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Radar jammer


— Posted by The Doctor on 6:43 pm on Mar. 17, 2002

Hey does anybody knwo how to make a effective radar jammer (and laser jammer)?


— Posted by Just0nePepsi on 8:39 pm on Mar. 17, 2002

trust me its easier to buy one


— Posted by The Doctor on 10:15 pm on Mar. 17, 2002

OKay thanks I’ll just get AT&T to pay for it :)>


— Posted by XxBULAxX on 11:19 pm on Mar. 17, 2002

instead of making a new topic, why not add to this topic:
http://www.bombshock.com/cgi-bin/ib/topic.cgi?forum=5&topic=84


— Posted by Jack17B on 5:18 pm on Mar. 21, 2002

hi, I’m new to this forum.
I thought I might as well add some comments to help people out.
You cant actually ‘jam’ radar. A radar is a burst of radio waves, broadband,  that reflect off objects and are detected. The delay and orientation of the waves gives an exact location. However, certain materials absorb a significant amount of radio waves so the echo will be small, possibly undetectable. Such a material is Iron oxide (Fe2O3), Rust to be exact.  Ironicly, the oldest boat/plane will be the hardest to find.
There is no such thing as a ‘laser jammer’, a laser does not work in a way that can be jammed. Maybe a thick mirror would be a good idea.  I could tell you how to make a radio jammer to disrupt television, CB radio etc.
I hope this will be of use to you.


— Posted by johnny 99 on 1:16 am on Mar. 22, 2002

Jack, whats your Idea for a radio jammer?


— Posted by Zambosan on 11:02 am on Mar. 22, 2002

Police radar can be jammed just like any other RF device by generating a lot of in-band noise.  If you decrease the signal-to-noise ratio below the threshold that the device can tolerate, it won’t be able to correlate the received information to the pulses of RD energy it sent out, and therefore can’t calculate a delay for it.

For those of you who care to know, radar typically emits a “chirp” signal; this is a signal whose freqency ramps from a low initial to a higher final frequency.  The reason for this is that, unlike an impulse, it can be transmitted with a finite amount of power, and since it is a band-limited signal (occupying a defined bandwidth), it can be efficiently transmitted.  When the reflected signal returns, it is a delayed version of the original.  After sending, the signal processing hardware (or DSP software) starts a timer, then begins convolving the received signal with the time-reversed chirp signal; this is a “matched filter”, or auto-correlator.  The beauty of using the chirp instead of a constant frequency is that the correlator output will be very low until the received sequence *exactly* lines up with the copy of the sent signal in the correlator, at which point the correlator output will jump high… an impulse!  Since the width of an impulse is very narrow, there is a lot less error involved in calculating the exact amount of time to travel.  This can be plugged into a simple linear equation to tell you how far away the target is.

Police radar is actually Doppler radar; if the target is moving, there will be a positive or negative frequency shift (depending on whether the car is moving toward or away).  Before correlating the current and previous values of the Rx signal, the DSP will first translate its frequency by interpolating it.  It does this translation for all acceptable speeds (the range of speed that the gun can detect), and then selects the shift value for which the correlator output is highest.  If the value is above a certain threshold, it decides it is the reflected pulse.  The amount of shift, coupled with the known speed of RF waves through air, reveal the speed of the object it reflected off of.

Stealth technology makes use of absorbtive materials and very narrow edges to minimize the amount of reflection (just look at the B-2).  To see this effect on visible light, stack up a bunch of razor blades and look at the sharp ends; it will be nearly black because of the way the edges reflect the incident light away from your eyes.


— Posted by Morgan Thomas on 10:59 am on Mar. 24, 2002

I sent you a email on this topic, after much research on this topic it seems like the RFI approach is the most viable. Please take a look at my postings on this subject and help me get started on the right path toward making the RFI light glow on the radar gun control panel.
Thanks so much in advance for your help.
Morgan Thomas


— Posted by Zambosan on 11:39 am on Mar. 25, 2002

Essentially, you’d need to add an amplifier stage and an efficient antenna rated for the power.  The RFI kill feature is designed to shut down the radar when the officer is using his police radio to prevent interference.  However, you would need to pump out an awful lot (probably an unhealthy amount) of RF energy for this to be effective even at moderately short ranges.


