radar detectors

[spudchucka]

I'm pretty sure(from what those in the know have told me...spud??)the radar will emit a different tone (length?)when it has a detector reading it.....

Not in my experience. The Hawk / Stalker emits a tone relevant to the speed of the vehicle it is reading. When the tone suddenly shoots upwards its just telling the operator that there is a fast oncoming vehicle. This is only relevant if the unit is transmitting constantly, which isn't the best way to use it.

The tone can be turned off thankfully because the squaking can drive you bonkers sometimes.

[marty]

I'm pretty sure(from what those in the know have told me...spud??)the radar will emit a different tone (length?)when it has a detector reading it.....

the radar tone changes pitch only with signal strength. detectors have no influence.

[Wenier]

the understanding i have of the radars in the police cars is that the tone emitted changes when locked onto a vehicle to wut the driver does. if they lock onto your speed and you brake it is meant to make a tone that gets deeper as u brake so they no u are braking. and opposite of course speed up higher pitch emitted.

Detectors are not illegal but a cop will give you more shit if ya use one. typical question wuts that for, smart answer it gets the chicks, or any or smart arse remark you can think of.

Jammers are not illegal unless being used. therefore you can buy one but are not meant to use it of course they come with a switch to turn it off once down to speed so the cop can get a lock on ya and think he wasnt aiming it at you properly!

[Blackbird]

This may make strange reading at first, but I didn't actually buy the detector to give me the edge on a continuous high speed ride. I'm completely paranoid about overtaking manoeuvres! You know the scenario... catching up to 2 or 3 cars doing about 90k's and no-one wants to overtake, so you knock it down a gear or two to get past as quickly as possible. Trouble is, modern bikes can be going very quickly indeed in a short space of time and I've had a couple of close calls when a cop has either appeared round a corner coming the other way, or has been discreetly buried in a line of traffic coming the other way just as I've been pulling back in. I doubt that a cop would buy the safety benefit angle of a rapid passing manoeuvre, so the detector just gives a bit more assurance. In addition, even a moderate performance detector will pick up a static camera van at a decent distance, and that's a real plus!

[marty]

[QUOTE=Wenier]the understanding i have of the radars in the police cars is that the tone emitted changes when locked onto a vehicle to wut the driver does. if they lock onto your speed and you brake it is meant to make a tone that gets deeper as u brake so they no u are braking. and opposite of course speed up higher pitch emitted.

QUOTE]

that's sort of right, although the pitch change is not to tell the cop whether you are braking or not, it's just what the machine does. as long as it's in transmit mode, it will track vehicle speeds, even with a locked speed on the display. the HAWK didn't have this feature, but the eagle and stalker do. on the eagle/stalker, when the tracked speed is locked, it moves to the locked speed window, and the unit continues tracking, showing the speed in the target speed window. if you didn't have a detector, and continued to speed up, the locked speed can be overriden without clearing it first. likewise, if you were coming up quick behind a car that was locked at say 120km/h, you were doing 140km/h, and the 120k car had gone past the patrol car, the cop could lock your speed on, and take you instead. the laser guns also have this feature.

[Sk8r_Boi_]

Im So Here Man Dont Know Where Tha Hell I Am...

[spudchucka]

the understanding i have of the radars in the police cars is that the tone emitted changes when locked onto a vehicle to wut the driver does. if they lock onto your speed and you brake it is meant to make a tone that gets deeper as u brake so they no u are braking. and opposite of course speed up higher pitch emitted.

Its pretty simple stuff. The radar emits a beam. It bounces back off the road to get the patrol speed and it also bounces back off the oncoming vehicles. The radar works out the speed of the oncoming vehicle by the difference between the patrol speed and the target vehicle speed. The tone is whats called the "doppler" effect and goes back to the dude (Somebody Doppler) who invented radar in the first instance.

In a patrol car the tone simply signifies, by pitch, the speed of the target vehicle.

Pitch goes up = higher target vehicle speed.
Pitch goes down = lower target vehicle speed.
Pitch is way up and suddenly goes WAY down = target vehicle is probably equiped with a radar detector (or the driver has his eyes open and can actually see that there is a police car coming towards them because lets face it they stand out like dogs balls).

