does anyone know if they really work if so im willling to purchase one if not then i wont spend my money thanx
radar jammer
- Thread starter 1991GreeNLX
- Start date
I have a rocky mountain radar phazer, which is a passive jammer and is legal. They only advertise them to work from more than 50-200 feet from the cop...IE, you are speeding, radar detector goes off or you see a cop, slow down and if you slow down before 200 feet from him, you're cool, he couldn't clock you. You get into the 50-200 ft range and he may have you. Nothing is 100% fool proof, so you still have to keep an eye out as well. Mine has picked up cops from at least 1/4 mile away, probably more like 1/2-3/4 mile on the interstate sometimes--I'll be driving, it goes off and I'm doing 70-80 and it takes 10+ sec before he goes by on the opposite side. I'm glad I have mine. I believe it was $200
DCjuggalo
Member
ponycar17
Founding Member
The laws of physics dictate that it CANNOT work. Please don't make me go through the rationale as to why it can't work. I promise it will bore the hell out of you. I specialized in RF communications in an electrical engineering degree...
sic91sleeper
Founding Member
I honestly am bored here at work and would be interested in hearing why the laws of physics prevents the radar jammers from working.
were you talking about me?DCjuggalo said:
5spdGT: Valentine 1 is a detector, not a Jammer. From what I hear, Valentine 1 is the best detector out there and the arrows are probably really nice--I want one, but they're expensive.
ponycar: I, too, would be interested in hearing why it can't work. The passive jammer, as i'm sure you know, emits an FM frequency-which is perfectly legal-which interferes w/ the police radar. Active jammers capture the police radar and don't send it back, which is illegal. FM interference happens all the time, so I don't see how it's impossible for a jammer to do this. Please enlighten us.
funny I came across this cuz I just got a speeding ticket tonight, 65 in a 50kmph zone. Those of you who are familiar with ontario laws, I've heard that it's possible to pay within 24 hours and nothing goes on the insurance records. Is this true.
After tonight I will surely be buying one of these radar detectors or jammers, speeding tickets suck.
So why cant they work?
After tonight I will surely be buying one of these radar detectors or jammers, speeding tickets suck.
So why cant they work?
so should i spend my money on one or not? all the people in th gumball race seem to use them ? not that gonna be in on but i mean i know radar detectors work so why wouldnt a radar jammer????????????? 
This gonna be totally your call man. I suggest you read and research all of your options. I personally have the phazer. I probably will buy a valentine 1 one day, but I have 3 vehicles, so I'll still use the phazer. I've had it for about a year and a half and I like it. Really...you have to pay attention and watch out and not be a moron or you can get caught w/ any detector/jammer. If you pay attention AND have a jammer, you're cool, but some jammers (active jammers) are illegal and phazers are illegal in California I believe.1991GreeNLX said:so should i spend my money on one or not? all the people in th gumball race seem to use them ? not that gonna be in on but i mean i know radar detectors work so why wouldnt a radar jammer?????????????
The phazer also comes w/ a guarntee that if you get a ticket within the first year for under 15 mph over the limit, they'll pay it. I got one ticket when I first had it and it was because I was doing 110 in a 70, saw the cop and someone told me about him ahead of time, but I waited to hit the brakes -- managed to slow down to 86, which was 16 over; he wouldn't write it for 85 either -- I asked
ponycar17
Founding Member
TheUser said:
First, active jammers do send a signal back. You can't physically capture a signal, and not send it back. There are certain coatings that absorb EM waves better than others, but no electronic device can make a wave dissappear. You can somewhat cancel a wave out by transmitting something that's 180 degrees out of phase with that wave, but even then, there's NOT perfect cancellation if you don't have a predictable signal. And even then, the first signal cannot be cancelled because of device processing time to determine what it needs to transmit back. You'll notice that the F-117's materials and shape have MUCH more to do with being invisible to radar than any electronics. That plane deflects radar so that the ground receiver can't receive the signal back as effectively, plus its coating which helps absorb RF waves. An active jammer would emulate the signal it detects, manipulate that signal and send a similar one back. I'm not sure how in the world they're expected to work. EM waves travel at 300,000,000 meters per second approximately (the speed of light). If a cop caught you in line-of-sight at 100 yards, or approximately 91.44 meters, that's a travel time of the RF wave of 0.3 microseconds (that's 0.0000003048 seconds). Keep in mind that there's NOTHING that will slow the wave down under normal conditions. An active jammer would have to mimic the wave after first experiencing the wave to measure what it is exactly. So, let's say the jammer is capable of mimicking the wave in 1 microsecond. In that 1 microsecond, the wave has already been reflected back to the cruiser's radar, and send another wave which has already come back again. That's two waves before your "jammer" have even responded, and sent anything.
Now, you need to know a little about transmitting radio waves. A radar that police use, uses a "horn" antenna that is optimized for the particular band it's operating in. Horn antennas are commonly used in microwave communications because of their directivity, high gain, and compact form. Your "jammer" would have to be capable of many bands, therefore a multi-band horn antenna. That very property makes the antenna less efficient. Antennas' receiving ability is measure by a property called "gain " in decibels. 3dB is twice as much power as 0dB, and also twice the ability to receive a signal. Since your radar "jammer" is made with an antenna of very low "gain" so it can operate in many bands, you have less transmitted power. The cop's gun is optimized for its particular frequency, and he's also allowed to transmit more power than you are as well... You're allowed to transmit 500 mW; that ain't jack in the microwave band...
So, here's the summary:
You're hindered by the fact that your "jammer" can't react quickly enough to transmit a signal to interfere with the cop.
You're hindered by the fact that your antenna isn't optimized for the frequency he's trying to detect.
You're transmitting less "effective radiated power(ERP), which is because you're starting with a smaller signal and your antenna gain is effectively crap.
Now, if you're just transmitting "white noise" which is what it sounds like this thing is doing, here's your problems. This would be the case for your passive design...
A horn antenna is VERY directional. Typically, the gain is highest near the very front center of the antenna, and tapers off at about 15 degrees from center. The signal on the fringes of the radiation patter is said to be "rejected"... Unless you're perfectly aligned with the cop's radar, you're not going to overpower his signal... Why, you ask? It takes 3dB more power to overpower another signal typically. You're likely not facing the cop's radar directly; because, after all, he's AIMING for you, and you're already transmitting less power, as I've already explained. His antenna functions the same as yours. It's very directional, and he receives from a very small path in front of his gun/antenna.
There is a very small possibility that if you detected a radar signal around a curve that was reflected off of something, you'd be able to emulate that signal before he's right on you... But then again, in that case, you're still playing the cards. It's HIGHLY unlikely you'll overpower his signal and have any effect on his receiver. And in the event that you're spotlighted (turning the gun on for just a second, while previously having it off), you're definitely screwed... There's no way at all to prevent that from being detected with your "jammer."
You can read the manufacturers' hype all you like, but remember, they're selling a product. I have nothing to gain my sharing this information. And the biggest question you have to ask yourself is this; if it really worked, would they allow them to be sold?...
Now that you're thorougly bored from reading my nerdy explanation, I warned you not to ask me to explain...
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