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Why do I need a radar detector?
  Have you ever gotten a speeding ticket? It's embarrassing and it's expensive! In addition to the high cost of the traffic fine, you also have court costs, inconvenience and the impact on your insurance rates.

   More than 100,000 active Traffic Radar guns are deployed across the USA.
Since the mid 1970's, radar has served as the tool of choice for traffic speed enforcement. More than 100,000 radar units are in use by police agencies in the United States, and they account for more than 30 million speeding tickets each year. In fact, there are so many radar guns on the road, your speed may be monitored when you least expect it!

   More than 15,000 active Traffic Laser guns are deployed across the USA.
City police on urban, multi-lane roadways use the most laser guns, and the use of laser guns for speed monitoring is increasing. In fact, your risk of encountering traffic laser is escalating every day.

How radar detectors work

This is CNK6080 radar detector.

  Think of a radar signal as a beam of light from a flashlight. When you shine a flashlight at an object, your eyes perceive the light reflected from the object.

  Now imagine yourself as the object being illuminated. You can see the light from the flashlight from a much farther distance than the person with the flashlight could ever hope to see you. That's because the beam loses energy over distance. So while the beam has enough energy to reach you, the reflected light doesn't have enough energy to travel all the way back to where it started.

  That's the idea behind radar detectors. Police radar units transmit a series of radar pulses and calculate your speed based on how long it takes two consecutive pulses to reach the radar gun after being reflected off your car.

  Radar detectors look for radar "beams" and find them before they can "illuminate" you. Detectors use superheterodyne design to "see" radar beams even though they may not be strong enough to reflect back to the radar gun. This design sends out a signal which mixes with any incoming radar to produce a lower frequency that can be more easily detected. It also allows detectors to detect beams around curves or over hills, and it extends their range straight ahead.

Different Types of Radar

   X-Band Radar: 10.5 to 10.55 GHz ! Dating from the 1950s, X-band radar is the easiest to detect because of its lower frequency and higher power output. Depending on terrain, temperature and humidity, X-band radar can be detected from a distance of 2 to 4 miles, yet it can only take accurate readings of speed from a distance of 1/2 mile or less.

  Unfortunately, police radar is not the only source of X-band signals. Garage door openers, microwave intrusion alarms, microwave towers, and other high-tech equipment can fool a radar detector into giving off an X-band alert. Filters and redundant sampling are used to combat this "falsing."

K-Band: 24.05 to 24.25 GHz

   K-band, the most common type of police radar, made its appearance in 1978. The first K-band hand-held radar guns could only be used from a stationary position. Later, a "pulsed" version was introduced that could be used from a stationary or moving vehicle.

  K-band radar waves have a relatively small wavelength so they are more easily absorbed by water molecules in the air. At the power level found in police radar guns, K-band has an effective clocking range of about 1/4 mile. Depending upon terrain (around a corner, over a hill, etc.), K-band waves can be detected from a range of 1/4 mile to 2 miles.

  K-band guns also have what's known as "Instant-On" radar. This keeps the transmitter in "hot standby" mode, ready to be activated by an officer when the target is within 200-300 yards.

  If it's been aimed at you, your speed has been measured by the time the detector alerts you. If it is being used to target vehicles ahead of you, your detector may provide a warning in time for you to slow down and avoid a ticket.

Ka Photo Cop and Ka Wide-Band: 34.2 to 35.2 GHz

  In 1987 the FCC allocated a frequency on yet another band, Ka, for police radar use. With that came the introduction of photo radar (also known as "photo-cop"). The photo-cop system works at 34.3 GHz and combines a Ka-band radar gun with an automated camera.

  A vehicle approaching at or above a predetermined speed will trigger the camera. The photo shows the front of the vehicle, license plate, driver's face, the date, location, and time. The unit can clock and photograph up to 200 vehicles per hour. Alleged speeders are not stopped. The film is processed and a ticket is mailed to the registered owner of the vehicle, ordering him or her to pay the fine or appear in court.

  Photo-cop's effective range is 120-300 feet and it transmits a continuous signal which is a plus for radar detectors. The distance at which it can be detected varies depending upon a detector's Ka-band sensitivity. Better detectors can typically sniff out a photo-cop system 1/4 to 1/2 mile away.

  Only a handful of cities use photo radar. Industry sources predicted widespread interest and expanded use, but that has not been the case. Legal controversies along with prohibitive expense have caused officials to stick with more traditional methods of speed detection.

  The FCC later expanded Ka-band radar use to a range of 34.2 to 35.2 GHz. This became known as Ka Wide-Band.

Ka Super Wide-Band: 33.4 to 36.0 GHz

   The introduction of the "stalker" radar gun raised the stakes in the detection game. Unlike all previous guns, the Stalker can be FCC licensed for any frequency in the Ka-band between 33.4 GHz to 36.0 GHz, and so cannot be picked up by detectors designed only for X, K, and photo radar. Stalker guns are being used in more than half the country.

  In response, manufacturers have developed detectors with "Super wide-band" technology that sweeps all of the Ka-band allocated to radar, as well as providing continued protection against X, K, and photo radar.

Laser Detectors

   With the help of the federal government and the insurance industry, the laser speed gun has found its way into the hands of state and local police in at least half the country.

  The advantages of a laser gun are compelling: the laser light beam is far narrower than a radar beam, allowing more accurate pinpointing of a specific vehicle; and the time needed for capturing a speed reading is less than half a second versus 2 to 3 seconds for radar.

  The drawbacks are also important to note: laser guns are very expensive, they can't be used from a moving vehicle or from behind glass, and accurate aiming requires a tripod or a very steady hand.

  Despite initial claims that the energy from a laser gun is not detectable, it is. And as the laser beam moves away from the laser gun, it widens and becomes easier to detect.

  Vehicle speeds are typically measured at roughly 1,000 feet (1/5 mile); at that distance the laser beam is over 3 feet wide. Many of the laser detectors in use have a working distance of approximately 1-1/2 miles (at that distance a laser gun's beam covers two lanes of traffic).

VG-2 Radar Detector Detection

   You can think of VG-2 as law enforcement striking back against radar detectors. VG-2 identifies vehicles with operating radar detectors on board. Fortunately, all of the radar detectors Crutchfield offers provide some form of protection against this new technology. BEL's "VG-2 Guard" emits an alert and shuts down when a VG-2 unit is sensed. BEL's "Shadow Technology" shields the detector from VG-2 without interrupting radar and laser protection.

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