ability to conduct forecasting, in 2019 the Prime Minister announced a £20 million boost for research in this area, which represented a near quadrupling of the amount that we were spending. This funding means that the Met Office will be able to improve both the accuracy of forecasts and its warnings.
I have to say that when my hon. Friend mentioned the three operational magnetic observatories, I was very interested. I did actually do some preparation on that topic, and I am very pleased to say that all three magnetic observatories are operational. They are situated in Shetland, on the Scottish borders and in north Devon, and they greatly enhance our capabilities in this area. They are also extremely resilient to space weather.
My hon. Friend mentioned National Grid. The whole issue of National Grid ESO and National Grid’s relationship to it is something that again is under constant review. It is the subject of some debate in the industry. However that question is answered, I can reassure him that we have a resilient energy system. I was struck by the fact that he mentioned a report from 2013. He and I have been in the House of Commons since 2010, I think, and I hope he does not take it amiss if I say that 2013—certainly in the context of energy—is a very long time ago. We have had a huge increase in the deployment of offshore wind and we have more interconnector capacity. I suggest to him that the capacity and resilience of the system is considerably greater than was the case in 2013. Having said all that, I accept that the risk is serious, and he rightly draws it to my attention. I will take the matter up directly with National Grid and the ESO.
As far as National Grid and the ESO are concerned, they feel that they have instigated a few mitigating measures, including increasing the number of spare transformers so that damaged equipment can be replaced quickly. We have been assured—I can revert to my hon. Friend on this—that there are sufficient spare parts to deal with the reasonable worst-case scenario, and there are plans to deploy this spare capacity. Also, critically, we have to introduce—and they are introducing—a new design of transformers, which will be far more resistant to the effects of space weather that he described.
With respect to interconnectors, my hon. Friend will know that it is a direct current but the transformers transform it to alternating current, and that is an area again where we think we can get added protection from the risks he outlined. We will publish a new space weather strategy next year, which will set out a five-year road map—a five-year vision—for how we intend to boost resilience and build on existing UK strength and capacity in this area. It will also provide what he has asked for: an update on the progress that we have achieved since the 2015 strategy was published.
The long history of close working among the energy industry, thinkers and leaders of thought in the sector and the Government means that we have a good understanding of the risk posed by solar flares to ?the electricity network. We think we have put in place proportionate measures that will mitigate those risks, and I am firmly of the view that the system is highly resilient, but, once again, I am extremely open to ideas from my hon. Friend and from Members across the House—from all quarters—as to how we can improve our resilience and our ability to forecast potential danger in this area.?
I once again thank my hon. Friend for raising this issue. Far from being a flippant or trivial subject for an Adjournment debate, it is my pleasure to respond on a very serious problem. I hope we can assure him that the problem is well scoped and that we have decent mitigations in place.
Question put and agreed to.
Thanks for the tip, David. It’s my impression that many power grids across the planet are being upgraded to better handle potential destructive EMPs. Of course, this is an investment into upgrades we hope we never need, thus local/national governments don’t always take the threat seriously.
On Sept. 1st, 1859, the most ferocious solar storm in recorded history engulfed our planet. It was “the Carrington Event,” named after British scientist Richard Carrington, who witnessed the flare that started it. The storm rocked Earth’s magnetic field, sparked auroras over Cuba, the Bahamas and Hawaii, set fire to telegraph stations, and wrote itself into history books as the Biggest. Solar. Storm. Ever.
But, sometimes, what you read in history books is wrong.
“The Carrington Event was not unique,” says Hisashi Hayakawa of Japan’s Nagoya University, whose recent study of solar storms has uncovered other events of comparable intensity. “While the Carrington Event has long been considered a once-in-a-century catastrophe, historical observations warn us that this may be something that occurs much more frequently.”
