Guy Macon http://www.guymacon.com wrote in message ...
See my post titled Intrinsic Safety

I did. Thanks.

It appears that the laws involved pertain to manufacturers
and commercial operations. So, I think none would
govern use of a cell phone while gassing up.

I once wired a farm house, but that was before the NEC
included the concept, I think.

John

John Michael Williams

Hi Jeff.

Thanks. Comments below.

Jeff Liebermann wrote in message . ..
On 17 Mar 2004 12:02:15 -0800, (John Michael
Williams) wrote:

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.

There were few spark transmitters mounted in automobiles. They were
just too inefficient, big, and clumsy to be functional. Transmitters
in vehicles really didn't start until tube type transmitters became
popular. The problem was that the typical mobile radio used a
dynamotor (motor-generator) combination to generate the necessary high
voltages. With the radio and dynamotor mounted in the trunk of the
vehicle, there was a good chance that gasoline fumes would accumulate
in the trunk of the vehicle and be ignited by the spark from the
dynamotor commutator. See the photo of the 80D at:
http://www.telmore.com/ka1nvz/old_tw...ola/49-59.html
The dynamotor is the black cylinder near the handle. The 140D was
twice as big and heavy.

Ships around the turn of the 20th century transmitted morse code by
spark, I think.


Back in the 1960's, my 1960 Ford Falcon had an assortment of Motorola
80D and 140D radios in the trunk. I experienced a small explosion in
the trunk ignited by the dynamotor. I had filled up the gas tank at
the local gas stop (for 19 cents per gallon). Warm weather caused it
to expand and leak vapour into the trunk. Key the transmitter, the
dynamotor starts, sparks, and boom.

I then attached a 1.2 m monopole antenna to an oscilloscope.
This antenna has a Schottky hot carrier diode and impedance
matching resistors builtin.

Lovely. A harmonic generator. Any reason you want lots of harmonics?
Shottky diodes or any other non-linear device, do not belong in
antenna matching circuits.

It's home made, but it's probably
as good as any other wire about that long.

Wrong. Optimum for CB is either a 1/4 wave monopole (102 inches) or
two of them to form a half wave dipole.

So, first conclusion: To get even a 1 V spark would take a
wire at least 9 m long, all somehow kept within 1 m of the
transmitter. Thus, it appears it is not feasible to create a
hazardous spark with a CB at a gas station.

Find a 4 watt flourescent light. Attach a 1/4 wave antenna to your 5
watt CB radio. Transmit. Hold lamp in hand and touch the end of the
102" antenna. It will light when you talk. (Note: With AM
modulation, you only get 5 watts when you yell into the microphone.
Without modulation, you only get about 2.5 watts of RF).

Interesting idea. I would have thought that a tube would require
more V than a neon lamp to get started. I'll try it if I can
find a lamp.

What you seem to be suggesting is that I simply connect the
lamp to the 1/4 wave receiving antenna, right? Why introduce
my hand? For ground on the other lamp contact?

I don't see the point of attaching a long
wire to the CB, because they don't come with long bare wires.
Clearly, I could get a good spark by attaching a wire to the
CB batteries, and avoid all the RF stuff!

Now, ask
yourself what voltage is required to light the flourescent lamp.

In order to get a spark, you need to generate enough voltage to ionize
the air between the contacts. That's about 20KV/inch. If we
eliminate the antenna, 5 watts of RF into 50 ohms will generate:
P = E^2 / R
E = 16v rms
E(peak) = 1.4 * 16 = 22 volts
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches
Kinda small, but given a microscope, a 1 mil spark gap will arc. Of
course the VSWR protection circuity in the transmitter will instantly
shut down the transmitter when it arcs, but that takes a few millisec.

22 V is a lot more than I could get with a 1 m monopole: I only
got 100 mV peak to peak. It appears my 1 m wires
were too short; but, if I use a long wire, the distance from the
transmitter will lower the power transfer to some
of the wire, won't it? Or, I'll have to move away, into the
far field--but that will also lower the power.

There's no question 5 W is enough to make a spark of arbitrary
size, given an inductor somewhere around, but I don't see where
the 50 ohms comes from, if I'm looking for a spark caused by the RF?


Notice that this is a voltage phenomenon, and is not dependent upon
the power level. Therefore, an antenna that offers a voltage step-up
will generate a higher voltage. However as the antenna is in the air
and nowhere near a close enough ground to arc, it doesn't matter. If
there's gonna be any arcing, it will be between the xmitter output and
the base of the antenna.

The transmitter antenna is coated with about 3 mm of rubber; I think
cell phones are the same way. A spark has to come from the RF,
I think. There is a BNC connector, but that implies complete
shielding (even flame suppression!) at the antenna base.

I have a telescoping antenna intended for a receiver that is bare
metal, though. I could substitute it.


The typical mobile FM transmitter of the day (1960's) cranked out
between 15 and 150 watts. Most were around 75 watts. Run the calcs
again for 75 watts and see if the gap is more reasonable (I'm lazy).

The next question is how much heat is necessary from the arc to ignite
the gasoline vapour. I'll leave that as an exercise for when I have
more time to burn. Gotta get back to lying and cheating on my taxes.

I think if I can see the spark, it can ignite gas vapor,
provided the flame had a path out of the gap.

John

John Michael Williams

On 20 Mar 2004 23:28:38 -0800, (John Michael
Williams) wrote:

Ships around the turn of the 20th century transmitted morse code by
spark, I think.

The Lusitania, Mauritania, Titanic, and Olypic all ran on coal. No
gasoline in sight. Later vessels ran on bunker C fuel oil, which is
more like tar than gasoline. I don't think one has to worry about
sparks on such a vessel unless it's finely devided coal dust, which
finished off the Lusitania in a secondary explosion after the torpedo.