[Lou Girardin]

[QUOTE=wkid_one]Not just that BB - but you can be fined under the LTSA/Traffic Act for 'interferring with vehicle surveillance equipment'.
[QUOTE]

I've been trying to find a definition of vehicle surveilance equipment, I suspect it relates only to cameras. It's intended as a deterrent to people that might want to physically express their dislike of the IRD.
The rise and fall in tone is the dopler effect, exactly the same as the sound of a fast approaching vehicle seems to increase in pitch, then drop after it passes.
BTW. Anyone else noticed the new double act on this forum. Not as interesting as Posh and Becs or as polished as Newsboy and Havoc, but practice will make perfect. What about some stage names fellas, it worked for Starsky and Hutch.
Lou

[k14]

Pitch Wavelength please people, pitch is generally refered to for the audible frequencies of sound (radar not being audible), thus change in wavelength is the scientific term.

Yes, Christian Doppler first recognised the doppler effect in the 1800's sometime. Don't think he invented the radar though. The radar sends out a radio wave at a specific wavelength, when this hits the car, it is reflected back to the radar adn since the car has velocity, the wave's wavelength is changed. From the change from the original wavelength the speed of the car can be determined.

The best example of the doppler effect is when a F1 car is coming towards you the pitch of the sound emmited from it gets higher and higher, untill it passes you, then it drops to a low pitch.

[Lou Girardin]

But isn't the sound of an F1 car audible?

[speedpro]

But isn't the sound of an F1 car audible?

and of course if they wanted to make the radars jam proof they could make them "frequency agile" as well. Or if they wanted to differentiate between two speeders close together they could "chirp" the transmitted pulse. Then they'd need a "SAWD" to compress and seperate the returns, eh?

[k14]

But isn't the sound of an F1 car audible?

Yip, thats why I called it pitch, but wavelength is just a more universal way to talk about it. It is the same for all waves, weather they be electromagnetic (light) or radio (sound) in the audible/visible or inaudible/non-visual spectrums.

Sorry, i might have made me explanation somewhat confusing.

[marty]

[QUOTE=Lou Girardin][QUOTE=wkid_one]Not just that BB - but you can be fined under the LTSA/Traffic Act for 'interferring with vehicle surveillance equipment'.

I've been trying to find a definition of vehicle surveilance equipment, I suspect it relates only to cameras. It's intended as a deterrent to people that might want to physically express their dislike of the IRD.
The rise and fall in tone is the dopler effect, exactly the same as the sound of a fast approaching vehicle seems to increase in pitch, then drop after it passes.
BTW. Anyone else noticed the new double act on this forum. Not as interesting as Posh and Becs or as polished as Newsboy and Havoc, but practice will make perfect. What about some stage names fellas, it worked for Starsky and Hutch.
Lou

if you've only just noticed it lou then at best you've been asleep

[magnum]

hello all,the last tracktime i went to some cops were there to test the handheld radar and it was surprising how hard they found it to get a good lock on especially a group of bikes together,not sure if this is the same for all there radars or just the hand held ones.i frkin hate the revenue gathering ones who patrol nice open roads especially around passing lanes.for those who arent locals 9 times out of 10 there is at least one cop[3 and a van camera once]along the karapiro straights.the van is always a red mitsi/hiace type at the end/beginning of passing lanes.

[Lou Girardin]

hello all,the last tracktime i went to some cops were there to test the handheld radar and it was surprising how hard they found it to get a good lock on especially a group of bikes together,not sure if this is the same for all there radars or just the hand held ones.i frkin hate the revenue gathering ones who patrol nice open roads especially around passing lanes.for those who arent locals 9 times out of 10 there is at least one cop[3 and a van camera once]along the karapiro straights.the van is always a red mitsi/hiace type at the end/beginning of passing lanes.

That would have been Laser.
Some models of Stalker are 'frequency hopping' within the Ka band, the best detectors still get them though. Our cops Stalkers do have a fastest target ability, that's why they are targeting overtaking lanes, easy money. It doesn't tell them which car is the fastest though, they have to rely on observation for that. But some don't bother, just ping whoever's in the outside lane. As I saw happen just north of Taupo.
Lou