peter berrett wrote:
Hi all

I have been looking at the use of APRS over packet radio and noted that many
Amateurs now have mobile installations in their cars both for fun and to
assist in tracking the vehicle should it get stolen.

This is quite an appealing idea however I do have one concern that I hope an
experienced mobile APRS user could assist me with.

When one visits petrol/gas stations here in Australia one sees signs saying
to switch off one's mobile phone as the electromagnetic radiation could
cause a spark and ignite fuel vapour. It has made me wonder how to make APRS
safe so that should you be filling up your car at a gas station you can be
assured that a regular APRS update from your mobile APRS setup won't run a
risk of causing a fire.

Have APRS users considered this possibility and what precaustions, if any,
are taken to deal with this problem?

cheers Peter


Urban legend.

See http://www.snopes.com/autos/hazards/gasvapor.asp for a full discussion.


--
Jim Pennino

Remove -spam-sux to reply.

Would not even need a laptop; just a Palm to do this.

You could even use a PalmPhone, and add to it a "kill switch" on the
ignition, a flow restictor on the gas (won't go over 10kph) or a "park lock
override" on the transmission (if automatic) which would prevent the
vehicle from getting out of Park.

Would take the fun out of using APRS, but you'd get your car back a lot
faster.

On Mon, 9 Feb 2004 22:42:27 +1100, "peter berrett"
wrote:
snip

Equipment:

1 x old notebook computer with sound card to act as modem
1 x mouse gps - usb connection
1 x 2m ht

The idea is that the ht would sit on 144.900 mhz and listen for aprs
packets. It would however only supply an aprs packet if polled remotely (ie
you have to send it a special code to start transmitting aprs packets)
however so most of the time there is no transmission. If you fill up at a
pretrol station there is no danger because your setup is not transmitting at
all.

Say your car gets stolen. You send a particular code through the aprs system
and tell the notebook computer to start transmitting aprs packets every
minute. You then track the car until the police catch up with it.

Workable but safe?

Very safe. The story about risk at petrol stations form RF has been
disproven as an Urban Legend.

cheers Peter
--
Nobody but a fool goes into a federal counterrorism operation without duct tape - Richard Preston, THE COBRA EVENT.

Would not even need a laptop; just a Palm to do this.

You could even use a PalmPhone, and add to it a "kill switch" on the
ignition, a flow restictor on the gas (won't go over 10kph) or a "park lock
override" on the transmission (if automatic) which would prevent the
vehicle from getting out of Park.

Would take the fun out of using APRS, but you'd get your car back a lot
faster.

On Mon, 9 Feb 2004 22:42:27 +1100, "peter berrett"
wrote:
snip

Equipment:

1 x old notebook computer with sound card to act as modem
1 x mouse gps - usb connection
1 x 2m ht

The idea is that the ht would sit on 144.900 mhz and listen for aprs
packets. It would however only supply an aprs packet if polled remotely (ie
you have to send it a special code to start transmitting aprs packets)
however so most of the time there is no transmission. If you fill up at a
pretrol station there is no danger because your setup is not transmitting at
all.

Say your car gets stolen. You send a particular code through the aprs system
and tell the notebook computer to start transmitting aprs packets every
minute. You then track the car until the police catch up with it.

Workable but safe?

Very safe. The story about risk at petrol stations form RF has been
disproven as an Urban Legend.

cheers Peter
--
Nobody but a fool goes into a federal counterrorism operation without duct tape - Richard Preston, THE COBRA EVENT.

Man, you're in big trouble if the wife knows you're on the Internet
spouting that women give off more static than men!

On 09 Feb 2004 14:08:55 GMT, (AA) wrote:

Then switch it off before you go into the filling station.
And how close to the tanks could one be without switching off?
How about passing the station on the street, possibly with the tank vent
pipes between the street (i.e. yourself) and the pumps?

The major problem you'd have is static electricity. RF will pose no problem in
the normal amounts emitted by a standard mobile rig (i.e., 5-50 wts). The
ignition method most commonly seen is static buildup, person does not discharge
against the car body before touching the nozzle (grounded to the pump via the
hose...it has a wire mesh and/or grounding wire built into it). Nice spark
results, as does ignition of the vapors. One thing that was noted....women
are more likely to have this happen...best guess is due to two reasons. One,
material in clothing may be higher in static-generating capability. Second, on
cold days, women tend to return to the car and wait for the tank to fill. When
they get out, they're a nice static source looking for a ground. The nozzle
provides that.

As for RF, we used to use an old Clegg FM27B to test the electronics (faraday
chamber)....never had any fuel ignition problems, and the lockup problems were
mostly due to ground loop situations which were resonant on some more commonly
used frequency, such as 400 mhz +/-. Drove one prototype unit nuts until the
chief engineer (also a ham) happened to key his 70cm rig when sitting by the
unit. Turns out the local police liked the donuts sold at the station......

A
(ex-R&D/Sales at a pump company)


Spammers, please send email to:

and get your SMTP server blacklisted!

Man, you're in big trouble if the wife knows you're on the Internet
spouting that women give off more static than men!

On 09 Feb 2004 14:08:55 GMT, (AA) wrote:

Then switch it off before you go into the filling station.
And how close to the tanks could one be without switching off?
How about passing the station on the street, possibly with the tank vent
pipes between the street (i.e. yourself) and the pumps?