Interesting idea. I would have thought that a tube would require
more V than a neon lamp to get started. I'll try it if I can
find a lamp.

Neon lamp needs about 60 volts to light and 40 volts to stay lit. The
4 watt flourescent tube wants at least 90 volts to start, and I think
(i.e. guess) about 50 volts to stay lit.

What you seem to be suggesting is that I simply connect the
lamp to the 1/4 wave receiving antenna, right? Why introduce
my hand? For ground on the other lamp contact?

Yep. You're the ground. You should be fine with a 5 watt CB and a 1/4
wave whip. The high voltage point is near the tip. However, don't
try it with an illegal CB linear. You'll get an RF burn for your
troubles.

Incidentally, there are cell phone antennas with lights in them.
http://cellphones-accessories.com/12stobligcel.html
They're LED's which require much less power to light than a 4 watt
flourescent bulb. Still, it's kinda interesting.

I don't see the point of attaching a long
wire to the CB, because they don't come with long bare wires.
Clearly, I could get a good spark by attaching a wire to the
CB batteries, and avoid all the RF stuff!

Exactly. Same with an open relay contact or toggle switch. However,
don't foget that you need containment to create an explosion.
Sparking the DC inside the trunk is the mostly likely location.

22 V is a lot more than I could get with a 1 m monopole: I only
got 100 mV peak to peak.

The 22 volts peak is at the RF connector. I'm assuming that if there
is a spark gap, it will be in the coax cable or associated antenna
connectors.

It appears my 1 m wires
were too short; but, if I use a long wire, the distance from the
transmitter will lower the power transfer to some
of the wire, won't it? Or, I'll have to move away, into the
far field--but that will also lower the power.

Inverse square law. Double the distance, and you get 1/4 the power.
For a fix load resistance, 1/4 the power is 1/2 the voltage. However,
you'll get vary bad coupling efficiency with such an arrangement. I
could grind the near field equations but you'll never get ALL the
power (5 watts) delived to your random wire pickup. Think resonance
and close coupling if you want to do better.

There's no question 5 W is enough to make a spark of arbitrary
size, given an inductor somewhere around, but I don't see where
the 50 ohms comes from, if I'm looking for a spark caused by the RF?

That's the approximate impedance of the antenna as found on a typical
mobile installation. Again, I'm assuming that if there is a spark to
be found, it will be at the coax ends or connectors. They're all 50
ohms.

The transmitter antenna is coated with about 3 mm of rubber; I think
cell phones are the same way. A spark has to come from the RF,
I think. There is a BNC connector, but that implies complete
shielding (even flame suppression!) at the antenna base.

A BNC connector is quite open but is good for maybe 150 volts of RF.
However, all it takes is a sloppy coax connection, with some of the
braid wires slopped around near the center pin of the BNC, and you
have a potential spark gap.

I have a telescoping antenna intended for a receiver that is bare
metal, though. I could substitute it.

Won't make much differnce. At 0.001" gap necessary for a spark with 5
watts can only happen with a defective installation.

I think if I can see the spark, it can ignite gas vapor,
provided the flame had a path out of the gap.

I beg to differ. The ignition of a gasoline oxygen mixture requires a
specific amount of energy to ignite. Anything less will not produce
the requiste chemical reaction. Think spark plug heat ranges and glow
plugs in model airplanes. I'll grind the numbers if you want, but
it's now midnight, I'm tired of waiting for Windoze update, and I'm
going home.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
#
# 831.421.6491 digital_pager AE6KS

I read in sci.electronics.design that Jeff Liebermann
wrote (in mppp50ho4dr08ahkb3dlbqkcfkp0ih
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches Kinda small, but given a microscope,
a 1 mil spark gap will arc.

But it takes about 350 V to do so. The relationship between voltage and
gap length is very non-linear below about 500 V.
--
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

Jeff Liebermann wrote in message . ..
On 20 Mar 2004 23:28:38 -0800, (John Michael
Williams) wrote:

snipped lots of good stuff

I think if I can see the spark, it can ignite gas vapor,
provided the flame had a path out of the gap.

I beg to differ. The ignition of a gasoline oxygen mixture requires a
specific amount of energy to ignite. Anything less will not produce
the requiste chemical reaction. Think spark plug heat ranges and glow
plugs in model airplanes. I'll grind the numbers if you want, but
it's now midnight, I'm tired of waiting for Windoze update, and I'm
going home.

The ignition of a gaseous oxygen-gasoline mixture, or a (potentially
more sensitive) hydrogen-oxygen mixture does require a specific
minimum amount of energy, which depends on the partial pressures of
the oxygen and the fuel, and - IIRR - the partial pressures of any
inert diluent gases around.

Lesser amounts of energy can induce the requisite chemical reaction,
but the reaction will fizzle out, rather than providing enough energy
to ingnite the surrounding shell of a gas mixture and produce a
self-propagating flame front.

The controlling relationship is between the volume of the sphere in
which the reaction is first initiated, and the surface area of that
sphere - if the intial volume is too small, not enough energy is
released to heat the surrounding shell of gas to the ignition
temperature.

Once you've got the basic idea,the thermodynamics is pretty
straightforward.

I had to work through the equations many years ago for an experiment
intended to monitor the process in which one of the "Dewar benzenes"
converted itself to normal - Kekule's - benzene, which is an
enormously energetic process, involving about an order of magnitude
more energy per molecule than you get out of TNT and PETN. I really
didn't want to blast my experimental apparatus to smithereens.