— Posted by Morgan Thomas on 10:17 pm on Mar. 25, 2002

Maybe I asked the wrong question, How would one go about constructing the device you spoke of in your origional post on this topic? Please read the post /replies I’ve made on this subject and make whatever beneficial suggestions you might have on this topic.  I am about to decide that amidst all the bombing,
and high tech BS flying around on this site, not one person has the knowledge / expertise to make a simple electronic device to jam a radar unit owned / operated by a simpleton “local Yokel” ego with a badge!  People make suggestions , then state why what they suggested won’t work. Could anybody take a short break from the “star wars”, “star trek” BS ( that they probably have no possible way of making work) and come down to earth for a brief visit and think about the construction of a viable device with a practicle purpose?
I have a very limited electronics expertise, but several other topics on this site I have some info worth sharing.
If anybody on this site has enough electronics expertise to make modify one of these devises, I would pay for that information, I really want to construct something viable. Does anybody have a clue?


— Posted by Zambosan on 10:34 am on Mar. 26, 2002

Yes, I have a clue, I have a degree in computer engineering and work on digital hardware and software for a living.  My original post described the theory behind jamming radar; generate a lot of RF noise.  If you expected me to spend weeks of my time designing RF and control circuitry, selecting components, building, testing, and documenting a system so I could hand it to you on a silver platter, you’re out of luck.  Like most worthwhile things, this would entail a decent amount of work and more than just a passing knowledge of electronics.  Sorry if you expected me to say “Just open up your radar detector and clip the green wire, Voila!”, that’s not how it works.  It’s not as complicated as a cell phone, but it’s still not a “simple electronic device”.  You have admitted that you have absolutely NO clue about electronics, yet you’re bitching because you don’t think anyone else does.  If you really need to speed all that badly, you’ll spend the time and money on an engineering education and then work it out yourself.  If that sounds like too much effort, imagine it from where I’m standing.  There is not a “cookbook” for everything, get that idea out of your head.


— Posted by Morgan Thomas on 7:03 pm on Mar. 26, 2002

I do understand, I have a BS in Biology, Masters Degree in Chemistry, and Two Engineering degrees; one in The Mechanical discipline, and one in the Nuclear displine. If I came across as a uneducated, mouth breather with a lead foot & no idea of how to design a viable radar countermeasure, I think I projected the wrong personna.  I just get confused / frusterated at all the different  “bits and pieces” of info that people post
and try to get some angle on the truth. I have converted radar detectors ( for X & K bands), tried to mate a Gunn Diode oscillator to a tunable wave guide, etc. I have put forth a lot of time / effort / research to developing a viable device and probably gained more useful info from your last posting than from several other avenues I’ve pursued. I believe you probably have the expertise to at least know what the solution  would involve.
 Of the info I’ve come across there seems to be three viable options:
1. Actual active jamming of the radar waves on the generated wavelength.
2. A guy that sold radar guns to the cops told me that a modified CB radio could be produced that would generate enough radio intereference to cause the RFI light to come on & make the radar unit unable to get a “lock”, I guess this would be called the “radio noise” option.
3. “pinging” is a totally different approach. It involves modifying a ham radio to local /state/ city police frequencies (and repeater frequencies). When the mike is “keyed” the resulting squelch trail magnitude would be quantitatively measured to indicate the relative distance between you (your car) and the police radio (with the radar gun on board).

I’ve even developed a single line schematic ” control / feedback loop”  of a system that incorporates all three concepts into a single system.

I personally use a bel 980 detector & a Uniden BCT scanner ” bear tracker”, and I’ve been fairly successful with them. Ka band radar, and “instant on” radar, represent two big “chinks” in my armor.

I don’t expect you to do any type of elaborate R & D on this subject for me, but could you shed some light on which of the three options listed above are the most viable / practical to pursue? Maybe none are, maybe something else is, maybe all the info I’ve been given is bunk, but a honest answer /good intelligent feedback is worth more than half baked theories ( that I usually get off the web).
If I know some good reason / firm basis to travel down a particular path, I can find out how to construct the device. I know a lot of Engineers, and they know a lot more engineers, but my current problem is that I don’t know for sure what to ask them to help me make / develop.

