2 Apr
2024
2 Apr
'24
6:26 a.m.
ASCII Graphic of an EMP:
Much EMF
_____
| |
| |
--------------- ---------
zero EMF
t=0 t= very short time
What frequencies would you like.... Fourier would suggest that many of
them are there :-)
:-)
Kindest regards,
Doug Jackson
em: doug(a)doughq.com
ph: 0414 986878
Follow my amateur radio adventures at vk1zdj.net
On Tue, 2 Apr 2024 at 16:04, Just Kant via cctalk <cctalk(a)classiccmp.org>
wrote:
Accordimg to certain individuals on this list, going
back a few years,
electronics/computers can be damaged due to an electrical storm, presumably
very intense activity, even while off. Go look through the archives.
I knew people back in the 80s that said they could "torque" certain
frequencies with a cb radio in the vicinity of a car wash and turn the
whole joint on! Vending machines are/were said to be similaely vulnerable.
Such is the basis behind emc testing. I should know. A specific component
is wrapped with wire say, or is placed in front of various antennas, and
currents are pumped through or frequencies are directed at the item to see
if it fails. Or fries (very uncommon). Specifications are provided as to
what tests need to be conducted, literally, or radiated. If the item fails,
additional work is required to keep the item in spec so that it doesm't
fail in the field.
Which frequencies are present in an EMP I couldn't tell you. But I have
to believe they delivered with considerable power. I did work like that
back in the 80s. In general I don't think too much equipment was radiation
hardened back then. It was believed then the threat would be from a neutron
bomb. A high altotude emp strike probably wouldn't affect much. But I'd
certainly be concerned about one in the vicinity of a server farm or a
military complex may frig up quite a bit. You don't havento knock out
everyone's electronics in order to frig up a society or crucial portions of
it. I'm binging Pikard at the moment. Their comms have limited
effectiveness because relays (repeaters?) don't exist in 2024.
Sent with Proton Mail secure email.
On Monday, April 1st, 2024 at 9:46 PM, Christian Kennedy via cctalk <
cctalk(a)classiccmp.org> wrote:
On 4/1/24 17:42, CAREY SCHUG via cctalk wrote:
> Will things like PDAs and tablets, powered off and stored inside steel
ammo boxes survive?
Yes, as will most contemporary electronics, even without elaborate
protection.
The amount of current induced in a device by EMP is a function of the
number and length of conductors; most modern electronics are unlikely to
have an issue given relatively short conductor lengths. Automotive
ECUs, in particular, are unlikely to be affected, as they're equipped
with seriously clamped lines and generally have been tested in lightning
simulators (EMP looks like lightning, but EMP has a much faster rise
time, much higher voltages, and vastly higher currents); likewise the
commercial electrical grid is likely to be largely unaffected due to
existing lightning protection. If your device can withstand a nearby
lightning strike, it's probably going to survive a high altitude EMP
event.
The biggest problem for semiconductor devices is from neutron flux when
under power, hence weird solutions for military systems where a PN diode
will be used to trigger a crowbar on the power supply (ionizing
radiation arrives well in advance of the neutrons). The upshot is that
warfighting systems will recover, although the same probably can't be
said for the warfighters.
Yes, I spent entirely too much time in this space in my misspent youth.
Note that none of this is to suggest that all electronics will survive,
but the doom and gloom people associate with high altitude EMP, and
Carrington events in particular, are generally overblown.
--
Christian Kennedy, Ph.D.
chris(a)mainecoon.com AF6AP | DB00000692 | PG00029419
http://www.mainecoon.com PGP KeyID 108DAB97
PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97
"Mr. McKittrick, after careful consideration…"