When I went through the calculations with my supervisor, he pulled a
very long face - the motivation for the experiment had been some
unexpected flashes of light seen when a dumb organic chemist had
released small drops of liquid "Dewar benzene" into a hot cell, and my
calculations made it clear that the flashes of light were just thermal
radiation from a hot plasma, rather than fluorsecence from from an
electronically excited state of Kekule benezene, which is what my
supervisor had been hoping for ...

For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

-------
Bill Sloman, Nijmegen

John Michael Williams says...

Guy Macon http://www.guymacon.com wrote...

See my post titled Intrinsic Safety

I did. Thanks.

It appears that the laws involved pertain to manufacturers
and commercial operations. So, I think none would
govern use of a cell phone while gassing up.

I agree. If Intrinsic Safety rules were applied, automobiles
would be banned from gasoline stations. This would not only
eliminate the 35 refueling fires that occur every year, but
would also eliminate most of the 50,000 traffic accident
fatalities...


--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

I read in sci.electronics.design that Bill Sloman
wrote (in ) about 'CB
Radios, Cellphones and Gasoline Vapor Ignition', on Sun, 21 Mar 2004:
For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

Dewar benzene can actually be made? Do you know when it was discovered?
What about the prismatic form? I would have thought that was a lot
easier to make, if I didn't have a suspicion that that is where simple
bonding ideas break down.

--
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

On Sun, 21 Mar 2004 08:47:34 +0000, John Woodgate
wrote:

I read in sci.electronics.design that Jeff Liebermann
wrote (in mppp50ho4dr08ahkb3dlbqkcfkp0ih
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches Kinda small, but given a microscope,
a 1 mil spark gap will arc.

But it takes about 350 V to do so. The relationship between voltage and
gap length is very non-linear below about 500 V.

I didn't know that it wasn't linear. I just assumed that it takes the
same amount of energy to peel electrons off of a single atom (ionize)
regardless of gap seperation. A wider gap requires more voltage to
ionize more atoms to create a longer conduction path, but the energy
per atom is the same. I also couldn't find (Google) any useful
references that showed this non-linearity. Unless the heat generated
by the ionization contributes to assisting furthur ionization, my
seat-o-de-pants physics says it should be linear (for DC).

There's also the minor detail of RF excitation versus DC. As I
vaguely remember from my 35 years ago college welding classes, TIG
welding uses RF to strike the arc because it takes less
power/energy/whatever to start the arc. We're allegedly talking about
striking an arc across 0.001" with a 5 watt, 27MHz transmitter
terminated with a 50 ohm load. If it's non-linear in the opposite
direction, the calcs are gonna be no fun.

I have everything it takes to test this. Microscope slide, with two
sewing pins glued with hotmelt goo and seperated by 0.001". Apply RF
and watch through the microscope. I'll see if I can throw something
together and post photos (time permitting).

Also, I've always been tempted to build a low power, QRP spark gap
transmitter. Although the mode is illegal, I suspect that operating
spark at below Part 15 incidental emission standards, would be
tolerated. Getting the arc to start at such low power levels might
require some exotics (i.e. piezoelectrics). This could be the start
of something interesting (or disgusting).


--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
(831)421-6491 pgr (831)336-2558 home
http://www.LearnByDestroying.com AE6KS

John Woodgate wrote in message ...
I read in sci.electronics.design that Jeff Liebermann
wrote (in mppp50ho4dr08ahkb3dlbqkcfkp0ih
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches Kinda small, but given a microscope,
a 1 mil spark gap will arc.

But it takes about 350 V to do so. The relationship between voltage and
gap length is very non-linear below about 500 V.

In fact the Paschen curve - breakdown voltage plotted against gap -
has a minimum at around a couple of hundred volts, and the breakdown
voltage starts rising again for very small gaps. The linear right-hand
branch of the graph where you might see a slope of 20,000V per inch
doesn't extend down to 22V.

The theory explaining the conductivity of electricity through gases
was worked out around the turn of the last century, and doesn't seem
to be all that well known any more. Pity.

-------
Bill Sloman, Nijmegen

KLM wrote:

On Thu, 18 Mar 2004 05:39:21 +0000, Tim Auton
tim.auton@uton.[groupSexWithoutTheY] wrote:


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.



To use the unique cellphone ID to detonate a remote bomb is actually
a very ingenious innovation. No timers to mess with. The terrorist
has full and instant control of the time and place to set off the
bomb.

As Tim says its relatively easy to connect the ringer wires to a
simple circuit to output enough juice to trigger the detonator. Frist
year student project - like using a battery to keep a capacitor
charged and the ringer closes the discharge switch. Boom.

I'm pretty sure that it won't work that simple. There are other
factors at play that make controlling things with a telephone a lot
harder to achieve than you think... For everyone's safety I'm not
going into the details.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

If you think it is that hard, it's obvious the reason you won't go into the
details. You don't know.
It is rather easily done.

"Nico Coesel" wrote in message
...
I'm pretty sure that it won't work that simple. There are other
factors at play that make controlling things with a telephone a lot
harder to achieve than you think... For everyone's safety I'm not
going into the details.

I read in sci.electronics.design that Jeff Liebermann
wrote (in c1tr509eqipks7lt08ttt5cvnpkumu
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
I didn't know that it wasn't linear.


