Dave Shrader wrote in message news:Xu36c.33004$po.292953@attbi_s52...
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.

So, it is possible that pressing the PTT or the ON/OFF switch causes the
necessary spark. Remember the Apollo ground fire. A switch/spark caused
an oxygen explosion.

Actually, anyone who has worked in the offshore oil industry will be
familiar with the concept of intrinsic safety. This requires that no
electronic instrument shall be able to ignite a mixture of air and
inflamable vapour or gas. All handheld radios used on rigs are
intrinsically safe, making them far more expensive than the standard
variety.

I very much doubt that cell phones are buit to intrinsicly safe
standards, and under those circumstances I would certainly not feel
safe near someone yacking while filling.

So, an interesting querstion is; does your phone conform to UL
requirements for intrinsic safety? And if not, why are you using it
in an area where an explosive gas air mixture is possible?

Cap

Jim Yanik wrote:
Tim Auton tim.auton@uton.[groupSexWithoutTheY] wrote in
:
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...

You would have to have every phone in the nation ring every couple of
hours. They're not going to be stupid enough to have the phone both
switched on and connected to the bomb until the last minute.

Actually,they have to have it active before they enter 'enemy' territory,as
citizens there often notice some stranger fiddling with a package and then
leaving it behind;the common indicator a bomb has been placed.

So you're defining where the last minute is. Israel is tiny and most
of it is within an hours travel of "hostile" territory. My point about
the rate at which you would have to call mobiles stands.

You would have to disable every RF device in the nation to stop that
means of detonation. Removing RF communication from the population
means the terrorists have won. The only way to beat them is to carry
on doing exactly what you are doing now - changing your behaviour is a
victory for the terrorists. I'm British, I've lived under the threat
of terrorism (the comparatively mild IRA) almost my entire life (I'm
28). You just accept the risk - which is very, very small compared to
car accidents etc. etc. etc.

Changing laws and changing behaviour is *exactly* what they want. ****
them. The only thing you can do is report suspicious packages at train
stations etc. Other than that, just ignore the *******s and get on
with your life - if you do anything else they have won.

If you're scared then they have won. That's why it's called TERRORism.
Look at the odds - if you're not scared of crossing the road you
shouldn't be scared of terrorism.


Tim
--
Love is a travelator.

Well said.

"Tim Auton" tim.auton@uton.[groupSexWithoutTheY] wrote in message So
you're defining where the last minute is. Israel is tiny and most
of it is within an hours travel of "hostile" territory. My point about
the rate at which you would have to call mobiles stands.

You would have to disable every RF device in the nation to stop that
means of detonation. Removing RF communication from the population
means the terrorists have won. The only way to beat them is to carry
on doing exactly what you are doing now - changing your behaviour is a
victory for the terrorists. I'm British, I've lived under the threat
of terrorism (the comparatively mild IRA) almost my entire life (I'm
28). You just accept the risk - which is very, very small compared to
car accidents etc. etc. etc.

Changing laws and changing behaviour is *exactly* what they want. ****
them. The only thing you can do is report suspicious packages at train
stations etc. Other than that, just ignore the *******s and get on
with your life - if you do anything else they have won.

If you're scared then they have won. That's why it's called TERRORism.
Look at the odds - if you're not scared of crossing the road you
shouldn't be scared of terrorism.


Tim
--
Love is a travelator.

The ideas are getting better but are you going to be the one to explain to
people's families that it was for the public good that you were transmitting
a signal designed to set off a bomb in a crowded place? It should get the
terrorist and the couple of dozen people behind him waiting to get through
the check point.

"KLM" wrote in message
...


An idea just occurred to me.

You notice those electronic anti-shoplifting interrogators at the
checkout counters?

Why not include a circuit in every cellphone that will cause the
answer bell to ring when anyone carrying a cellphone crosses one of
these interrogators. Maybe have the circuitry activate a different
ring tone or ring pattern from the normal call ring. Its extremely
short range and won't interefere with normal cellphone use.

