Radars detectors legal?

[huck farley]

I'm not really sure thats entirely true.

The ideas in my previous post on how to build a jammer are technically quite accurate !

In the USA, an active jammer would be illegal due to licensing, and the FCC would hammer any company that made or sold such a device.

Not so here, its a public use radio band in NZ.

EDIT - particularly PLAN B ! as its a passive system.. as used by the UK in WW2

At the time I was talking to a technician in the states is because I had bought one of the Bel range RD that had a magic shield that fitted onto the device. Also the device ran on two AA batteries so I was able to slip it in my pocket. and it was kept high and dry.

It worked ok It saved me a couple of times But on one occasion it failed me doing 123 along the Desert Road. I received a $180 fine and 30 demerits. It took me a while to suss out why it failed me. I read the instruction book again and I missed the bit where it said that if no activity after one hour the device shuts down to conserve the battery life. Hence me getting lumbered.

However I rang the USA to see if there was anyway I could override this turning of business. (I bought it on the Internet from the USA) was told that if I touched one of the buttons on the device it would switch back on Immediately.

I commented that's hard to do when traveling at speed with gloves on. He agreed!! it was a oversight and would pass on my comments. NOW In general conversation I asked him about Ka band Jammers, he said the same thing as you. That being they are illegal in the USA but went on to tell me they were useless anyway, and to give them a wide berth. I just thought I would clarify that for you Dave. (I have since gotten rid of my Bel RD on trademe) I have a Scorpoin RD for sale Only used it in my Audi. Give me a PM if anyone wants to buy one. it is in excellent condition....

[mowgli]

I feel sorry for all you worry-warts who view a radar detector/jammer as a life support sytem, FFS get a life and learn to ride without getting tickets.

Bling! Only one stupid mobile camera fine in 20 yrs and that was when they joined up the northern motorway extension and reduced the limit approaching Silverdale. 81 in a 70 zone - fun taxes paid up for another 20 yrs I reckon.

[mowgli]

I'm not really sure thats entirely true.

The ideas in my previous post on how to build a jammer are technically quite accurate !

In the USA, an active jammer would be illegal due to licensing, and the FCC would hammer any company that made or sold such a device.

Not so here, its a public use radio band in NZ.

EDIT - particularly PLAN B ! as its a passive system.. as used by the UK in WW2

Option A: To build microwave circuits you can't simply head down to Dickies for a soldering iron and a few resistors.

Option B: DIY cutting and positioning errors _MAY_ enhance broadband performance but are more likely to reduce the overall effectiveness of the antenna array.

Option B: Rotating will produce both Doppler up and Doppler down with the centre frequency giving away your actual speed.

Even if you do seduce the police radar then you've neglected to consider burn-through range - the distance from the radar where your bike reflection is stronger than the transmit power of your deception device.

Nice ideas but don't waste you time.

[scumdog]

The plan..

35Ghz has a wave length of 8mm. So a short bit of wire, 8mm long is resonant, and will be a much better reflector than your car.

Get a 200mm longish, round bit of wood, like an old shovel handle.

At 8 mm spacings from one end to the other, glue on 25, 8mm long "reflectors". This is a really good target for the radar unit.

The do it again, a bit further around the circumfrence of your handle.

Keep doing it until you have dozens of little reflectors on your handle.

Now, place the handle behind a 200mm long bit of angle iron or aluminium. Arrange things so that the very top reflectors are just higher than the top of the aluminium, as viewed from the police car.

Now spin the handle with a small motor.

How does it work ?

From the police radar point of view, all it can see is the row of reflectors at the top of your device. But they are moving, as you are spinning them with a motor. And they are moving at a speed you control.!

You should be able to preset any speed you want to be shown on the police radar unit.

"Stalkers" would be very vulnerable to this technique, as they try and process both highest speed and strongest target.

This would create the crazy result where the police claim "one vehicle in beam" but the radar unit shows two, entirely different speeds.

Off to the workshop lads !

You DID watch Mythbusters when they tried this sort of device didn't you?

And you DID see it didn't work?

And you did see the size of the one they built?

The size of a washing machine mounted on their 'stealth' undetectable car.

[davereid]

lol.. well, a few tech ideas certainly fired up a hornets nest !

The post was intended as a bit of a laugh... but it has certainly demonstrated how concerned people are about radar !

So while admitting that it was a bit of a joke, and shouldn't be treated to seriously, ... its also technically not quite as weak as it may seem.

Scumdog :
No sorry I didn't see Myth-busters.

I don't know what they tried to build, so I can't comment on its effectiveness.