To generations of space weather forecasters who learned in school that the Carrington Event was one of a kind, these are unsettling thoughts. Modern technology is far more vulnerable to solar storms than 19th-century telegraphs. Think about GPS, the internet, and transcontinental power grids that can carry geomagnetic storm surges from coast to coast in a matter of minutes. A modern-day Carrington Event could cause widespread power outages along with disruptions to navigation, air travel, banking, and all forms of digital communication.
Many previous studies of solar superstorms leaned heavily on Western Hemisphere accounts, omitting data from the Eastern Hemisphere. This skewed perceptions of the Carrington Event, highlighting its importance while causing other superstorms to be overlooked.
[…]Hayakawa’s team has delved into the history of other storms as well, examining Japanese diaries, Chinese and Korean government records, archives of the Russian Central Observatory, and log-books from ships at sea–all helping to form a more complete picture of events.
They found that superstorms in February 1872 and May 1921 were also comparable to the Carrington Event, with similar magnetic amplitudes and widespread auroras. Two more storms are nipping at Carrington’s heels: The Quebec Blackout of March 13, 1989, and an unnamed storm on Sept. 25, 1909, were only a factor of ~2 less intense. (Check Table 1 of Hayakawa et al’s 2019 paper for details.)
“This is likely happening much more often than previously thought,” says Hayakawa.
Are we overdue for another Carrington Event? Maybe. In fact, we might have just missed one.
In July 2012, NASA and European spacecraft watched an extreme solar storm erupt from the sun and narrowly miss Earth. “If it had hit, we would still be picking up the pieces,” announced Daniel Baker of the University of Colorado at a NOAA Space Weather Workshop 2 years later. “It might have been stronger than the Carrington Event itself.”
With the way 2020 has gone so far, it might be wise to take a look at our EMP Primer which goes into detail about how to protect your radio gear from an EMP event like this. It’s not an expensive process, but requires advance preparation.
Each year at the Dayton Hamvention I enjoy checking out the latest radio products and services. This year (2019) I found an exceptional number of innovations and will share these in Hamvention Highlights posts. If you would like to check out 2019 Hamvention Highlights as I publish them, bookmark this tag: 2019 Hamvention Highlights
At the 2013 Dayton Hamvention, Palstar showcased a prototype HF transceiver called the TR-30. I posted a note about this at the time on my ham radio blog, QRPer.com. The TR-30 never seemed to make it to the market, but that’s not surprising considering the Elecraft KX3 and a number of other QRP transceivers were released the following year.
This year when I approached the Palstar booth, I found a new prototype transceiver: the Palstar TR-30A EMP.
This TR-30 iteration will, without a doubt, have a unique place in the radio market since it has been designed to withstand electromagnetic pulses (EMPs). To be clear, I know of no other transceivers on the ham radio market that are EMP hardened.
The Palstar TR-30A EMP requires no external EMP shielding or special handling/storage. It will be natively EMP-proof, even while hooked up to an antenna and without an RF ground attached.
I spoke with Paul Hrivnak (N8PH), President and CEO of Palstar, at Hamvention and he shared a few details about the Palstar TR-30A EMP:
The transceiver will be general coverage and will be able to operate on all of the HF ham radio bands.
It will have a very simple set of functions–at this point, he doesn’t even plan to have dual VFOs.
The output power will be 20 watts.
The front panel controls will be very simple and intuitive.
The TR-30A EMP’s unique internal antenna tuner will–if I understand it correctly–be able to match pretty much any load. It will have manual controls, but will be digitally controlled. Paul said that the ATU is being designed so that a satisfactory match can be found for any make-shift field antenna. I can’t wait to check it out for myself because I hold Palstar in high regard when it comes to antenna tuners.
Of course, from the ground up, the TR-30A EMP will be hardened against EMPs.
He hopes the Palstar TR-30A EMP will be in production by the end of 2019 and retail for $1,100 – 1,200 US.
Of course, I will post any news and updates about the Palstar TR-30A EMP here on the SWLing Post. I will also plan to review and evaluate the transceiver when it hits the market.