Google for Paschen's Law. For high voltages it is linear enough for
calibrated spark gaps to be used as voltmeters in the past. The high-
voltage terminals were open and accessible, giving a whole new meaning
to the phrase 'Paschen killers'.(;-)
--
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

John Woodgate wrote in message ...
I read in sci.electronics.design that Bill Sloman
wrote (in ) about 'CB
Radios, Cellphones and Gasoline Vapor Ignition', on Sun, 21 Mar 2004:
For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

Dewar benzene can actually be made? Do you know when it was discovered?
What about the prismatic form? I would have thought that was a lot
easier to make, if I didn't have a suspicion that that is where simple
bonding ideas break down.

IIRR all three Dewar benzenes can be made - with difficulty.

They've been available since before 1971 at least - which is when my
project fell apart - but they were newish then.

The three-carbon rings at either end of the prismatic version do have
a lot of steric strain, but they can be made - I think pyrethroid
insecticides include just such a cyclopropane ring.

----------
Bill Sloman, Nijmegen

CW says...

"Nico Coesel" wrote...

I'm pretty sure that it won't work that simple. There are other
factors at play that make controlling things with a telephone a lot
harder to achieve than you think... For everyone's safety I'm not
going into the details.

If you think it is that hard, it's obvious the reason you won't go into the
details. You don't know.
It is rather easily done.

Any electronics engineer or technician can do it.

(CW, please don't top post)


--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

In , Jeff Liebermann wrote
in part:

Neon lamp needs about 60 volts to light and 40 volts to stay lit. The
4 watt flourescent tube wants at least 90 volts to start, and I think
(i.e. guess) about 50 volts to stay lit.

Lower voltage neon lamps do indeed light at 60 volts RMS and stay lit at
40 volts RMS. But these are lowish figures.

4-watt fluorescents need more, except they stay lit at only about 30
volts at full current, and part of that reason is thermionic emission from
hot electrodes.

I would not worry about RF from a cellphone igniting anything. If a
cellphone is going to be found to ignite gasoline vapor, I think more
likely ways a

* Sparks in the vibration motor
* Sparks from failing wires/connections
* Sparks in speakers with voice coils with intermittent shorts
* Sparks in switches (in whatever few models having switches that
actually switch enough current to make a spark)

I have already seen the Snopes item months ago when I first heard of
cellphones supposedly causing gas station fires, and they make it sound
as if cellphone ignition of gasoline vapors may never have actually
occurred, evidence that this has indeed happened appears mainly anecdotal,
and that this is rare if it does happen.

When I refuel my car, I keep my cellphone either far or upwind from the
gas inlet of my car. (My cellphone has vibration on.) I also ground
myself by touching something far/upwind of the fuel inlet if I let go of
the nozzle and have to touch the nozzle or anything near the fuel inlet
again before leaving the gas station to avoid the greater danger of static
electricity.

- Don Klipstein )

In , Bill Sloman wrote
in part:

I had to work through the equations many years ago for an experiment
intended to monitor the process in which one of the "Dewar benzenes"
converted itself to normal - Kekule's - benzene, which is an
enormously energetic process, involving about an order of magnitude
more energy per molecule than you get out of TNT and PETN. I really
didn't want to blast my experimental apparatus to smithereens.

When I went through the calculations with my supervisor, he pulled a
very long face - the motivation for the experiment had been some
unexpected flashes of light seen when a dumb organic chemist had
released small drops of liquid "Dewar benzene" into a hot cell, and my
calculations made it clear that the flashes of light were just thermal
radiation from a hot plasma, rather than fluorsecence from from an
electronically excited state of Kekule benezene, which is what my
supervisor had been hoping for ...

For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

If this produces anything near 10x the energy per weight of TNT or PETN,
then a version with controlled reaction rate would make one heck of a
rocket propellant.

I thought the ultimate energy per mass was magnesium and oxygen (or was
it beryllium and oxygen?), just a few times as much energy per mass as TNT
and not good like usual rocket propellants for producing gas to use as
rocket exhaust.

I am surely skeptical of changing one isomer of a molecule to another
producing even comparable energy to, let alone more energy than
decomposition of a similar or somewhat greater mass molecule of high
explosive.

- Don Klipstein )

In , Jeff Liebermann wrote:
On Sun, 21 Mar 2004 08:47:34 +0000, John Woodgate
wrote:

I read in sci.electronics.design that Jeff Liebermann
wrote (in mppp50ho4dr08ahkb3dlbqkcfkp0ih
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches Kinda small, but given a microscope,
a 1 mil spark gap will arc.

But it takes about 350 V to do so. The relationship between voltage and
gap length is very non-linear below about 500 V.

I didn't know that it wasn't linear. I just assumed that it takes the
same amount of energy to peel electrons off of a single atom (ionize)
regardless of gap seperation.

It gets messy. You can see how messy it gets when you see what happens
in the cathode area of a "glow discharge".

A "glow discharge" is one of two common processes where positive ions of
the gas/vapor are accelerated by the cathode-adjacent electric field into
the cathode material, and where positive ions bombarding the cathode
dislodge electrons from the cathode to maintain the supply of free
electrons in the "discharge" (conductive path of glowing gas/vapor).
(The other of the two common discharge mechanisms where cathode
bombardment by positive ions dislodges electrons is the "cold cathode
arc". There is still another cathode process for a discharge known as the
"thermionic arc".)

The glow discharge cathode process has 5 layers, 3 dim/dark and 2
bright. There is some sort of 'natural spacing' and 'natural thickness'
of these layers, which varies with gas/vapor type and pressure and the
cathode material. There is also a characteristic voltage drop of the
cathode process known as the "cathode fall", and that is normally a few
times or several times the ionization potential of the gas/vapor.

There is such a thing as "normal glow", where the cathode process occurs
at its natural current density (for the gas/vapor type and pressure and
cathode material), and the first two dark layers and the two bright layers
and some minimal portion of the third dark layer have a tendency to occupy
some 'natural distance' (a function of gas/vapor type and pressure
and cathode material) between cathode and anode.