It will set off a cellphone bomb or at least ID a suspicious cellphone
owner who can be asked to show the phone (any cellphone modifications
will be noticed immediately) or can be called aside for further
inspection. This will enable security people in places like train
stations, bus stations and airports to quickly screen crowds.

The same interrogating circuitry could be installed in metal detector
security gates.

Its rare to be able to go anywhere without encountering one of these
interrogators these days. A bomb carrying cellphone triggered
terrorist will have a hard time moving around without attracting
attention somewhere.

------------------------------------------------

On a different discussion point, picture the recent Spanish train
bombings (10 set off.) Had the train installed cellphone signal
blocking equipment most of those bombs would probably not have been
set off. Calls on emergency workers commuting by train could easily
have been relayed by the train's onboard PA system. Calls out can be
made from on-board public pay phones. Or can the signal blocking be
effective only for incoming calls and leave out going calls
unrestricted? Airlines blocks incoming calls. Outgoing calls can be
made from anywhere during flight through the aircraft's phone system.

On Wed, 17 Mar 2004 21:38:29 -0500, Ben Bradley
wrote:

In rec.radio.amateur.antenna,

( I suppose this is on RRAA because cell phones have antennas )

sci.electronics.design,sci.electronics.basics, 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....

Call phones have become the trigger of choice for terrorist bombs.

The Israelis should get a telemarketer's speed dialer and constantly
dial away... boom... boom... boom...

This might already be illegal there (not that that would stop a
government). I've heard that various parts of Europe have much
stronger privacy laws than the US, so there's little or no
telemarketing.

ROTFLMAO!

Of course, in the USA, one could put the cell number on the
national DO-NOT-CALL list, then only an "illegal" telemarketer would
trigger the bomb.
Or Church, politician, or charity, or any other 501C3 orginization, or
.....


Bombers might figure ways around this (especially if they search
Usenet), such as a cellphone answering circuit and a "dee tee em eff"
decoding circuit. I wouldn't want to spell it out for them...

I'd think that would be a given. Oops...wrong number.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


...Jim Thompson

-----
http://mindspring.com/~benbradley

Mark wrote,

Jan Panteltje wrote:

snip

unfortunately its not likely to happen. Little things like the clearly
observable FACT that decades of repressive behaviour towards the
palestinians has NOT resolved the problem, but made it WORSE, seem to have
escaped the notice of successive israeli governments. so much for "an eye
for an eye" being of any practical use.

Um, Israel is backed up against the Mediterranean. What
impenetrable barrier are the "Palestinians" backed up against?

Mark L. Fergerson



Israeli fanaticism.

Tom Donaly

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

Please add me to the Do Not Bomb list! Aren't all terrorists required to
avoid
bombing those registered? Just like telemarketers?

David

Changing laws and changing behaviour is *exactly* what they want. ****
them. The only thing you can do is report suspicious packages at train
stations etc. Other than that, just ignore the *******s and get on
with your life - if you do anything else they have won.

If you're scared then they have won. That's why it's called TERRORism.
Look at the odds - if you're not scared of crossing the road you
shouldn't be scared of terrorism.


Tim
--
Love is a travelator.

A voice in the wilderness! Very well put.

David

I noticed that the appearance of the no cell phone signs came around
the
same time that gas stations started running audio commercials through
speakers at the pump.

Interesting observation.

we dont have audio commercials at the pump here in New Zealand
(thankfully),
but we do have the no-cellphone signs though. It is likely to be no more
than corporate paranoia - can we get our asses sued off if we dont tell
people to do this.......I suggest we blame the lawyers


Cellphones can only ignite gasoline fumes in the vicinity of
cars prone to unintended acceleration.

David

I read in sci.electronics.design that David Williams ddR_E_M_O_V_Ewilli
wrote (in )
about 'Cellphones and Bombs', on Thu, 18 Mar 2004:
Aren't all terrorists required to
avoid bombing those registered?

Sounds like the sort of law they pass in France. Or Tennessee. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk