The LOD/H Technical Journal, Issue #4: File 03 of 10 The Radar Guidebook by Professor Falken ----------------------------------------------------------------------------- Anyone who has driven a car without a radar detector before, has gotten that paranoid feeling that the cops are around radaring. This feeling is not a nice one; it is the feeling that somewhere somehow someone is watching you. In this article I will attempt to explain how radar guns work, what bands the guns work on, why they are wrong 70% of the time, how to employ stealth technology in defeating the radar, and last but not least jamming the radar. RADAR stands for RAdio Detecting And Ranging. A speed-radar gun works under the Doppler theory. This theory is that when a signal is reflected off an object moving toward you, the signal will be at a higher frequency than the initial frequency, this increase in frequency is used to calculate speed. Many of you have experienced the Doppler effect, which occurs when a noise from a siren increases in strength (gets louder) as it approaches and decreases in strength (gets softer) as it moves away from you. Right now in the United States, there are three bands that are Federal Communication Commission (FCC) certified for "field disturbance sensors", known to you and me as radar guns. These bands have proper non-technical names, and all operate in the GigaHertz range. GigaHertz is a measure of frequency; one GHz equals one billion cycles per second. Most frequency modulation (FM) radio broadcasts are made in the 0.088 GHz to 0.108 GHz band, in MegaHertz that is 88 MHz to 108 MHz. The three proper names for these radar bands are: X, K, and Ka. One of the older radar bands is the X band. X band radar is the most commonly used radar band in the United States. X band radar transmits its signal at 10.5250 GHz. The wattage of the radar's signal really depends upon the gun manufacturer. However, most manufacturers agree that a 100 milliwatt signal is "High-Power" and the 40 milliwatt range is "Low Power". The gun's range also depends upon the manufacturer. The average maximum range of a X band gun is 2500 feet. That estimate is based on the assumption that the gun is operating at full-strength (100mw). Most radar detectors give off a false signals on this band due to ultrasonic motion detectors employed by various burglar alarm systems. Large grocery stores also use these to open the doors magically as you walk in or out. Another older band is K band. K band operates on 24.150 GHz and is not as popular as X band, but it is gaining in usage throughout the country. The normal signal strength of K band guns again depends upon the manufacturer, but the ones I've seen all operate at 100 milliwatts at high-power. These guns have a maximum range of 3000 feet, assuming they are at 100mw signal strength. A new type of radar has been introduced and assigned a frequency by the Federal Communications Commission. This new band has been assigned the name Ka and has been designated a frequency of 34.360 GHz. Current Ka technology gives the gun a maximum effective range of 40 to 200 feet. This band was originally made for use with photo-radar. The photo-radar can be set up on a tripod on the side of the road or in the back of a police car. The user then triggers a button when he wants a car in the guns range clocked, automatically taking a picture of the car & license plate. At the time the photograph is taken a date and time is imprinted on the picture. The police keep one duplicate for archival purposes and sends the other to the registered owner of the car along with ticket information and the amount due. This type of system can only work in places that hold the owner of a vehicle responsible for any violations that occur with the car. The legal barriers for photo radar to overcome are extensive, most notably, not giving the vehicle owner due process and the presumption of guilt. There is a system out now for $19.95 that defeats Ka band photo radar. I expect it to be illegal VERY QUICKLY once Ka is more widely used. This little baby slips over your license plate and acts as venetian blinds. When looking straight at the plate it looks like a normal plate with a black frame. However when looking at it from a Ka band Photo Radar's angle it looks like a license plate with a silver streak covering the whole plate, making it impossible to identify. This device is called the Photobuster and is available from most radar detector specialty stores. There are two different types of radar guns. They are Instant-On/Pulse and Constant Broadcasting Radar. The names are self-explanatory, but I will explain them anyway. The constant broadcast radar continually transmits its radar signal, and anything in its path will be clocked. Instant-On & Pulse radars are basically identical, and are both very deadly since they are harder to detect as a threat. The Instant-On gun is really nothing more than an ON/OFF switch for signal transmission. In order to have a pulse gun, all a cop has to do is purchase one with a "HOLD" feature or just turn the gun on when he/she wishes to use it. The "HOLD" feature is simply a button that keeps the gun on but makes sure no signal is being transmitted. No one can detect a gun that is off or in "HOLD" mode. An officer using an Instant-On radar gun will periodically check the speed of the traffic. These samplings can easily be detected and will give the user of a detector prior warning to a Instant On/Pulse activated radar gun. Many detectors on the market today provide anti-falsing circuitry. Falsing is the triggering of the radar detector from something other than a radar gun. One or two detector manufactures make their detectors with GaAs diodes. GaAs diodes are Gallium Arsenide diodes which are a military grade electrical component that helps produce a good signal-to-noise ratio. All new model radar detectors use Superheterodyne technology. Superheterodyne, also known as active technology, amplifies all incoming signals hundreds of times, which makes it more sensitive and selective as to which signals will trigger an alert. Superheterodyne technology also gives out a minute internal radar signal of its own, which can be picked up by older (Pre/Early 1980's) non-anti-falsing radar detectors. If you have a newer model radar detector, this small internally generated signal is no problem to your's or anyone's anti-falsing radar detecting unit. NOTE: In states where radar detectors are illegal (Ex. Virginia, Canada) the police have devices which detect this Superheterodyne signal. Police can then stop you and confiscate your detector. Getting around this police tactic would be to use an early radar detector without Heterodyne/Superheterodyne detection technology. Many compact/shirt pocket radar units are "exclusively made with SMD's". These SMD's are Surface Mounted Devices and contain extremely small resistors, transistors, diodes, and capacitors. Just because a manufacturer uses SMD's, that does NOT make the unit any better than a larger detector of the same age. Cincinnati Microwave Inc., the makers of Escort and Passport say they have the exclusive technology for the detection and anti-falsing of RASHID VRSS technology. RASHID VRSS is actually the Rashid Radar Safety Brake Collision Warning System. It is an electronic device that operates on K band frequencies and warns heavy trucks and ambulances of hazards in their path. About 900 RASHID VRSS units have been prototyped in three states. Since the number of actual operating RASHID units is so minute, I really doubt you will run into one. There are two ways a radar gun can produce an incorrect speed reading. These are known as the Cosine Error and Moving Radar Error. The Cosine Error occurs when a radar gun gives a lower reading than the actual speed of the target. This occurs because the gun can only measure the doppler shift that occurs directly towards or away from the antenna. If the object moves at an angle to the gun, the shift will be lower than if it moves directly at the antenna. Therefore the reading the radar gun gives will be less than the actual speed of the object. The radar reading can be calculated by taking the Actual Speed times the cosine of the incidence angle. So if the target car's actual speed is 50 miles per hour and it is 37 degrees off of the mainline radar signal, the radar speed will be 40 miles per hour. Look: Cosine Error Theory: Actual Speed x Cosine of Incidence Angle = Radar's Shown Speed Cosine of 37 degrees is 0.80 50 MPH x 0.80 = 40 MPH So if you see a radar enabled cop coming head-on towards you it would be a good idea to get into the right hand lane, or further if possible, as this increases the angle and thus lowers your radar speed. The other error is the Moving Radar Error, which occurs only when a police car is using a moving radar gun. A false reading is obtained by the unit because before it can radar you it must radar something along side the road to get the patrol car's speed. Most often, billboards and parked cars are used for this initial patrol car speed calibration. It is susceptible to errors because of the Cosine Error, mentioned above. Once the patrol car has its speed (wrong or not), it assumes that the target's (YOU) speed is the difference between the highest oncoming signal and the patrol speed; but if the patrol speed is lower it will ADD that error on to the target speed. So the target speed (YOU) will read higher than you were actually traveling. Here's the theory and a problem: Moving Radar Theory: Closing Speed - Patrol Speed = Target Speed The ACTUAL speeds for these are: Patrol Car Speed - 60 MPH Target Car Speed - 60 MPH Closing Speed - 120 MPH Due to the Cosine Error the TARGET CAR's speed will cause the gun to calculate a LOW reading for the actual patrol car's speed due to the cosine error. The RADAR calculated speeds are: Patrol Car Speed - 50 MPH Target Car Speed - 70 MPH Closing Speed - 120 MPH Thus you can see how the police car is going to get an incorrect reading. This is a good one to memorize and bring into court for any tickets. It's been recently brought to my attention that there are stealth-bras for cars. From what I understand, the bras actually absorb the radar, and reflect such a weakened signal that the radar gun cannot detect it. I have not seen one of these in person, but from what I have heard they are made out of a VERY DENSE rubber/metal composite. The bra probably traps the signal very much like the F-117/B-2 stealth aircraft do. The material is probably made up of hexagonal shaped cells, the back of the cell being at a slight angle, so that any signal coming into the cell will have to bounce around within the cell before exiting it. The inside of each cell is filled with a radar absorbing material. As the signal hits the back of the hexagonal cell it is bounced around inside the cell through the absorbing material, weakening the signal each time it does so. Upon leaving the cell, the signal is so weak the radar's receiver may not pick up the signal until the target is near enough to give a positive return on the radar screen. When the aircraft is getting closer, within radar range, the signal reflected may be so small the radar's controller may think he is picking up ground interference, a flock of birds or possibly bad weather. The actual radar absorbing material is classified at this time by the government. The actual composite on the car bra is certainly not as good as the actual radar absorption material of the aircraft, but I'm sure it is somewhat similar. Radar jamming is done very much the way any other type of radio jamming is done. You simply overpower the frequency being used with a frequency of your own. Radar jamming/overpowering is ILLEGAL in the United States. To jam a signal all you need is a transmitter, an amplifier and an antenna. To jam a gun using a K band radar (24.150 GHz) all you do is get a transmitter that can transmit in the 20 GHz range and a 10-100 watt amplifier and antenna. Send out a signal at around 24.05 GHz. This signal will make the cop's radar either show a 0 or an incredibly slow speed such as -520. Usually the cop's radar cannot show a negative sign, so it will just be 520. This 10-100 watt signal that you are transmitting will overpower the signal his/her radar sent out and is waiting to receive. His/her gun is only at 100 milliwatts, and you're transmitting at 10-100 watts; its like using a 12-gauge shotgun against a rodent. Where can you get microwave transmission equipment? You can check local electronic shops, satellite stores, Cable TV companies and local television stations as to where they buy their microwave transmission gear. Or you can buy a radar gun of your own, and leave it ON whenever your driving. This will give the cop's gun a very strange reading, most likely zero. If it is possible, once you have the gun bring it to a "corrupt" electronics shop and have it modified for high powered transmission, preferably in the 10 to 100 watt range. Some radar guns have resistors implemented just before the antenna, but just after the amplifier for de-amplification of the transmitter's signal. This means that most guns already have a good (1 watt or so) transmit capacity, but it is suppressed to bring the actual transmit signal to the 100mw area. The owner of the gun only has to know which resistors to take out, then he/she will have a functional high powered gun. If this small wattage does not satisfy you, you may have to purchase a separate amplifier for the gun, and have it wired directly into the radar's transmitter antenna. This modification is expensive not to mention illegal, but then again what the hell isn't these days. I have seen six different types of guns offered from National Radar Exchange. The following are a few major radar gun manufacturers that are sold out of most radar shops. They are: KUSTOM SIGNAL: Kustom Signal HR-12 K Band 100mw signal 2000-3000 foot maximum range $695.00 Kustom Signal HR-8 K Band 100mw signal 1800-3000 foot maximum range $495.00 CMI INC.: Speedgun One X Band 100mw signal 1000-2500 foot maximum range $395.00 Speedgun Six X Band 100mw signal 1000-2500 foot maximum range $495.00 (Since these units are the same, the only differences are things like last speed reading recall, 10 number memory, etc.) MPH INC.: MPH K-55 X Band 40mw signal 1200-2500 foot maximum range $495.00 (Can clock target in 1/2 second, which is exceptionally fast for radar guns) The only differences between the models are their bands and their options, such as a "HOLD" button, last speed recorded etc. I have found these to be some of the top units in the radar detector world currently and are listed as follows: MOST SENSITIVE MOST FEATURES BEST LOOKING MOST RELIABLE SMALLEST -------------- ------------- ------------ ------------- ------------- COBRA 4120 COBRA 4120 Whistler 3SE ESCORT Uniden RD-9XL BEL 944 COBRA 3160 BELL 944 K40 Whistler 3SE Snooper 6000 BELL 944 Uniden RD-9XL BEST VALUE LOUDEST BEST FILTERED ------------ -------------- ------------------ Snooper 4000 COBRA 5110 Snooper 6000 Cobra 5110 COBRA 3120 Other Snoopers Cobra 3168 Whistler Q2002 Maxon RD25 I did not get to see Cincinnati Microwave's new "SOLO", nor BEL's "Vector 3", "Express", nor it's newer "Legend 3." Just because a detector is the MOST sensitive doesn't mean it is the best detector. Because of the sensitivity you could pick up more alarms. What you want is a detector with excellent sensitivity, but good anti-falsing circuitry. I hope this article has given you some insight on how radars work and how their tickets CAN be defeated. Keep safe and sane, Professor Falken Legion Of Doom