My device would NOT produce a "stealth" vehicle - quite the reverse, I am adding reflectors, in fact my vehicle would provide a better target, just the stalker would incorrectly report the antenna array speed instead of the vehicle.


mowgli :
The antenna as described was a stacked array - as you commented the dimensions would be critical. They would be possibly un-buildable by hand but quite obtainable by machining. ie lay the antenna in strips, then mill or turn out sections as required.

The issue of rotating antennas producing doppler "up and down" is solved by the metal shield.

Unless I have missed something obvious, the design will provide only one return signal, which is the (rotational) velocity of the antenna, plus the actual velocity of the vehicle.

Burn through range is not a problem with the Stalker. I am deliberately exploiting a feature of the stalkers design, in that it has a homodyne receiver, and will receive and process ALL incoming signals, not just the strongest.

It cheerfully tracks both strong AND weak signals. It will display the strongest signal and the fastest signal.

Huck:
It will only work on doppler shift radars, and as it exploits the particular design of the Stalker DSR, it may not work against other doppler radar units.
It would never be effective against LASER, or pulsed radar.

Get building !

[davereid]

Option A: To build microwave circuits you can't simply head down to Dickies for a soldering iron and a few resistors.

Oops forgot.. quite right, you cant get the parts from DSE. But radio hams have been using microwave for 50 years. Go see the lads at your local radio ham club. They will likely have a 10-11 GHz Gunn Transmitter lying around, and that becomes 34-36 GHz with a simple trippler. (Nick the diode you need fom the antenna head of your neighbours Sky Dish).

[Ixion]

CAn a police radar measure the speed of a target moving AWAY from the radar . EG, cops have rear facing radar, if the cop has passed you in the other lane, will his radar get a valid reading on you as you move away from him. Presumably the Doppler shift would be negative ?

[slopster]

CAn a police radar measure the speed of a target moving AWAY from the radar . EG, cops have rear facing radar, if the cop has passed you in the other lane, will his radar get a valid reading on you as you move away from him. Presumably the Doppler shift would be negative ?

As I understand only if they have a radar mounted in the rear window which only a minority of them do. This was explained to me by a cop who didn't do traffic duty's though and also was a few years ago so may have changed.

[NUTBAR]

No, it hasn't upset me at all, I just think that its pathetic and melodramatic bullshit.

Public opinion of police is a two edged sword, you can't do the work required of police without upsetting one sector of society or another for various reasons. And, if the police went about their work with the primary objective of keeping the public happy at all costs then you would have a corrupt force in no time.

You're making a big fuss over the 10kph tolerance and accusing me of being brainwashed and indoctrinated because I say its a fair tolerance. And now you think you can comment on the work I do personally and criticise me if I think I've done a good days work. Get a grip of reality, you don't even know what I do on a daily basis.

I'm glad that its a job you wouldn't choose, its a better organisation because of that, thank you. You are right though, somebody does have to do it, you should be grateful that there are good people around that have the guts to step up and have the strength and fortitude required to withstand the daily moaning of ignoramuses.

well said.

[fredie]

its like about 10 points and $1,500 aus$ fine here . u only have 12 points on your licence here in nsw aus

[scumdog]

Scumdog :
No sorry I didn't see Myth-busters.

I don't know what they tried to build, so I can't comment on its effectiveness.

My device would NOT produce a "stealth" vehicle - quite the reverse, I am adding reflectors, in fact my vehicle would provide a better target, just the stalker would incorrectly report the antenna array speed instead of the vehicle.

:

Ya got the wrong end of the stick.

The Mythbusters 'device' was designed like yor idea - to reflect back a signal to show a slower, incorrect speed.

It did not work - the rader was not affected.

[Delphinus]

Wouldn't you want it to read a faster speed, like 300 or 400 or something you know is impossible?

[Swoop]

My device would NOT produce a "stealth" vehicle - quite the reverse, I am adding reflectors, in fact my vehicle would provide a better target, just the stalker would incorrectly report the antenna array speed instead of the vehicle.


The issue of rotating antennas producing doppler "up and down" is solved by the metal shield.

The rotating piece of wooden rod would make a handy rotisserie device for when you are away camping!
It would cook the roadkill quite nicely.

[swbarnett]

CAn a police radar measure the speed of a target moving AWAY from the radar . EG, cops have rear facing radar, if the cop has passed you in the other lane, will his radar get a valid reading on you as you move away from him. Presumably the Doppler shift would be negative ?

Doppler Radar works by measuring the change in frequency of a reflected sonic beam. The direction the object is travelling is irrelevant, it just changes the calculation slightly.

[spudchucka]

CAn a police radar measure the speed of a target moving AWAY from the radar . EG, cops have rear facing radar, if the cop has passed you in the other lane, will his radar get a valid reading on you as you move away from him. Presumably the Doppler shift would be negative ?

Yes, its just a matter of telling the device whether the target is approaching or going away from you, (a press of a button on a remote control).