Then there is "abnormal glow", where the cathode process is forced into
a smaller space between electrodes and/or is conducting a current density
higher than 'natural' (for the gas/vapor type/pressure and cathode
material) due to more current flowing than is "natural" for the available
cross section of cathode process. When that happens, the "cathode fall"
is even higher than that of "nowmal glow".

There's also the minor detail of RF excitation versus DC. As I
vaguely remember from my 35 years ago college welding classes, TIG
welding uses RF to strike the arc because it takes less
power/energy/whatever to start the arc.

I don't know about that, but I have heard of RF glow discharges maybe
having the cathode process eliminating one bright layer and one dark layer
(for "electrodeless discharge" that occurs where insulation exists over
the cathode for example), and that may reduce the cathode fall.

We're allegedly talking about
striking an arc across 0.001" with a 5 watt, 27MHz transmitter
terminated with a 50 ohm load. If it's non-linear in the opposite
direction, the calcs are gonna be no fun.

:) at best!!!

I have everything it takes to test this. Microscope slide, with two
sewing pins glued with hotmelt goo and seperated by 0.001". Apply RF
and watch through the microscope. I'll see if I can throw something
together and post photos (time permitting).

Please do!!!

- Don Klipstein )

"S" wrote in message et...
the show on discovery channel, mythbusters. debunked that myth,


They also showed in the same episode that a good percentage of
fueling fires come from static sparks around the gas tank. Someone
mentioned it before, but ground yourself away from the tank before you
start fueling. Apparently women are more likely not to ground
themselves and have something 70% of all spark induced fires. It was
pretty cool to watch the show and see a firefighter deliberately
generate a static spark and light himself on fire at a gas pump.

Jeff Liebermann wrote in message . ..
On Sun, 21 Mar 2004 08:47:34 +0000, John Woodgate
wrote:

I read in sci.electronics.design that Jeff Liebermann
wrote (in mppp50ho4dr08ahkb3dlbqkcfkp0ih
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
The gap necessary to create an arc with 22 volts is:
22V / 20,000V/in = 0.001 inches Kinda small, but given a microscope,
a 1 mil spark gap will arc.

But it takes about 350 V to do so. The relationship between voltage and
gap length is very non-linear below about 500 V.

I didn't know that it wasn't linear. I just assumed that it takes the
same amount of energy to peel electrons off of a single atom (ionize)
regardless of gap seperation. A wider gap requires more voltage to
ionize more atoms to create a longer conduction path, but the energy
per atom is the same. I also couldn't find (Google) any useful
references that showed this non-linearity. Unless the heat generated
by the ionization contributes to assisting furthur ionization, my
seat-o-de-pants physics says it should be linear (for DC).

You need to read up on the physics involved. The critical point is
that a free electron in the gas has to have a long enough mean free
path to pick up enough energy by falling down the electric field to be
able to ionise a molecule when it does hit one, generating one more
electron in an inelastic collision.

If it hits a molecule before it acquires enough energy, in an elastic
collision, it will end up travelling in a different direction with the
same energy, but with a good chance of losing the energy that it had
accumulated. Think "drunkards walk".

The minimum in the Paschen curve corresponds to the point where the
mean free path is longer than the gap.

There's also the minor detail of RF excitation versus DC. As I
vaguely remember from my 35 years ago college welding classes, TIG
welding uses RF to strike the arc because it takes less
power/energy/whatever to start the arc. We're allegedly talking about
striking an arc across 0.001" with a 5 watt, 27MHz transmitter
terminated with a 50 ohm load. If it's non-linear in the opposite
direction, the calcs are gonna be no fun.

RF excitation works better than DC becasue it doesn't sweep the
electrons out of the gap as they are created (by cosmic rays or local
radioactivity) in the way that a DC field does. Like I said earlier,
the physics was worked out about a hundred years ago, and the
calculations shouldn't be too difficult now that we can use computers
for the tedious bits.

I have everything it takes to test this. Microscope slide, with two
sewing pins glued with hotmelt goo and seperated by 0.001". Apply RF
and watch through the microscope. I'll see if I can throw something
together and post photos (time permitting).

Everything except a sound undertanding of the theory. I've got a copy
of a reprint of volume 2 of "Conduction of Electricity Through Gases"
- Ionisation byCollision and the Gaseous Discharge - by J.J. Thompson
and G.P. Thompson.
My copy was published by Dover Press in 1969, and reprints the 1933
third edition. The first - singe volume - edition was published in
1903. I bought it when I was fiddling around building a starter for a
xenon arc lamp, back in 1972. It proved quite useful.

-------
Bill Sloman, Nijmegen

On Sun, 21 Mar 2004 23:00:47 +0000, John Woodgate
wrote:

I read in sci.electronics.design that Jeff Liebermann
wrote (in c1tr509eqipks7lt08ttt5cvnpkumu
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
I didn't know that it wasn't linear.

Google for Paschen's Law. For high voltages it is linear enough for
calibrated spark gaps to be used as voltmeters in the past. The high-
voltage terminals were open and accessible, giving a whole new meaning
to the phrase 'Paschen killers'.(;-)

Yep. That's it. Thanks. Haven't seen that since kollege. Also saw
your comments on the topic in other usenet news articles. So much for
my simplified view of ionization.