Records kept by people living in Korea, China and Japan in 1770 have revealed evidence for the longest geomagnetic storm in recorded history
Almost 250 years ago, for over two weeks, the skies above parts of Asia lit up in what looked like a burst of fiery red. Those who saw the strange phenomenon kept notes of the event, and now it has been identified as potentially the longest geomagnetic storm ever recorded.
A dim red sky reported to have been observed between the September 16 to 18, 1770 in East Asia was considered one of history’s greatest geomagnetic storms. But now, new materials have come to light suggesting the storm lasted much longer, for nine nights, and covered an area twice as large as originally thought.
A group of Japanese scientists led by Hisashi Hayakawa from Osaka University studied hundreds of historical records dating between September and October 1770, including government records and people’s personal diaries. Using these records, they were able to piece together what happened during the event, and link this to sunspot drawings from the time.[…]
Of course, I’ve read in-depth information about the Carrington Event, but was completely unaware of the 1770 event. I’ve always said the biggest EMP threat will come from our local star. Frankly, it’s just a matter of time. I hope we’re ready!
Will modern portable radios survive an EMP? Likely not without protection.
Here on the SWLing Post we tend to cover topics related to shortwave radio, ham radio and international broadcasting. We also cover an array of other topics our contributors and readers find appealing.
Lately, I’ve noticed an uptick in one particular question–at least, variations of it–from readers and people who found our site searching for emergency/preparedness radios:
“What radio can survive an EMP?”
“How could I protect a radio from an EMP?”
What is an EMP?
In case the term EMP is new to you, check out this explanation from Wikipedia:
An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy. Such a pulse’s origination may be a natural occurrence or man-made and can occur as a radiated, electric, or magnetic field or a conducted electric current, depending on the source.
EMP interference is generally disruptive or damaging to electronic equipment, and at higher energy levels a powerful EMP event such as a lightning strike can damage physical objects such as buildings and aircraft structures. The management of EMP effects is an important branch of electromagnetic compatibility (EMC) engineering.
Weapons have been developed to create the damaging effects of high-energy EMP. Misleading or incorrect information about such weapons, both real and fictional, have become known to the public by means of popular culture and some politicians’ claims. Misleading information includes both exaggeration of EMP effects and downplaying the significance of the EMP threat.
In short? A strategic EMP could cripple our electrical grid and potentially many other electronic and digital devices.
Most of us are concerned with wide-spread disruptions from electromagnetic pulses originating from:
Man-made atomic weapons
Natural occurrences, like solar flares/storms
A solar flare erupts on the far right side of the sun, in this image captured by NASA’s Solar Dynamics Observatory. (Image: NASA/SDO/Goddard Space)
As the Wikipedia article indicates, there’s a lot of confusing and misleading information out there regarding EMPs. And while some of this reportage underplays the seriousness of this very real, if rare, concern, a great deal of it, including the fiction about it, is more alarming than it needs to be.
So I turned to a good friend who happens to be an expert on EMPs.
My pal has worked for thirty-five years designing military radar equipment, broadcast transmitters, and automotive electronics.
His profession requires that he knows how to “harden” equipment against all types of EMP threats, and thus is regarded as a specialist in this field. Because of his professional ties he’s asked that I withhold his name.
My EMP expert friend is also very pragmatic. That’s why I asked him to explain how EMPs might affect us both generally and specifically, in terms of communications and the radio world.
I asked him to address what effects an EMP might have, both nuclear and solar originated, and how what practical preventative measures we might take to mitigate the damage to our radio equipment. His reply follows…
Anxiety over EMP seems to recur every time there is a change in the established order. The premise of Mutually Assured Destruction that has kept us ‘safe’ in the nuclear age vanishes when confronted by a suicidal adversary. That _seems_ to be the case at present.
So let’s look at the facts available:
A nuclear EMP has its peak energy in the 1 MHz range, with appreciable energy even in the 1 GHz range. It has field strengths of up to 50 kV/m.
The wiring inside of modern consumer electronics, including PCB traces, is close to GHz wavelengths, so they will be effective [in] receiving that energy and carrying it to any electronics [to which] it is connected.
