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On Thu, 18 Mar 2004 05:39:21 +0000, Tim Auton
tim.auton@uton.[groupSexWithoutTheY] wrote: Active8 wrote: [bombs] Do you all think that tangos are dumb enough to trigger the bomb with the ringer or would the detonator answer first and listen for a DTMF sequence. Hmmm? Achmed the bomb maker gets a wrong number just as he's connecting the thing. I very much doubt they bother with DTMF decoders. I mean, how often do you get a wrong number? I've had about 4 in my life. They'll just connect the ringer (or vibrate function) to the detonator (with whatever minimal circuitry in between is required - I've never used a detonator!) and then only turn the phone on at the last minute. It's not dumb to design a remote detonation system that requires the absolute minimum of specialist knowledge and equipment to construct. Tim New anti-terrorist weapon = telemarketers. They call everybody. Should wipe out the bomb makers in about a week. Dave Head |
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Jim Thompson wrote:
I was struck by a thought when I heard the latest Palestinian terrorist trick is to send a kid through the border with a back-pack bomb triggered by a cell phone.... The Israelis should get a telemarketer's speed dialer and constantly dial away... boom... boom... boom... Not really. The technology is far better. Here you can get those industial mobiles with a serial output. You can send an SMS which's string can be decoded by software of you own microcontroller. Rene -- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net |
On Thu, 18 Mar 2004 14:08:26 +0100, the renowned Rene Tschaggelar
wrote: Jim Thompson wrote: I was struck by a thought when I heard the latest Palestinian terrorist trick is to send a kid through the border with a back-pack bomb triggered by a cell phone.... The Israelis should get a telemarketer's speed dialer and constantly dial away... boom... boom... boom... Not really. The technology is far better. Here you can get those industial mobiles with a serial output. You can send an SMS which's string can be decoded by software of you own microcontroller. One could easily imagine a semi-smart anti-convoy bomb that could be remotely triggered by a hidden operator to go off after a programmable delay (with password), so signal jamming would be relatively ineffective. Nasty, and hobbyist-level technology once you have the phone. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
In message , Guy Macon
writes [Snipped] It's silly to worry about cell phones when every car that drives in has a high-voltage ignition system under the hood, 12V spark-producing switches in the door frames, and a hot catalytic converter underneath the car. The RF/electrical bit seems like a red herring to me, but I suppose it would be better to give full attention to the flammable liquid you're pumping rather than a telephone conversation. -- Syd Rumpo |
On Wed, 17 Mar 2004 21:33:43 GMT, Dave Shrader
wrote: John Michael Williams wrote: SNIP However, the first radios transmitted sparks, so in principle it should be possible to transmit near a long wire separated by a small gap from ground or another wire and get a small spark. So, I decided to try an experiment. SNIP There is one other potential source for a spark that you did not investigate. A make/break contact in a switch causes sparks when opened. The US Military specifies special shielded switches for their explosive, gas vapor, etc., environments. This reminds me of a story... (pause while room clears out). Years ago I was an engineering student working for Cadillac Motor Car. Electronic fuel injection was new then, and there had been a couple of fires in the field that were suspected to have been caused by leaky fuel lines, which were at higher pressure than on the old carbureted cars. There were competing theories, however, as to what exactly was setting off the fire. I got assigned to help the guy doing the experiments to find out. He had a car fitted with a plexiglas hood, topped by a small tower with a high-speed movie camera pointing down for a good look at anything happening in the engine compartment. Two fire extinguishers were arranged to cover the under-hood area, and a fuel vapor sensor was also installed there. The way it was supposed to work was that he would drive and I would operate the hand-pumped sensor, and at the first sign of fire he would trigger the extinguishers. We ran all the tests at the GM Proving Grounds in Milford, Michigan. We tried making leaks in the fuel injection hoses. We had gas spraying all over under the hood, collecting in pools on the hot exhaust manifold. We tried poking holes in the spark plug wire insulation. Nothing, no fire. Finally I got a bright idea, and loosened the ground for the air conditioner compressor clutch. The idea was that this was a big inductor, and if the circuit opened there would be a big spark. Then all we needed to do was get the wire to bounce. We tried swerving from side to side, and driving on bumpy tracks, but no deal. I was *sure* that this spark would do the job, but we couldn't tell if we were really getting the spark. So finally I stood on the hood, holding on to the camera tower, so I could see for myself if there were sparks. He drove down the bumpy road one more time, and I did in fact see a spark: The high-speed movie shows the fire spreading out from it, more and more on each frame. Also on each frame was the back of my head, moving away more and more on each frame, until the extinguishers doused everything. What a rush! Them was the good ole' days..... Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis www.daqarta.com |
Paul Burridge wrote:
I've never been blown up yet. You've never died yet, either. :-) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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One thing that may set off a detonator is a RF field with a wavelength in
the order of the detonator leads. From the time I worked with detonators on oilrigs, an absolute radio-silence was required till the charge was safely lowered down the borehole. Wim |
On Thu, 18 Mar 2004 10:30:45 GMT, Dave Head wrote:
On Thu, 18 Mar 2004 05:39:21 +0000, Tim Auton tim.auton@uton.[groupSexWithoutTheY] wrote: Active8 wrote: [bombs] Do you all think that tangos are dumb enough to trigger the bomb with the ringer or would the detonator answer first and listen for a DTMF sequence. Hmmm? Achmed the bomb maker gets a wrong number just as he's connecting the thing. I very much doubt they bother with DTMF decoders. I mean, how often do you get a wrong number? I've had about 4 in my life. They'll just connect the ringer (or vibrate function) to the detonator (with whatever minimal circuitry in between is required - I've never used a detonator!) and then only turn the phone on at the last minute. It's not dumb to design a remote detonation system that requires the absolute minimum of specialist knowledge and equipment to construct. Tim New anti-terrorist weapon = telemarketers. They call everybody. Should wipe out the bomb makers in about a week. Dave Head Not if they're on the Do Not Call list ;) -- Best Regards, Mike |
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