Online spark gap calculator:
http://www.cirris.com/testing/voltage/arc.html

Minimum breakdown voltage in air at STP is about 350VDC. For RF, that
would be:
350 * 0.707 = 192 Vrms
Into a 50 ohm antenna at the coax connector,
P = E^2 / R = 192 * 192 / 50 = 737 watts
for any size spark gap. I don't know of any kilowatt cell phones
around, but that's the power output needed to arc at the antenna
connector. It might be somewhat lower due to the effects of RF vs DC.
Also a suitably weird antenna could be fabricated to dramatically
increase the voltage at some point. However, those coils are usually
up in the air where they cannot get close to a ground suitable for
forming a spark gap.


--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
(831)421-6491 pgr (831)336-2558 home
http://www.LearnByDestroying.com AE6KS

Jeff Liebermann says...

John Woodgate wrote:

Google for Paschen's Law. For high voltages it is linear enough for
calibrated spark gaps to be used as voltmeters in the past. The high-
voltage terminals were open and accessible, giving a whole new meaning
to the phrase 'Paschen killers'.(;-)

Yep. That's it. Thanks. Haven't seen that since kollege. Also saw
your comments on the topic in other usenet news articles. So much for
my simplified view of ionization.

I am removing Mr. Woodgate from my killfile. I was under the
impression that he only wanted to post about politics in the wrong
newsgroup, but obviously I was wrong. My apologies to Mr. Woodgate.


--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

"Nico Coesel" wrote in message
...

I'm pretty sure that it won't work that simple. There are other
factors at play that make controlling things with a telephone a lot
harder to achieve than you think... For everyone's safety I'm not
going into the details.

You could, only there are no details.

Using a ringer's voltage levels is indeed easy, there is really nothing to
hide because every EE student can figure out the details for himself. Let's
use an example. Since I'm not a terrorist, I assume that the circuit is used
to light a lamp as an aid for a hearing-impaired person who could than turn
on his hearing aid in case it was off, and do not encourage anyone to put
anything else in place of that lamp. To make it even less usable for certain
people, the following example relies on the ringer NOT being removed from
the circuit so it would ring (this way an additional time delay cannot be
used). The amplifying of the ringer signal can be done with only one
transistor, the voltage offsets be provided with a normal and a shottky
diode. Let's also assume that the ringer is a dynamic and not a
piezoelectric one, since with a piezo the circuit would differ slightly. A
reed relay could do the switching. Using an NPN, the circuit would look like
this: Negative ground, connected with ringer's "-", to battery "-" and
through a forward-biased shottky to the emitter. The transistor's base
connected through a 2K2 resistor to battery "+". Base also connected to
diode "+", while diode "-" is connected to ringer "+". Collector through
relay coil to battery "+", a capacitor across the relay coil. That's it. The
relay contacts can be used to switch on a lamp, connected to the same
battery and placed so that the hearing-impaired person can easily see it.
Note to hearing-impaired preople: this circuit may not always work, it
depends on the type of ringer and on the volume setting. I did not test it
with any ringers either, but I think many old-style ones should do.

(Don Klipstein) wrote in message ...
In , Bill Sloman wrote
in part:

I had to work through the equations many years ago for an experiment
intended to monitor the process in which one of the "Dewar benzenes"
converted itself to normal - Kekule's - benzene, which is an
enormously energetic process, involving about an order of magnitude
more energy per molecule than you get out of TNT and PETN. I really
didn't want to blast my experimental apparatus to smithereens.

When I went through the calculations with my supervisor, he pulled a
very long face - the motivation for the experiment had been some
unexpected flashes of light seen when a dumb organic chemist had
released small drops of liquid "Dewar benzene" into a hot cell, and my
calculations made it clear that the flashes of light were just thermal
radiation from a hot plasma, rather than fluorsecence from from an
electronically excited state of Kekule benezene, which is what my
supervisor had been hoping for ...

For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

If this produces anything near 10x the energy per weight of TNT or PETN,
then a version with controlled reaction rate would make one heck of a
rocket propellant.

I thought the ultimate energy per mass was magnesium and oxygen (or was
it beryllium and oxygen?), just a few times as much energy per mass as TNT
and not good like usual rocket propellants for producing gas to use as
rocket exhaust.

It depends on the electrochemical gradient, I think.
Hydrogen burning in fluorine probably produces more combustion
energy than anything else, per unit mass.


I am surely skeptical of changing one isomer of a molecule to another
producing even comparable energy to, let alone more energy than
decomposition of a similar or somewhat greater mass molecule of high
explosive.

I share this skepticism. Burning TNT probably would produce 10x more
free energy than detonating it.



John

John Michael Williams

Jeff Liebermann wrote in message . ..
On Sun, 21 Mar 2004 23:00:47 +0000, John Woodgate
wrote:

I read in sci.electronics.design that Jeff Liebermann
wrote (in c1tr509eqipks7lt08ttt5cvnpkumu
) about 'CB Radios, Cellphones and Gasoline Vapor
Ignition', on Sun, 21 Mar 2004:
I didn't know that it wasn't linear.

Google for Paschen's Law. For high voltages it is linear enough for
calibrated spark gaps to be used as voltmeters in the past. The high-
voltage terminals were open and accessible, giving a whole new meaning
to the phrase 'Paschen killers'.(;-)

Yep. That's it. Thanks. Haven't seen that since kollege. Also saw
your comments on the topic in other usenet news articles. So much for
my simplified view of ionization.

Online spark gap calculator:
http://www.cirris.com/testing/voltage/arc.html

Minimum breakdown voltage in air at STP is about 350VDC. For RF, that
would be:
350 * 0.707 = 192 Vrms
Into a 50 ohm antenna at the coax connector,
P = E^2 / R = 192 * 192 / 50 = 737 watts
for any size spark gap. I don't know of any kilowatt cell phones

Then again, some users seem to be able to put in kilohours of talk.
Does that count? (just kidding).