There was a series of articles in QST 30 years ago by Dennis Bodson (W4PWF) that should be the go-to reference:
[Note: the following links require that you’re logged into the ARRL website and are a current member.]
The author related results of a number of tests on equipment by the US in EMP simulators.
The impact on vehicles
One observation was that vehicles were not affected.
As a former automotive engineer, I can attest to the lengths to which designers go to make automotive electronics resistant to damage. A vehicle must be designed to withstand operation with no battery, reverse battery voltage, inductive surges, and other abuse. Automotive electronics are designed to operate under radio and TV transmitters without damage.
There are of course anecdotal accounts of ham equipment causing vehicle computers to go haywire, but if (and that is a BIG IF) the equipment was designed properly, there will not be damage. One area where EMP will cause damage in a vehicle is the car radio. It is tied to an antenna that will conduct the surge directly into the very fragile receiver circuitry.
That said, the amount of electronics in a vehicle is hugely increased since these articles were written in 1986, and even after I left the automotive industry in 2006.
The specs for automotive EMI resistance have not changed in that time, though.
The way that you keep EMP out of any object is to surround it in conductive metal, so that no gaps exist. Think of a microwave oven that must keep the radiation _in_. The screen in the door window has tiny holes you can see through, but much smaller than the wavelength of the oven. Where microwave leaks are most likely to occur is around the door, where the metal shield is not continuous.
If you want to shield electronics from EMP, the coverage by the metal shield must be continuous. A gap or slit will permit the energy to penetrate.
Sample of reclosable ESD bags.
In the silvered plastic Electrostatic discharge (ESD) bags that are very popular for EMP protection, the zip-lock seam is the weak point in the shielding. You can very easily just use two bags, one inside the other, with the seams in opposite directions, to make a greatly improved shield.
Aluminum foil is a great shielding medium, [and] it’s cheap and plentiful.
Use a big piece, and wrap several overlapping layers. It’s hard to do better.
Many of the solutions used for EMI and RFI lose their effectiveness in the high field strengths of an EMP.
The ferrite snap-on chokes saturate at high magnetic field intensities, and lose their permeability, and the ability to stand off conducted surges.
Use of ammo boxes or file cabinets for EMP protection [a popular method promoted by many on the Internet] is of limited effectiveness because of the large gaps between sheets of metal, and the poor conductivity of steel.
A galvanized trash can is a better solution, because of the conductivity of the zinc galvanization.
The gap around the lid should be covered with adhesive copper tape, available at craft and garden supply stores.
Batteries are not affected by EMP. But a battery pack with a built in smart charger may be.
Be aware that LiFePo batteries tend to have built-in smart charge controllers.
Store battery packs safely shielded also––but make sure the terminals cannot contact the metallic shield and cause a short!
Tube/Valve radio equipment
Vintage tube radios will likely survive an EMP, but how do you power them without mains electricity? By modern standards, valve gear is power hungry!
Vacuum tube equipment is very resistant to EMP, as [it] can withstand arcing and surges with no damage.
The bigger question is, how do you power it afterward?
Suppress Surges and Unplug
Much of the damage from an EMP will be conducted, coming in on power lines. Always unplug any critical electronics when not in use. Also, put a surge suppressor on every outlet [into which] you have electronics plugged.
It is cheap insurance. Even of you are not in line-of-sight of an EMP, the conducted surge can wipe out costly appliances. I do this as protection anyway because of my ham antenna. When lightning hit the tree outside my house ten years ago, we only lost two CFL bulbs, while every neighbor on our block lost TVs, microwaves, and washing machines.
Gamma Ray Bursts
EMP radiation should be distinguished from ionizing nuclear radiation. Exposure to a gamma ray burst from near proximity to a nuclear event will disrupt electronics also, but that is an entirely separate topic.
