Radar through a dark tinted screen

[Morcs]

Just wondering if it will work...

Radar will work through plastic upto 1/4 inch thick, but the screen is like an infared lens... wonder if it will screw up signals.

I havent tested yet as I blew my new detector up (wired up wrong heheh) but the laser was going balastic anyway (though not meant to have anything in front of laser)

Will test when new unit arrives, but need to know if it should work otherwise will have to find an alternative mounting place. And more cutting of fairings...

[robertydog]

Ive got a dark tint screen and use a Bell STI and i find it works fine.

[johan]

I can have my Bel RX65 detector on the floor next to me in my van without a rear window, and it picks up a signal 3-500 meters behind me.

Obviously you need line of sight for the laser detector to work. I'm not sure you're asking for laser detection or the radio bands?

[Pumba]

I havent tested yet as I blew my new detector up (wired up wrong heheh)

And that is why I hate playing with electrics.

Mine was fine through the dark tinted screen I had on the SV

[Morcs]

Yeah so far its been an expensive exercise - buying 2 complete radar units within 10 days!

But I got some good scores, 1st one was $300, 2nd one was $270 - compare that to the NZ price they used to go for - $650 each and im still winning

[HungusMaximist]

Hey bro, where did you get your radars?

I am sort of on the same track as you and looking in getting something down the track (I think in july when the gov decides whether or not to ban it), I've got a tinted iridium screen, though I do have my original screen.

[Finn]

Yes, radar will work through your screen. Take a look at the business end of your radar. Its got a plastic cover and it still works.

[Waxxa]

I'm actually looking at getting a laser jammer. A detector will let you know a cop is around, but a jammer will hinder the cops ability to detect your speed!

[Finn]

I'm actually looking at getting a radar jammer. A detector will let you know a cop is around, but a jammer will hinder the cops ability to detect your speed!

Slight correction there chap... You can buy a laser jammer, not radar jammer.

[Waxxa]

Thanks Finn.

[lordandrevv]

pretty sure jammers are illegal, as they interfere with the police doing their "job". And from what I've heard there aren't really any laser jammers that work to well...radar probably.

[Waxxa]

A friend of mine has recently fitted a jammer into his car (front and rear) so they are available out on the market. They are a small unit so you can fit them in an inconspicous place on a bike so its not visible.

Need to ask him if its for radar or laser.

[Pumba]

A friend of mine has recently fitted a jammer into his car (front and rear) so they are available out on the market.

Bit of weird law, they are not illegal to buy or even have fitted to your vehical(correct me if im wrong on that one) but they only become illegal the moment you turn them on.

[CookMySock]

A radar jammer is a transmitting device - likely it will have to be type-approved byt the ministry of commerce, and c-ticked and every other damn thing under the sun, as it shares the radio spectrum with other users.

A laser jammer is a low-power laser device, like a kids-toy laser-pointer. There are little or no regulations on these, and you can point it where you choose without care.

It is possible that if you use a laser device to deliberately obstruct an officer, then they (rightly) might take issue with that. You can use any seemingly innocuous item you choose to obstruct an officer (donut?) and it's still obstruction.

A detector doesn't obstruct anyone or anything.


DB

[davereid]

A radar jammer is a transmitting device - likely it will have to be type-approved byt the ministry of commerce, and c-ticked and every other damn thing under the sun, as it shares the radio spectrum with other users.
A laser jammer is a low-power laser device, like a kids-toy laser-pointer. There are little or no regulations on these, and you can point it where you choose without care.
It is possible that if you use a laser device to deliberately obstruct an officer, then they (rightly) might take issue with that. You can use any seemingly innocuous item you choose to obstruct an officer (donut?) and it's still obstruction.
A detector doesn't obstruct anyone or anything.
DB

Yep !

In NZ, police radar operates in a Public band, with a general licence for radio location. (ie radar and its derivatives.) So, anyone can use it. Of course the device should meet certain standards, particularly with relation to the power it radiates.

If you were to build (or use) a device that had the purpose of defeating police radar, you would be breaking the law.

Of course, as you share the band with police, if you were to build and use a device that had a real use, and it just coincidentaly jammed police radar, then that would be fine, as the band is shared.

Would it be easy to build a jammer ?

Yep, very very very easy. In fact, its RF electronics 101.

You need a handfull of parts...

The Gunn diode - cavity - and wave guide from the cheapest radar detector you can buy is a good starting point.

You have to know how your radar detector works to understand...
In your radar detector, you actually have a radar transmitter, pretty close to the police radar frequency. The waveguide on your radar detector tunnels the police radar transmission towards the cavity containing your own transmitter, or an adjacent cavity. The two signals mix (heterodyne). The result is all the sum and difference frequencies between your transmitter, and the police transmitter. The radar detector knows the police frequency. And it knows yours. So it knows what difference to look for, and it sounds an alert if it sees this difference frequency. Of course, your frequency, and the observed police radar frequency vary. With temperature, aging of components, and doppler effect. So, both your radar and the police radar, are very broadband - they look for signals in the "right area", not just "right on".

So, how would one jam police radar if one was to do it ?

Simply drill a bigger hole from the cavity containing the oscillator (gunn diode) to the waveguide/antenna looking for incoming signal. Now you are pumping back lots of signal at the police radar.

On its own, if you are lucky, this will jam the police radar, as it will recognise the interfering signal and refuse to give an opinion on your speed.

You can do better. By "AM" modulating the signal that you send back, you can decide what you want you speed to be. This is because the police radar uses dollper shift to detect your speed. So it mixes the signal it transmits towards you with the reflected one. It expects about 19hz change for every km/hr you are doing. So if you am modulate the sgnal you send back at 1900 hz... you are doing 100km/hr regardless of your real speed.

Have fun !