Seriously, into air at the antenna,

P = E^2/377 ~= 97 W.

A very sharp tip would create an additional gradient,
which suggests trying to spark with a sharpened antenna against
something metallic at AC ground.


around, but that's the power output needed to arc at the antenna
connector. It might be somewhat lower due to the effects of RF vs DC.
Also a suitably weird antenna could be fabricated to dramatically
increase the voltage at some point. However, those coils are usually
up in the air where they cannot get close to a ground suitable for
forming a spark gap.

John

John Michael Williams

(John Michael Williams) wrote in message . com...
(Don Klipstein) wrote in message ...
In , Bill Sloman wrote
in part:

I had to work through the equations many years ago for an experiment
intended to monitor the process in which one of the "Dewar benzenes"
converted itself to normal - Kekule's - benzene, which is an
enormously energetic process, involving about an order of magnitude
more energy per molecule than you get out of TNT and PETN. I really
didn't want to blast my experimental apparatus to smithereens.

When I went through the calculations with my supervisor, he pulled a
very long face - the motivation for the experiment had been some
unexpected flashes of light seen when a dumb organic chemist had
released small drops of liquid "Dewar benzene" into a hot cell, and my
calculations made it clear that the flashes of light were just thermal
radiation from a hot plasma, rather than fluorsecence from from an
electronically excited state of Kekule benezene, which is what my
supervisor had been hoping for ...

For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

If this produces anything near 10x the energy per weight of TNT or PETN,
then a version with controlled reaction rate would make one heck of a
rocket propellant.

Not really. The crucial feature of chemical explosives is that they
produce their energy fast, which is to say by intra-molecular
rearrangement. Burning a hydrocarbon in oxygen produces a lot more
energy per unit mass of fuel and oxidiser than does letting off TNT or
PETN where the oxygen comes from the nitro groups attached to the
hydrocarbon core, whence the popularity of fuel-air bombs, but you
don't get the same brissance.

I thought the ultimate energy per mass was magnesium and oxygen (or was
it beryllium and oxygen?), just a few times as much energy per mass as TNT
and not good like usual rocket propellants for producing gas to use as
rocket exhaust.

It depends on the electrochemical gradient, I think.
Hydrogen burning in fluorine probably produces more combustion
energy than anything else, per unit mass.

Atomic hydrogen recombining into molecular hydrogen would be better
(as a rocket fuel) but has never been reduced to practice. What I
remember from what I read on the subject - many years ago - was that
hydrogen-fluorine was the best possible fuel-oxidiser combination.
Nasty exhaust fumes ...

I am surely skeptical of changing one isomer of a molecule to another
producing even comparable energy to, let alone more energy than
decomposition of a similar or somewhat greater mass molecule of high
explosive.

Check out the published literature - that is all that I was doing at
the time.
Chemical explosives are relatively wimpy as far as energy per unit
mass goes - the rate of energy release is the crucial feature.

I share this skepticism. Burning TNT probably would produce 10x more
free energy than detonating it.

Trinitrotoluene is C7H5N3O6 and would burn to 7 CO2 molecules, 2.5 H2O
molecules and 1.5 N2 molecules - for which you'd need 10.5 extra
oxygen atoms, over and above the six oxygen atoms available in the
original TNT molecule.

Being simple-minded about it, 16.5/6 is 2.75, not ten, and that
exaggerates the advantage, because burning carbon to carbon monoxide
release quite a lot more energy than burning carbon monoxide to carbon
dioxide, which is where you use up seven of your extra 10.5 oxygen
atoms.

The exact amounts of energy involved are all available in the open
literature - that is where I found them, some thirty years ago, and
I'm sure that they are still available now.

-------
Bill Sloman, Nijmegen

In article , John
Michael Williams wrote:
(Don Klipstein) wrote in message ...
In , Bill Sloman wrote
in part:

I had to work through the equations many years ago for an experiment
intended to monitor the process in which one of the "Dewar benzenes"
converted itself to normal - Kekule's - benzene, which is an
enormously energetic process, involving about an order of magnitude
more energy per molecule than you get out of TNT and PETN. I really
didn't want to blast my experimental apparatus to smithereens.

When I went through the calculations with my supervisor, he pulled a
very long face - the motivation for the experiment had been some
unexpected flashes of light seen when a dumb organic chemist had
released small drops of liquid "Dewar benzene" into a hot cell, and my
calculations made it clear that the flashes of light were just thermal
radiation from a hot plasma, rather than fluorsecence from from an
electronically excited state of Kekule benezene, which is what my
supervisor had been hoping for ...

For the difference between Dewar benzene and Kekule benzene see

http://www.chemsoc.org/exemplarchem/...enzenering.htm

If this produces anything near 10x the energy per weight of TNT or PETN,
then a version with controlled reaction rate would make one heck of a
rocket propellant.

I thought the ultimate energy per mass was magnesium and oxygen (or was
it beryllium and oxygen?), just a few times as much energy per mass as TNT
and not good like usual rocket propellants for producing gas to use as
rocket exhaust.

It depends on the electrochemical gradient, I think.
Hydrogen burning in fluorine probably produces more combustion
energy than anything else, per unit mass.

That one is up there, but let's check heat of formation...

HF gas: 63.991 KCal/mole, 3.19955 KCal/gram

MgO: 145.76 KCal/mole, 3.644 KCal/gram, but with no gaseous output.

I am surely skeptical of changing one isomer of a molecule to another
producing even comparable energy to, let alone more energy than
decomposition of a similar or somewhat greater mass molecule of high
explosive.