Another possible option might be a aimable EMP gun. The beauty of this device is that the cruiser ECM chip will get fried, the radar gun will go up in flames, and the radio will fade to black. If you can’t be clocked, chased, or “cut off at the pass” by  a radio, it has all the trappings of a wonderful day. I hear a lot about this type of device, don’t really know it’s application limitations, feasibility, etc. Does this type of device really exist in a portable, effective, sufficiently powerful form?

Thanks in advance for the reply / info /help/ advice,
Thanks again,& email me directly if you like at mmrmcthomas@aol.com
   


— Posted by Zambosan on 9:26 am on Mar. 27, 2002

Okay, sorry if I overreacted… I didn’t have you pegged as a “mouth-breather” (LOL, Cletus the Slack-jawed Yokel from the Simpsons :biggrin: ).  The pinging approach seems awfully interesting… never heard of that before, but I imagine that the accuracy would be pretty difficult to characterize due to all the variability in signal strength, propagation due to different topology, etc.  I would say that the most widely applicable approach (and also least difficult to construct) would be to modify a CB to cause the gun to disable.  I don’t have an FCC chart in my head, but you can probably very easily look up the bands reserved for police and emergency use.  Most CB’s still operate by using a crystal oscillator to generate the FM carrier frequency.  This can be swapped out pretty simply with a crystal that will generate carriers in the police range, giving you an instant police radio (with the ability to transmit as well).  Get the schematic for the CB if you can (or conversely, get a CB that you have a schematic for!)  There are several types of crystals, but CB’s usually use AT-cut (not AT-strip) crystals since they are cheap, although they have poorer temperature drift characteristics.  There are lots of CB modification pages & clubs out there.  Get a cheap one with few bells & whistles and you’re likely to have a PC board that’s easier to work with.  To get an effective range, you’ll want to boost the power; CB radios are limited by the FCC to I believe 5 watts.  HAM radio suppliers can probably get you an RF amplifier that will provide a second stage of gain at the antenna output.  Then you will need an antenna… I’m not really sure what the best choice would be.  Since the nature of the application is omnidirectional (you’re worried about cops in front, behind, to the side) you would probably want a common “whip” antenna, but that’s kind of conspicuous.  A circular array of directional antennae would be better and could have a lower profile, but would be harder to come by.  As far as the input signal, you can create a simple noise generator from a 555 timer circuit; you can look up a simple oscillating circuit just about anywhere on the net, takes a $1.50 555 IC and a few resistors and caps.  Generate a square wave in the voice frequency range, 1 kHz should be easy with standard resistor & cap values.  Filter the output through a series capacitor to block the DC component of the square wave output, then run through a simple op-amp inverting amplifier; a 741 is a cheap, good choice.  Again, a circuit for this can be found anywhere, and even Radio Hack sells little books with simple 555 and 741 circuits.  You will probably need to attenuate the signal a bit, as this essentially sinusoidal signal will be driving the wires that used to be connected to the microphone in the handset.  The keying switch on the handset can be replaced with a toggle switch to turn the transmitter on & off, but all that will be transmitted is just a 1 kHz tone; if you use a potentiometer for the feedback resistance (or a portion of it) on the op-amp circuit, you can adjust it to get maximum volume without clipping.
And that’s about it… this is just a device that will transmit in the police band at high-ish power to hopefully switch off radar as you get near.  Make sure you’re not pumping too much power for safety’s sake… in college some cohorts and I literally cooked some corn dogs on the roof of the college radio station when we were installing a new antenna & PA… but that was at ~1000 watts & pretty close to the pole.  Also, bear in mind that you may be interfering with emergency personnel as well… and they may be trying to save someone’s life.  If you transmit with this thing in one area for too long, the fuzz *will* get someone to triangulate your position and bust you… and even transmitting at normal power on an emergency/police channel without authorization can carry serious consequences.


— Posted by xenonalieninfo on 8:34 pm on Mar. 27, 2002

a radar jammer just get a piece of tinfoil
for a laser jammer get a mirror and deflect it away from target


— Posted by johnny 99 on 8:40 pm on Mar. 27, 2002

How do we deflect you from makeing ignorant posts like this????


— Posted by xenonalieninfo on 8:49 pm on Mar. 27, 2002

johnny 99 you are ignorant, the stuff lested above, is write.

tinfoil makes a big fucking dot on there radar screen , so small aircraft can fly throught, and have less chance of being dected(presice loctation).(shore it ant going to work if they seen a plane after you ,but for AGS(auto gudinace system) what they use on AA guns, it decreses the change of them hiting you by 20%, just by haveing a coke can size piece of squashed tinfoil.

and don’t get me started on a mirror


— Posted by Morgan Thomas on 8:53 pm on Mar. 27, 2002

You are a sharp cookie indeed, I have several of the cb mod sites already book marked.  I also have a file saved w/ all the frequency ranges for the various Radar bands saved too. I believe Ka band goes from about 32. something to about 35. something, (I’ll have to look up the exact ones). I will take the lead & melt some solder , Thanks more than you know. I’ll keep you posted on the progress, & may need some more info If I get stumped in the future. I think I now have the keys to the Kingdom.
Thanks again


— Posted by xenonalieninfo on 9:05 pm on Mar. 27, 2002

are you meaning kilo hetrz,
if your are they go from 1 to 10000(computer network terms)


— Posted by johnny 99 on 10:39 pm on Mar. 27, 2002



Quote: from xenonalieninfo on 1:49 am on Mar. 28, 2002
johnny 99 you are ignorant, the stuff lested above, is write.

tinfoil makes a big fucking dot on there radar screen , so small aircraft can fly throught, and have less chance of being dected(presice loctation).(shore it ant going to work if they seen a plane after you ,but for AGS(auto gudinace system) what they use on AA guns, it decreses the change of them hiting you by 20%, just by haveing a coke can size piece of squashed tinfoil.

and don’t get me started on a mirror


 First of all , The word that you are trying to use is ( right ) . The second thing is that the name of the post is radar jammers! If you will go reread your own post, or better yet some of the others I think that you will find that tin foil DOES NOT jam radar! Infact just the opposite. If you had bothered to read the thread you would know that it’s police radar, not a fucking AA gun thats being talked about. And that mirrors were already mentioned, and it wasn’t a very good Idea the first time. Now stop posting senseless drivel!  


— Posted by Zambosan on 11:03 am on Mar. 28, 2002

Don’t worry Johnny99, X.A.I. will not be with us for much longer.  Good luck Morgan… I forgot to comment on the transmission of radar signals as opposed to communications frequencies; I believe the equipment would be much more difficult to get ahold of and much more expensive.  Also, the frequencies are higher, making it much more directional (that’s why they work in a radar gun, right? 🙂 ), so you might need several, and the power requirements would be pretty taxing on your automotive electrical system.  I think a high power comm. signal as described is your best bet.  Still, it’s iffy, and you don’t exactly have a fertile ground for testing (how many cops are going to let you test on them voluntarily? 🙂 ).  The close proximity of the cop’s own radio to the gun is a big factor; the sensitivity to the RF can be pretty low since the two antennae are so close together, and EM fields fall off as the inverse square of the distance… so you may need to pump some serious power.  If the guns are designed to turn off even when *other* cops in the area transmit, then you may be in business with a lower powered transmitter; I’m just not sure if they are.


— Posted by xenonalieninfo on 7:12 pm on April 2, 2002

chaffs/flares – ECm jammer pod same diff


— Posted by xenonalieninfo on 7:16 pm on April 2, 2002

zambosan
think about what you said

you kick me off i just choose a different login
try just telling other people i’am a ingotrent little faqqit

and i would love to met you in person or over the phone
you sheem like the guy i met in wellignton(if not say so)


— Posted by Zambosan on 11:04 am on April 3, 2002

I can’t decipher half the words you write.  You irritate the crap out of me, NO you’ve never met me, I live half a planet away.  I’d rather not waste my time flaming you, you refuse to stop grinding the little gears in your head to see what nonsense you can fabricate to post next, rather than stop for a moment and see if there’s anything you can learn.  And if you’re banned, you’re banned by IP, not by name.  If you have a dynamic IP, it can still be done by masking.  So I’d suggest you put an end to your verbal diarrhea and post only when you have something truthful to say.