Most Important Communication Medium During Disasters
(Hopping on soap box) The most important form of communication is that which covers the shortest distance. Get to know your neighbors. When bad things happen, they will be the people who will help you out, and be the most grateful when you help them. We’re seeing this happen on a massive scale in Houston [Florida and Puerto Rico] right now. (off soap box).
The subject of EMP is very controversial. There is a tremendous amount of misinformation out there. There is disagreement even among the experts.
The problem is that since aboveground nuclear testing…ended a generation ago, there is very little relevant information existing, since semiconductor electronics were in their infancy at that time this occurred. Most information that there is has come from EMP simulators, which are assumed to create waveforms close to that of a nuke. We all know…how risky assumptions can be!
But we do know how to make shielding, and we do know what kind of effects will damage electronics, and we can use this knowledge to try to assure that the preparations we make will be sufficient to protect our electronics.
All of these are very hostile EMI/EMC environments, and the specifications for their design are very strict. These designs offer guidance as to how to create EMP resistant electronics. What are offered are opinions, but hopefully well informed opinions. If I’m wrong, I won’t argue about it, there is more at stake than ego.
Answering common questions
Many thanks for these useful insights and explanations. And now, with all of this in mind, let’s re-evaluate questions about EMPs and radios:
“I understand tube/valve radios can survive an EMP. Which model should I buy?”
My answer: You’re correct; as discussed above, vacuum tube equipment is very resistant to EMP, as it can withstand arcing and surges with no damage.
However…without mains power (the most likely result from a strategic EMP) how will you power tube gear––? Many tube radios were never designed to be operated from a battery source. Those that could, require batteries with a fairly exceptional amount of capacity. Vacuum tube radios are not efficient compared with modern solid-state battery-powered radios.
If you have an generator or power source that is hardened to survive an EMP, and you have a plentiful supply of fuel to run it, then you may consider a tube radio. Otherwise––or better yet, additionally––protect a much more efficient portable radio.
“What radio can survive an EMP?”
Any radio that is properly shielded from the effects of EMP should survive an EMP.
“How can I protect a radio or other portable electronics from an EMP?”
After you’ve chosen which radio to protect, take the extra precaution of removing any attached telescopic antenna. Most antennas are held in place with a simple tiny stainless steel screw/bolt. Unscrew it, pull the antenna off, place both pieces in a small bag and keep it with the radio.
Next, place the radio in a container that will act as a “Faraday cage” to exclude an EMP’s electrostatic and electromagnetic influences. There are a number of commercial products specifically designed for this use, but it’s more simple and affordable to adopt one of the procedures our expert outlines above. Let’s re-cap:
Find a bag that’s large enough to fit your radio; many of the bags designed for SATA hard drives should fit more compact radio models.
Place the radio (and its detached antenna) into the ESD bag and close the zip seam.
Then, place the ESD bag containing your radio equipment into another ESD bag, making sure the bag seams are on opposite ends.
Consider wrapping your radio or electronic device in its box. Not only does it insulate the contents, but it makes an easier surface to wrap in foil.
Wrap the radio in at least three layers of aluminum foil. Make sure all seams are tightly sealed with each layer of foil. Each layer should completely enclose and protect the radio.
I wrapped this radio in three layers of foil, carefully sealing seams on each layer.
Galvanized Trash Can
As mentioned above, items can be placed in a galvanized trash can for protections.
Simply line the inside of the can with a dielectric material (cardboard, thick cloth, foam, or something similar) so the contents cannot touch the sides, bottom, or lid of the can.
It may be overkill, but I might also wrap my electronics in aluminum foil before placing it inside, again making absolutely certain your equipment in its foil wrap is NOT touching the metal of the can. This would simply serve as a secondary–redundant–layer of protection.
If you live in a humid area, you might put some sort of moisture protection inside as well.
More to come…
In the final part of our primer, we’ll take a look at what sort of radios you should consider packing away for emergency use, discussing selection criteria.
I’ll link to this article once it’s published, so stay tuned for more on this intriguing subject. Follow the tag: EMP
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