The major problem you'd have is static electricity. RF will pose no problem in
the normal amounts emitted by a standard mobile rig (i.e., 5-50 wts). The
ignition method most commonly seen is static buildup, person does not discharge
against the car body before touching the nozzle (grounded to the pump via the
hose...it has a wire mesh and/or grounding wire built into it). Nice spark
results, as does ignition of the vapors. One thing that was noted....women
are more likely to have this happen...best guess is due to two reasons. One,
material in clothing may be higher in static-generating capability. Second, on
cold days, women tend to return to the car and wait for the tank to fill. When
they get out, they're a nice static source looking for a ground. The nozzle
provides that.

As for RF, we used to use an old Clegg FM27B to test the electronics (faraday
chamber)....never had any fuel ignition problems, and the lockup problems were
mostly due to ground loop situations which were resonant on some more commonly
used frequency, such as 400 mhz +/-. Drove one prototype unit nuts until the
chief engineer (also a ham) happened to key his 70cm rig when sitting by the
unit. Turns out the local police liked the donuts sold at the station......

A
(ex-R&D/Sales at a pump company)


Spammers, please send email to:

and get your SMTP server blacklisted!

I agree with the comment at the end. I'm no lawyer, but what about
the liability you have by activating a transmitter in a stolen car and
blowing up the thief and a gas station?

Are there laws against booby-trapping cars?

On Tue, 10 Feb 2004 18:45:41 GMT, Jim Higgins wrote:

On Mon, 9 Feb 2004 22:42:27 +1100, in
, "peter berrett"
wrote:

Hi again

It looks like I've started World War III with this topic.

I think it is a shame that some are glossing over the topic because safety
with petroleum is a serious issue. Maybe APRS does not pose a hazard but the
topic deserves serious discussion.

Perhaps... but except for a few who have done some research and
posted that the original premise was nothing but an urban legend
to begin with, the most it's getting here is speculation.

[snip]

Say your car gets stolen. You send a particular code through the aprs system
and tell the notebook computer to start transmitting aprs packets every
minute. You then track the car until the police catch up with it.

Workable but safe?

Pretending for a moment the original premise is true... what
happens if the thief decides to gas up the stolen car? I don't
think this solution shows proper safety consideration for all the
children that might be killed by it. ;-)

Spammers, please send email to:

and get your SMTP server blacklisted!

I agree with the comment at the end. I'm no lawyer, but what about
the liability you have by activating a transmitter in a stolen car and
blowing up the thief and a gas station?

Are there laws against booby-trapping cars?

On Tue, 10 Feb 2004 18:45:41 GMT, Jim Higgins wrote:

On Mon, 9 Feb 2004 22:42:27 +1100, in
, "peter berrett"
wrote:

Hi again

It looks like I've started World War III with this topic.

I think it is a shame that some are glossing over the topic because safety
with petroleum is a serious issue. Maybe APRS does not pose a hazard but the
topic deserves serious discussion.

Perhaps... but except for a few who have done some research and
posted that the original premise was nothing but an urban legend
to begin with, the most it's getting here is speculation.

[snip]

Say your car gets stolen. You send a particular code through the aprs system
and tell the notebook computer to start transmitting aprs packets every
minute. You then track the car until the police catch up with it.

Workable but safe?

Pretending for a moment the original premise is true... what
happens if the thief decides to gas up the stolen car? I don't
think this solution shows proper safety consideration for all the
children that might be killed by it. ;-)

Spammers, please send email to:

and get your SMTP server blacklisted!

"DxxxxxBxx" wrote in message
...


Are there laws against booby-trapping cars?


No, we have had women drivers for years, now.

Charles, N5PVL

"DxxxxxBxx" wrote in message
...


Are there laws against booby-trapping cars?


No, we have had women drivers for years, now.

Charles, N5PVL

Last year my car was stolen in St Kilda and was found 6 months later parked
about 10 blocks east of where it was stolen. An APRS system would have been
very useful.

I also dream about somebody stealing my car so I use APRS to track where it
is and advise the Police. Then when they give me the signal I kill the
engine by remote control and possibly have a digital camera installed in the
car to photograph the driver.

:)

Could be fun. I'd almost want someone to steal my car!

cheers Peter






wrote in message
...
Would not even need a laptop; just a Palm to do this.

You could even use a PalmPhone, and add to it a "kill switch" on the
ignition, a flow restictor on the gas (won't go over 10kph) or a "park
lock
override" on the transmission (if automatic) which would prevent the
vehicle from getting out of Park.

Would take the fun out of using APRS, but you'd get your car back a lot
faster.

On Mon, 9 Feb 2004 22:42:27 +1100, "peter berrett"
wrote:
snip

Equipment:

1 x old notebook computer with sound card to act as modem
1 x mouse gps - usb connection
1 x 2m ht

The idea is that the ht would sit on 144.900 mhz and listen for aprs
packets. It would however only supply an aprs packet if polled remotely
(ie
you have to send it a special code to start transmitting aprs packets)
however so most of the time there is no transmission. If you fill up at a
pretrol station there is no danger because your setup is not transmitting
at
all.

Say your car gets stolen. You send a particular code through the aprs
system
and tell the notebook computer to start transmitting aprs packets every
minute. You then track the car until the police catch up with it.

Workable but safe?

Very safe. The story about risk at petrol stations form RF has been
disproven as an Urban Legend.

cheers Peter
--
Nobody but a fool goes into a federal counterrorism operation without duct
tape - Richard Preston, THE COBRA EVENT.