Electromagnetic Pulse: A National Conference

Like the Proverbial Ostrich with its head in a hole in the ground...

Face it!!! It`s for REAL and this nation is more then vulnerable, it`s basically naive that it cars will start and a thunderstorm is NOTHING compared to a 5 megaton atmospheric burst...Russians have been using tubes for decades in anticipation of an event such as nuclear EMP strike... I had my car knocked out by a near miss of lightning, had to replace the chip and some other gadget plus 2 radios so you think it can`t happen??? Ha, wake up...
~!nuff said...

 

In a worst case scenario, it's possible to fly your typical light aircraft with no electrical power at all. Light aircraft tend to be entirely mechanical where it counts: even the flight instruments are air powered (or at least the backups are.) The ignition on piston engines is actually powered by a magneto, just like your lawnmower. Turbine engines also don't need much in the way of fancy electronics; there's only one control: a single valve to adjust the fuel flow.

Of course, light planes are a little different than large jetliners... but something tells me that with all the work the FAA requires manufacturers to do on redundancy, that there are ways for the pilots to control the planes even with the electronics down...

Of course, the French-made Airbus aircraft use fly by wire. Those would be helpless if they had a 100% power failure. I sincerely hope that their electrical systems are hardened.

 

I took an EMP protection course at Boeing, Worked on Minuteman missiles (well EMP hardened, BTW) and taught Radiological Defense through our State EM Office. The risk of EMP damage to electronics is real but nowhere near as great as some folks would have you believe. (Planes will not fall out of the sky and the Internet will not disappear in a puff of smoke.) And for those who are convinced an EMP attack is likely, the measures to provide protection are simple and inexpensive. FEMA CPG 2-17 "ElectroMagnetic Pulse Protection Guidance" has a wealth of information, as does the National Communications System's "Electromagnetic Pules/Transient Threat Testing of Protection Devices for Amateur/Military Affiliate Radio System Equipment" (NCS TIB 85-10). The Project Officer for this was Dr. Dennis Bodson, W3DZK, and various ham HF and VHF radios were tested. Bottom line: EMP damage is not a problem if you employ either simple protective devices or just disconnect the antenna and power cord.

 

A few thoughts I have had on this subject...

The military doctrine that sees an EMP as a first-strike weapon may be incorrect for a terrorist attack. If they don't have a follow-on force, what would be the point? I would expect that a terrorist attack that was going to use an EMP would first involve many lower-level attacks scattered around the country to draw out the EMS guys and get their gear into use, and thus more exposed. Only then would they "pop" their one or few nukes to try to fry the radios that are turned on and being used to deal with the first string of attacks. This scenario has the effect of "amplifying" the damage of the first attacks by hampering recovery efforts.

Regarding surge supression, I would suggest a 230V GDT in parallel with a 200V MOV. The MOV will fire on the rising edge, but only clamp to a voltage above the turn-on voltage of the GDT (note the tolerances on both devices in your favorite datasheet). This will allow the more-rugged GDT to handle the bulk of the surge, including the low frequency components that nobody seems to be talking about. I also like the idea of ferrite loading every conductor that is possible to access. It might not have a huge effect, but ferrites are cheap and it won't hurt.

Regarding delivery vehicles, if we are talking about a scud launched from a barge, then the EMP is going to have a limited radius and not cover the entire country due to line-or-sight effects. The east and west coasts are most vulnerable to this scenario. To cover the whole country with one burst would require the detonation to be over Kansas and at something like 300 mile altitude. If they could smuggle a scud into Kansas, launch it, and detonate at apogee, then maybe it could work, but the "smuggling a scud into Kansas" part might be difficult.

 

Bodson's paper appeared in QST in four parts ( links in an earlier post). One of our problems is that electronics has gotten a LOT more vulnerable since 1986. I am on the ESD committee where I work (for my sins; I complained about it) and we are now facing the prospect of devices that can be destroyed with only 20V of ESD. Susceptibility to RF is similarly worsened.

Add to that plastics and carbon composites and you get to a point where immunity must be increased many times over what was necessary just a few years ago -- if advanced technologies are to be used.

And they do; no one makes money selling TTL any more.

It is also not an exaggeration to say that these days, protective devices themselves often require protection.


Cortland
KA5S

 

WOOOOOOO, SCAREY!

Bitter Sarcasm On:

Be scared, American Bed-wetters, be very scared! And, don't forget to vote against your own best interest.

One question though:

Is this QRZ or World Net Daily?

If an EMP does go off over the US you may be sure that Pogo was right. We will have met the enemy and he will be us..., or he will be the Neocon - Israeli axis, who are us. I.E. Is this, like 9/11, the next PNAC, "Pearl Harbor Like Event" that will Galvanize the American public.