— Posted by Hitman on 5:34 pm on April 4, 2002



Quote: from Morgan Thomas on 7:03 pm on Mar. 26, 2002
I do understand, I have a BS in Biology, Masters Degree in Chemistry, and Two Engineering degrees; one in The Mechanical discipline, and one in the Nuclear displine. If I came across as a uneducated, mouth breather with a lead foot & no idea of how to design a viable radar countermeasure, I think I projected the wrong personna. I just get confused / frusterated at all the different “bits and pieces” of info that people post
and try to get some angle on the truth. I have converted radar detectors ( for X & K bands), tried to mate a Gunn Diode oscillator to a tunable wave guide, etc. I have put forth a lot of time / effort / research to developing a viable device and probably gained more useful info from your last posting than from several other avenues I’ve pursued. I believe you probably have the expertise to at least know what the solution would involve.
Of the info I’ve come across there seems to be three viable options:
1. Actual active jamming of the radar waves on the generated wavelength.
2. A guy that sold radar guns to the cops told me that a modified CB radio could be produced that would generate enough radio intereference to cause the RFI light to come on & make the radar unit unable to get a “lock”, I guess this would be called the “radio noise” option.
3. “pinging” is a totally different approach. It involves modifying a ham radio to local /state/ city police frequencies (and repeater frequencies). When the mike is “keyed” the resulting squelch trail magnitude would be quantitatively measured to indicate the relative distance between you (your car) and the police radio (with the radar gun on board).

I’ve even developed a single line schematic ” control / feedback loop” of a system that incorporates all three concepts into a single system.

I personally use a bel 980 detector & a Uniden BCT scanner ” bear tracker”, and I’ve been fairly successful with them. Ka band radar, and “instant on” radar, represent two big “chinks” in my armor.

I don’t expect you to do any type of elaborate R & D on this subject for me, but could you shed some light on which of the three options listed above are the most viable / practical to pursue? Maybe none are, maybe something else is, maybe all the info I’ve been given is bunk, but a honest answer /good intelligent feedback is worth more than half baked theories ( that I usually get off the web).
If I know some good reason / firm basis to travel down a particular path, I can find out how to construct the device. I know a lot of Engineers, and they know a lot more engineers, but my current problem is that I don’t know for sure what to ask them to help me make / develop.

Another possible option might be a aimable EMP gun. The beauty of this device is that the cruiser ECM chip will get fried, the radar gun will go up in flames, and the radio will fade to black. If you can’t be clocked, chased, or “cut off at the pass” by a radio, it has all the trappings of a wonderful day. I hear a lot about this type of device, don’t really know it’s application limitations, feasibility, etc. Does this type of device really exist in a portable, effective, sufficiently powerful form?

Thanks in advance for the reply / info /help/ advice,
Thanks again,& email me directly if you like at mmrmcthomas@aol.com


you seems to be with much knowledge , so I want to ask you about infrared detectors , the sensetive one that could detect a vehicle engine heat from 400 or 500 meters


— Posted by Morgan Thomas on 8:59 pm on April 4, 2002

Thanks for the compliment, but I don’t think we are talking about the same thing. Doppler radar is the one that used for speed detection. The infrared spectrum can be used to detect heat through it’s radiant heat waves, but I’ve never heard of it being used for speed detection. The principle  behind doppler speed detection is something called “Doppler Shift” when something is moving toward you the waves are compressed and this changes their frequency according to that rate of compression ( moving away is just the opposite) It’s like sound waves. Infrared waves essentially change color /frequency based upon the heat energy they possess ( It’s more like radiant heat energy in the infrared spectrum, more like light waves). One measures speed by virtue of electronics, a known frequency being emitted. and a calculated measurement of it’s rate of compression when it bounces off a object ( like a car). The other measures sometihing that is emitting it’s own waves, has receptors that are sensitive to the infrared spectrum,and produces a picture based on the radiant heat value to correspond to the different heat values .  


— Posted by Silver Bullet on 10:27 pm on April 5, 2002

I read that you can take certain radar dectors and convert them into a jammer by reconfiguring them into a transmitter. Is this possible?


— Posted by Zambosan on 1:47 pm on April 9, 2002

No.  Radar detectors pick up police band electromagnetic radiation and report it’s strength.  A whole other set of circuitry and power antennae are required to transmit.


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