Shock Wave Damage?

Well my guess is that in the event of a nuclear blast the loss of a radio will be the least of your worries however....

My limited understanding is that an EMP generates fields large enough to cause arcing in chain-link fence and similar metalic structures. At those levels descrete transistors won't be significantly more robust than microchips - everything will fry, possibly even the wire in the speaker, battery etc.

I did hear of a story that the Russian used valves in the radios of their fighter aircraft as an anti EMP measure - but I believe this to be untrue - I believe they used them because they didn't have suitable transistors at the time.

All semiconductors will be damaged from any EMP (Electro Magnetic Pulse), if it is strong enough. I would think that if you were in an area that had an EMP strong enough to damage any type of electronic apparatus, you would not have to worry about it for eternity!

Testing found that the tube type circuits are more robust for EMP exposure, but if the EMP is strong enough, they will also be damaged. If it is intense enough even the wiring, and a some metal parts will also melt, or burn up.

I am curious... What brought this type of question up???

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Greetings,

Jerry Greenberg ===========

69 miles away, so I got an FM antenna and put it up. However I needed a receiver with an external antenna connection. I found an old Pioneer tuner at a second hand shop, but when I got home I realized it needed an amplifier. I took an old portable radio apart and connected the Pioneer output into the portable radio on a couple of connections around the volume knob, and it seemed to amplify pretty good, so now everything is up and running.

My system uses old electronics. There aren't any microchips in anything. However, there are large transistors, resistors and so on. My question is, are the older components more resistant to an electromagnetic shock wave from a nuclear blast, than microchips? Does a shock wave permanently damage chips, or just temporarily incapacitate them? Does a shock wave damage the old large transistors?

I'd have to agree.... ;). But how did the EMP generator work in the movie Matrix to stop the sentinels and not take out the ship or any other nearby ships ........ LOL... hehe I guess if you were still connected in the "Matrix", you couldn't use the EMP.

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if

Not to mention people who have gold teeth or any other metal in their body?

If a nuclear blast goes off (God forbid) close enough to damage electronics, you're going to have a lot more to worry about than said electronics...

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The distinction is not between "old" and "new" electronics, nor is it between discrete transistors and integrated circuits and/or microprocessors. It is between solid state and non-solid state electronics (vacuum tubes). The latter is vastly more resistance to voltage surges caused by nuclear weapon-induced Electromagnetic Pulse (EMP) (there is no "shock wave" involved). Just as it is vastly more resistant to EMP caused by (nearby) lightning strikes...EMP is EMP.

Solid state electronics tend to be susceptible to destruction by over-voltages that a vacuum tube (valve) circuit would not even notice. Furthermore, the small physical sizes made possible by solid state active electronic components make them even more vulnerable to local arcing.

Nuclear weapon-induced EMP has been demonstrated to cause damaging voltage surges at ranges to the thousands of miles: Well beyond all other nuclear weapon effects.

webpa

Finally, something resembling a real answer. May I add a bit of clarification?

"EMP" can be interpreted as a short burst of Really High-Powered radio-frequency (up into the low gigahertz at least) travelling past the equipment in question, "Really High" being high enough to induce lots of current at high voltage in conductors like the wiring in any circuit, including power lines. "Lots" and "high" being enough to overcome the usual protection measures built into consumer (and ordinary military) gear.

The dumbed-down (Congress-friendly) version:

Compare lightning:

Some other relevant stuff:

Well, actually, the tubes would notice the pulse because they'd likely arc over internally just as the semiconductors would due to the high voltages induced on their terminals from the EMP. The semiconductors (from ancient Ge transistors to modern high-density chips), however, will experience catastrophic overheating from the EMP-induced current and/or voltage puncture, while tubes are more likely to be able to dissipate the heat and go on functioning just fine afterward. Still, some of their associated circuitry may be permanently adversely affected (like punctured caps and melted inductors frinst).

Some of that is due to powerline conduction; most of the EMP falls below lethal-to-circuitry levels pretty quickly; inverse-square, remember?

Mark L. Fergerson

latter

is

EMP.

over-voltages

components

------------------- Only vast antennae like the grid or phone system are really vulnerable, the small electronic device is not in much danger if not from blast, as only near the blast does the EMP get anywhere near high enough for its scale of induction. Since the advent of fiber telecomm, it is believed it would be harder than ever before to disrupt telecomm with EMP, it would be easier to ground-nuke what you want to stop.

-Steve

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The first US experience, a high altitude detonation in the South Pacific, seems to have produced large-scale power grid failure in Hawaii. This is not a sure thing, since we didn't expect it and did not instrument for it. The USSR and France probably have more data than we do, since they did quite of number of high-altitude bursts that seemed to be designed specifically for EMP data collection (and maybe, EMP-enhancement).

Critical point is that the Hawaii incident involved a power grid several thousand miles from the detonation. It was not conducted there, but radiated. Inverse square law works of course, but the phenomena at the source has some very large numbers to start with. webpa

This was also my understanding -- that a single high altitude burst over Ohio of a weapon of the largest size that the Soviets had been known to build would take out most unprotected electronics in the eastern half of the country, and a large portion of the western half. I don't know that for sure, but only remember this from a discussion between weapons engineers that I overheard in around 1986 or 1987 (I was working in electronics countermeasures at the time, but as an ME, not an EE). It was also my understanding (from that same discussion), that house wiring a thousand miles away or more would induct many thousands of volts per linear meter, causing many house fires and blowing most connected devices which are not specially protected. Also automobile wiring would burn out components over most of the area mentioned. Discreet passive components not connected to circuitry would likely survive in most area, but most CMOS would be toast.

Mark 'Sporky' Staplet> The first US experience, a high altitude detonation in the South Pacific, seems

Yup. A power grid is effectively a large aperture antenna whereas individual devices can't intercept much energy. IIRC from the Hawaii incident once power was restored most TVs, radios, etc. that had been connected to the grid worked fine afterward.

Again, how "focused" the energy is has much to do with it. The "EMP bomb" site I linked to shows what amounts to a radiator with lots of gain in one direction. If the source is omni I'd still expect much less permanent damage.

Mark L. Fergerson