Ever So Sincerely,
Mikey
de AE4FB

Bitter Sarcasm Off:

 

EMP's

I am a retired physicist/ electrical engineer, and my master thesis in college
was on electromagnetic energy of Earth. Science knows that a nuclear explosion would cause some type of EMP event, however they don't know what would exactly be the final result of this event. Now it has been said that lightning is simular, to the power of an EMP. Well it is not, lightning is caused by friction and is an electostatic force, and EMP is electromagnetic pulse. The two are entirely different. The EM pulse is a wall of energy that passes over everything and generates a large amount of current for a very short period of time. Even though it is short period it will burn out most electronic devices because most electronic devices use current devices instead of voltage devices like the old tubes. Example: Attach a wire across you test leads of a volt ohm meter and pass a magnet across the wire. You will get a slight deflection on the meter. Now remember our country is covered with thousands of mile of wire for our power system. When an EM pulse hits the lines it generate a very
large current into the wire, thus burning out transformer and other power grid equipment.
In summary, we really don't know what will happen, but the possibilites are
real enough that we should not treat the possibility lightly.

 

Part 2 of the serialized report in QST (see page 39 QST, October 1986) tells us we can expect EMP power transients up to about 6 KV. Because the wiring will arc and protect against anything higher!

Shortly after arriving in Petaluma in 1997, I was in a motel when the power went out. I found my way to the front desk, where an irate customer was wanting his video game replaced. A car hitting a pole had dropped 100KV lines onto the 14 KV going down the road.

Seems to me, 6 KV could be enough.


Cortland
KA5S

 

This whole EMP thing is blown way out of proportion. An EMP blast (1 megaton at 40 miles altitude) at 20 miles is no more significant than a lighting strike at 1000 feet.

The pulse width due to the explosion time is 10X-8second. This places most of the RF energy pulse at somewhere around 100 MHz. The Plasma oscillations have a peak at about 10 KHz and last much longer up to 30 minuets. At 10 KHz you can see the effect on power lines would be much more extreme than HF-UHF communication due to wavelength of 10 KHz. A 10 KHz half wavelength is about 8.8 miles.

The largest problem with high altitude burst is the plasma heat will disrupt the electrons in the ionosphere. This in affect will shut down HF DX operations for many days and depending on altitude for up to a week. At a burst height of 40 miles the effects on HF communication can last up to 10 hours before any communications is possible.

The above information is from the” Effects of Nuclear Weapons” revised for the Air Force in 1964 published in 1952.

By 1957 so many tests had been run on airburst and ground burst that not much was left to know about atomic explosions. Jack Ass Flats in Nevada exploded over 600 above ground test before they were banned in 1962.

Now this is only a suggestion but if you are in the range of an atomic weapon airburst do not get on the air. You have more important priorities.

 

I forgot to add a lightning strike is a burst of discharge energy just like an EMP pulse. The voltage build up may be molecule friction in the cloud but so is an atomic explosion. Instead of molecules causing the friction it is atomic particles.

A lightning strike lasts about 8 uS for 80% of the energy with a decay of up to 20 uS. Most lightning strikes have several of these pulses until the ionization path is lost from cloud to cloud and cloud to ground paths.

Electronic pulse intensity falls off by the square of the distance. Double the distance and the intensity is ¼ of the reference level. This is true for all radiation from sound to gamma rays.

Only Russia, France, China, Great Britton, Israel and South Africa are capable of a real air burst above 40 miles in altitude. All have a great desire to live and as a result are not a problem. Rouge states that worship death is another problem. The ability to make an atomic weapon is not as difficult as the delivery system.

 

EMP is a Fraud!

Just like I was taught in the Army. If you are close enough to a Atomic or Nuclear blast to witness the effects of EMP it will be a last concern on a list of more basic priorities. Such as kissing your butt goodbye!!!!

Who is trying to spread this Propaganda? Who is it that has something to gain from scaring the general public into believing this? Someone somewhere just like AL GORE with his Global Warming has some type of monetary gain involved in this. If there wasn't money to be made from this it wouldn't even be a discussion I can promise you that!!!!

But these type of ignorant people runnign around is why this Country is in the shape it's in today!

DE WW5RM

Randall

 

OK... But you seem to be the only one in this discussion that thinks this can NOT be a problem. After reading most of these posts, I feel a wee bit better about it all though.

Global warming is real too, but we may not be able to do anything about that, either.

boB

 

Y'all realize there's such a thing as NON-nuclear EMP weapons right?

Just saying.. it doesn't have to be a high altitude air burst, just a specially built bomb: http://superconductors.org/emp-bomb.htm