I share this skepticism. Burning TNT probably would produce 10x more
free energy than detonating it.

The usual high explosives contain nitrate or nitro-group molecule
portions, or other oxidizers.

TNT does not have enough oxygen in its nitro groups for complete
combustion, so you get some more energy burning it than detonating it.
On the other hand, nitroglycerin and RDX have enough oxygen in their
nitrate groups for complete combustion.

- Don Klipstein )

John Michael Williams wrote:
I share this skepticism. Burning TNT probably would produce 10x more
free energy than detonating it.

When you detonate it, what happens to the 90% lost energy?
Fails to actually detonate?
--
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! =-----

In article ,
DarkMatter TheBartenderBuyMeADrink wrote:

First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

High explosives certainly can burn - burning and detonation are
physically different processes.

I remember reading stories of demolition-team soldiers in Vietnam,
heating their rations by taking a small pellet of C-4 plastic
explosive (RDX) and igniting it. It makes a hot flame, quite
sufficient to toast up the C-rations, and does not explode. [Not a
terribly good substitute for a real camp stove, though, as C-4
produces toxic fumes when burned.]

Burning is, in fact, the standard way for the military to dispose of
C-4 from unwanted munitions.

It appears that burning is also a viable method of destroying TNT.
http://www.humanitarian-demining.org...tral/remic.asp
describes a method for destroying land mines "in situ" via burning.
It's a neat trick - a small shaped charge of explosive creates a
high-velocity gas jet which breaks open the (TNT-loaded) land mine,
and also delivers a charge of a pyrogenic chemical which ignites and
burns the TNT without detonating it.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

DarkMatter wrote:
First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

If one arranged the TNT into a fuse, how fast would it burn?
--
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! =-----

I read in sci.electronics.design that Don Klipstein
wrote (in ) about 'CB Radios,
Cellphones and Gasoline Vapor Ignition', on Tue, 23 Mar 2004:
That one is up there, but let's check heat of formation...

HF gas: 63.991 KCal/mole, 3.19955 KCal/gram

MgO: 145.76 KCal/mole, 3.644 KCal/gram, but with no gaseous output.

Do you have the figures for CsF?

DON'T TRY THIS AT HOME.(;-)
--
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

I read in sci.electronics.design that Cecil Moore
EDOT.org wrote (in ) about 'CB Radios,
Cellphones and Gasoline Vapor Ignition', on Tue, 23 Mar 2004:
John Michael Williams wrote:
I share this skepticism. Burning TNT probably would produce 10x more
free energy than detonating it.

When you detonate it, what happens to the 90% lost energy?
Fails to actually detonate?

Sort of. Bill S more or less explained it further up the thread. When it
detonates, it all happens so quickly that only it's on-board oxygen (in
the nitrate groups) is available. So the oxidation is imperfect, and not
all the available energy is released. You get free carbon, carbon
monoxide, oxidized organic residues and nitrogen. When it burns, using
atmospheric oxygen as well, you get carbon dioxide, water and nitrogen -
all the available energy is released.
--
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

In article ,
DarkMatter wrote:

First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

That guy's empty skull cavity has a lot of free space in it.

TNT burns just like Sterno. In WWII and Vietnam TNT was used to cook on
just like the Sterno can's were. It is very stable in this decomasition
mode. One can shot it with rifles while burning and it just continues
to burn. Been there, done that, many times.....

Bruce in alaska who also has decomposed TNT the FAST way as well.....
--
add a 2 before @

On 23-Mar-2004, Bruce in Alaska wrote:

In article ,
DarkMatter wrote:

First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

That guy's empty skull cavity has a lot of free space in it.

TNT burns just like Sterno. In WWII and Vietnam TNT was used to cook on
just like the Sterno can's were. It is very stable in this decomasition
mode. One can shot it with rifles while burning and it just continues
to burn. Been there, done that, many times.....

Bruce in alaska who also has decomposed TNT the FAST way as well.....
--
add a 2 before @

While the thread might be interesting to some readers, and granted that the original topic had
something to do with arcing associated with antennas, the discussion of explosives is very off-topic
for rec.radio.amateur.antenna. It might be appreciated if the cross-posting came to an end.
Thank you.

Cecil Moore wrote:


When you detonate it, what happens to the 90% lost energy?
Fails to actually detonate?

Cecil, we can have fun with this! Isn't the missing energy is exciting
a 1/2 wavelength impedance repeater :-)

DarkMatter says...

First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

You are thinking of low explosives (gunpowder is a good example).
Low explosives burn rapidly - fast enough to explode if confined.
High explosives are detonated as a shock wave propagates through
them, as opposed to low explosives which are detonated as a flame
front propagates through them, There is no reason why one couldn't
burn a high explosive and get a low burning rate.


--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

Ken Fowler says...

While the thread might be interesting to some readers, and granted that the original topic had
something to do with arcing associated with antennas, the discussion of explosives is very off-topic
for rec.radio.amateur.antenna. It might be appreciated if the cross-posting came to an end.
Thank you.

Point well taken. It's off-topic in sci.electronics.basics as well.
I apologize for participating.


--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

"DarkMatter" wrote in message
...
On Tue, 23 Mar 2004 09:50:00 -0600, Cecil Moore
Gave us:

John Michael Williams wrote:
First, tell me how one "burns TNT". It is a high explosive. I
think its "burn rate" would be pretty fast, and not manageable.

I've heard more than one ex-Grunt talk about burning C3 to
warm his army chow. Apparently it burns slow without a detonator.
Don't know if trinitrotoluene (hope I spelled it right) can be used
that way.

HWB