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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: GPT on August 15, 2003, 06:31:00 PM
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I just reboted my amiga with two walkie-talkies. :python:
I hade just repaird a couple of walkie-talkies and was testing them.
And I noticed that the speakers amplified the click sound from the 'talkies and the monitor wobbled.
As I am, I can't strain the urge for clicking more with the 'talkies.
So suddenly poof the computer reboots...
I'm no expert, but I think the hi-freqency signal from the 'talkies conducted (I'm not sure that's the right word) to the computer and some kind of error mecanism in the computer detected that something was wrong and rebooted, when the disturbance became to much.
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Which Amiga model?
Metal or plastic case?
Ciao
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Yep, the RF from your radios probably did conduct on a trace somewhere in the Amiga but there wasn't any "error mechanism" involved. Induction was enough to cause a bit or two (or more) to flip on a bus et voila! The computer goes down.
My 2 meter (144-148 MHz) transciever will cause my computers to reset if I xmit while close to them. It's not that uncommon for RF to affect machines that aren't properly sheilded.
BTW, what brand and model are these radios?
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I don't know.
I am sheilded with a ELBox Tower.
But it could be that I have removed one side from the tower so I easly can reach for the ppc board or something similare.
So if I assamble the side to the tower then it should sheild the RF signals.
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Very interesting, so now we know how to sabotage PC's too :-D
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Better off with a proper EMP weapon.
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If its doing that to your Amiga through steel sheeting, think what its doing inside your head. :nervous:
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KennyR wrote:
If its doing that to your Amiga through steel sheeting, think what its doing inside your head. :nervous:
That's dependant on frequency. Different RF wavelengths heat different parts of the body. If they're 49MHz (wavelength = 6.12 meters) radios, there's very little heating effect to the stuff in your head. The head is just too small. And 5 watts (most probable max output for a handheld) isn't going to heat you up much anyway. However, if they are 400MHz (wavelength = 1.33 meters) units, your head DOES get the most of the heating effect. But, like I said, 5 watts of transmit RF doesn't do much. The computer really is in much more danger than you at these low levels. A kilowatt or so and it's a different story.
As for athermal effects of RF, the jury is still out, it seems.
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GPT wrote:
So if I assamble the side to the tower then it should sheild the RF signals.
Not neccesarily. Just because you have all the case parts on doesn't mean your computer is properly shielded. There are other factors to concider. For example, how long is the path from the shield to earth ground (not mains ground)? If it just happens to be the right length to be resonant on the xmit frequency, it will act as an antenna. Then, you have a system gound with an RF voltage on it which isn't a very good ground for electronics! ;-) This, in essence, is the problem I have with my compters and my handheld. The path to earth ground is too long and RF gets into the system through the ground leg.
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Floid wrote:
Better off with a proper EMP weapon.
Like a nuke detonated outside the atmosphere? :-)
The only way a nuke can be practically used in a war.
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N7VQM wrote:
That's dependant on frequency. Different RF wavelengths heat different parts of the body. If they're 49MHz (wavelength = 6.12 meters) radios, there's very little heating effect to the stuff in your head. The head is just too small. And 5 watts (most probable max output for a handheld) isn't going to heat you up much anyway. However, if they are 400MHz (wavelength = 1.33 meters) units, your head DOES get the most of the heating effect. But, like I said, 5 watts of transmit RF doesn't do much. The computer really is in much more danger than you at these low levels. A kilowatt or so and it's a different story.
Even without heating there is still a potential for damage. EM pulses create current in any conductor, and brain tissue is a pretty good conductor. Considering the human brain is the most complicated object created by mankind or nature (that we know of), who knows what these surges of current in the brain could be doing?
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KennyR wrote:
N7VQM wrote:
That's dependant on frequency. Different RF wavelengths heat different parts of the body. If they're 49MHz (wavelength = 6.12 meters) radios, there's very little heating effect to the stuff in your head. The head is just too small. And 5 watts (most probable max output for a handheld) isn't going to heat you up much anyway. However, if they are 400MHz (wavelength = 1.33 meters) units, your head DOES get the most of the heating effect. But, like I said, 5 watts of transmit RF doesn't do much. The computer really is in much more danger than you at these low levels. A kilowatt or so and it's a different story.
Even without heating there is still a potential for damage. EM pulses create current in any conductor, and brain tissue is a pretty good conductor. Considering the human brain is the most complicated object created by mankind or nature (that we know of), who knows what these surges of current in the brain could be doing?
I think some members of the Amiga Community have had the RF sheilds off their machines for too long, often known as the Amuobekim (pronounced Am ooo bee kim) effect.
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@KennyR
Did you forget about the last sentence of my post or did you ignore it?
It's not yet known just how RF feilds below the ionization level affect biologicial mechnisms. And, while the chemical soup in the brain is a decent conductor, it is not a good inductor. If it was, I doubt we would have survived this long concidering the RF pulses created by lightning strikes.
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N7VQM wrote:
Did you forget about the last sentence of my post or did you ignore it?
Sorry, my eyes saw "thermal" there and not athermal.
It's not yet known just how RF feilds below the ionization level affect biologicial mechnisms. And, while the chemical soup in the brain is a decent conductor, it is not a good inductor.
True.
If it was, I doubt we would have survived this long concidering the RF pulses created by lightning strikes.
True as well. But... Anecdotal evidence would suggest that those close are knocked unconcious even without having any of the current pass through their bodies. It could be the blast wave and/or the flash and bang as well, of course.
There's also reason to believe that EM fields disrupt the mental processes. Experiments with magnetic fields along the brain causes subtle mood changes or memory recollections. Until there's evidence to the contrary, I'll do the opposite of everyone else and assume that cellphones and other EM transmitters can actually affect the brain. When people are making money out of dismissing unproven science, its usually a safe bet that the science is right and that they are wrong. How many years did the tobacco industry deny smoking caused cancer?
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ALL computers are subject to radio interference no matter what. Sooooo, why not reboot someone else's pc? :-D
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KennyR wrote:
There's also reason to believe that EM fields disrupt the mental processes. Experiments with magnetic fields along the brain causes subtle mood changes or memory recollections.
Goggle "schuman resonance" for some interesting reading. In particular, compare the frequencies of Schuman Resonance to the various frequencies of human brain activity.
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Atleast the manual for my Tower states that it should sheild of the computer from any kind of disturbance.
And it also hade a OK mark that is suppose to verify that the manual is right.
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'Any kind of disturbance' probably is talking about what you would normally encounter. To be properly shielded, you need a proper 'faraday cage'. I had to use one when I was carrying out leakage current measurements for my Masters. I was measuring currents of the order of nano - pico, and in the lab there were sooo many sources of noise.
E/m noise is all around us in this technological age. Strip lights oscillating, monitors/TV screens, two massive peaks in the e/m spectrum from any nearby mobile phone masts ... :-o
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E/m noise is all around us in this technological age. Strip lights oscillating, monitors/TV screens, two massive peaks in the e/m spectrum from any nearby mobile phone masts ...
And to think we still use Magnetic Media... :-o
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Something for the stoners to try... "Dude, I rebooted my head!!"
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The ICs have a destructive way of collapsing, than the brain that acts as an analog system which can compensate.
As for the thermal effects you need a lot of energy to warm up the tissue because it's full of water (that means it has a high caloric capacity).
The only thing to consider as dangerous are the long-term effects...
P.S. Long time ago, someone with a walkie-talkie turned off my portable radio-cassette player on the beach (just as if it drained the batteries' power) !!!
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