Radar detection

[speccysid]

Anyone know which bands are used by the police these days for speed detection other than lasers cos i am trying to filter out a mates detector to not include unused bands like the K band that the traffic lights use that make the thing go mental.
It can detect
9.41ghz X band, 9.9ghz X band, 10.525ghz X band, 10.600ghz X band.
13.45ghz Ku band, 24.125ghz K band, 24.150ghz K band, 34.0ghz Ka smal band,34.3ghz Ka smal-band, 34.7ghz Ka smalband and 33.4 tot 36.0 Ka super wide band and 904 nanometre laser.
So anyone know which are obsolete?
Thx

[Ventral]

Isn't this illegal? :roll:

[[n00b]SteveO]

nope

[speccysid]

It never has been illegal. They clarified the rules in 1998 so people would know that it is not illegal to use them and in fact never has been.

[[n00b]SteveO]

Ive got a road angel and ive taken off the laser detector, it drives me crackers when it starts bleeping as i pass a petrol station :/

[speccysid]

yeh why is it petrol stations set them off?

[Flossie]

yeh why is it petrol stations set them off?

dunno, but it might be connected with the rumour that the *real* reason they don't like you using mobile phones & radios at petrol pumps and suddenly decided to drag up an ancient law recently is that you can reset the pumps by transmitting near them (hence getting free petrol...)

[nameinuse]

The petrol pump phone thing is that if you get the right conditions(vapour mix and frequency), any RF can set petrol off, (think what microwaves do to water but with the frequency tweaked for octane).

I think you'd probably need a HERF gun or a MASER to reset a petrol pump's electronics, they're usually sheilded too due to the RF put out by alternators and the HT in a car. By the time you'd got to the pump, you'd have melted the person standing next to you or obliterated a 100m radius by setting off some petrol vapour...

[nameinuse]

Oh, and PS, the most likely explaination for petrol stations tripping a radar detector is that they use radar to work out if there's a car to take a picture of when doing numberplate recognition, to stop drive-offs.

[Sid]

The petrol pump phone thing is that if you get the right conditions(vapour mix and frequency), any RF can set petrol

i believe the technical term for this is 'bollocks'

the main reason they don't want you to use your mobile phone is cos you won't be concentrating on putting petrol in and may spill it

secondly, lots of petrol stations have mobile phone masts built into their signs out the front, so it may just cause your mobile issues

there is an extremely small risk that if you have to parallel pieces of metal with a very small air gap, the radio frequency from the mobile could turn them into a capacitor and cause a spark

there is a considerably higher chance of everyone on the forecourt simultaneously winning the lottery and then being struck down by individual meteors

[Jackal]

people tend to forget that cars are essentially spark making machines and theres a much much much much greater chance of an engine spark igniting anything from under the engine than there is from a mobile phone

especially with my dodgy wiring

[Scrobbs]

SteveO]Ive got a road angel and ive taken off the laser detector, it drives me crackers when it starts bleeping as i pass a petrol station :/


ooo! This would be what I would go for if I had the cash. Great little things.

[nameinuse]

The point about RF is it's theoretical, and you'd need a lot of power (I really can't be bothered to work out if 8-divisionl GPRS would be sufficient), and the right frequency, and you'd be able to excite petrol molecules above their flashpoint.

Depending on the molecule involved, there are a few bond types that'll absorb in the region (mostly as resonances of their IR absorbtion, iirc), and they could pick up radiation to flashpoint.

I didn't say it was likely, and it's liable to need a lot of power to do it, too. Last article I read, the danger was thought to be not vapour in the air, but vapour in the tank, where things are designed not to spark (they're plastic or earthed metal for a reason...).

As to the spark theory, yeah, that's true, but they don't mention other electronic devices, but specifically radios (inc. CB radios), and moblile phones.

These rules were written with caution in mind, which is a good thing when dealing with gallons of flammable fluid. As lots of phone makers have proved, the chances of something as low power as a phone causing an explosion in this manner are smaller than tiny. If you had that MASER on the other hand...

[mick3ymous3]

erm...this gone a little off topic hasn't it guys?

sorry i got no idea speccy!