Comparison Sound Quest 520 vs Whistler XTR 500

The wavelength of laser radiation that the radar detector is capable of detecting. Laser radars (lidars) are increasingly used along with conventional ones, and the ability to work with them is highly desirable for a radar detector. Modern detectors can be designed for both a specific wavelength and a specific range; the second option is more advanced, because. gives more guarantees, but also costs more.

The types of pulse signals that a radar detector can detect. Modern police radars, usually, do not use a constant exposure mode, but short (fraction of a second) pulses, and even if the detector supports the appropriate range, it does not mean that it will be able to detect a pulsed signal in this range.

Here are the main types of such signals that are relevant for modern radar detectors:

— Instant On. Name for the general mode of operation used in most modern police radars. A radar operating in this mode emits radio waves only directly when measuring speed, for a very short period (less than a second).

— P.O.P. Mode of operation used primarily in K- and Ka-band radars (see above). Provides a single pulse of extremely short length — about 0.07 s.

— Ultra-K (K-Pulse). The standard pulse mode of operation of the radar in the K band. Unlike POP, it provides measurement using several pulses and a longer total measurement duration — up to 0.4 s. Thus, the requirements for detectors under Ultra-K are somewhat softer than under POP, however, for correct recognition, support for this mode must still be claimed directly.

— Ultra Ka. The standard pulse mode of the radar in the Ka band. In terms of its main features, it is completely similar to the Ultra-K described above, differing only in operatin...g frequencies.

— Ultra Ku. The standard pulse mode of the radar in the Ku band. In terms of its main features, it is completely similar to the Ultra-K described above, differing only in operating frequencies. It occurs very rarely, due to the gradual exit of the Ku range itself from use (for more details, see "Ranges of operation").

— UltraX. The standard pulse mode of the radar in the X band. Like the X band itself, this mode is considered obsolete and is provided more “just in case” and as a tribute to tradition than for practical reasons.

— Protection against VG-2. VG-2 is the name of the direction finder device that determines the presence of a radar detector in a car by the accompanying radiation from the superheterodyne (see "Receiver type"). Such devices are used by the police in countries where radar detectors are prohibited by law. Accordingly, protection against VG-2 makes it possible to determine the presence of this device on the road (by the direction finder's own radiation) and automatically turn off the superheterodyne in order to avoid detection of the detector and unpleasant communication between the driver and the inspector. In general, this function is very ambiguous: where it is relevant, the radar detectors themselves are illegal, and in countries where there is no ban on such devices, it is better to turn off the VG-2 protection to avoid false positives from interference.

— Protection from Specter. Protection against detection of a radar detector by a direction finder of the Specter type. These direction finders are completely similar to the VG-2 described above, but they have one unpleasant feature: the lack of a fixed operating frequency. In fact, this means that it is impossible to detect the "Spektr" in advance, and you can protect yourself from it only by shielding the local oscillator and other methods aimed at reducing the intensity of radiation from the radar detector.

— False positive filter.... A system that prevents the radar detector from being triggered by extraneous interference that is not related to police radars. Usually, the filtering of such interference is carried out by reducing the sensitivity of the receiver, as well as by electronic filters that distinguish the interference from the radar pulse due to signal features. Some models may also provide maintaining a database of false positives using GPS coordinates: at the first trigger, the point is entered manually by the driver into the database, and if after that interference is recorded in this place several more times, the radar detector finally “remembers” the point of interference and does not respond to her.

— Signature recognition. Support by the device of signature recognition of signals of a radar. Its principle is that the device does not simply react to the presence of radiation in a particular range (as with conventional recognition), but analyzes this radiation and determines whether it corresponds to the characteristic features (signature) of the radar. Thus, the number of false alarms is significantly reduced: the device gives a signal only when it detects the characteristic radiation of the radar. In addition, this technology even allows you to recognize specific radar models and inform the driver about it. Among the disadvantages of signature recognition, in addition to the increased cost of radars, one can note a reduced (on average by 10–20%) response speed. In addition, the signature memory is limited, it usually contains data only from the radars of a certain region. So when buying a device with this function, it is worth considering for which region the radar detector was originally intended.

— Anti-sleep function. A safety system that prevents the driver from falling asleep at the wheel. When anti-sleep is turned on, the radar detector beeps from time to time, to which the driver must respond — usually by pressing a button. If the button is not pressed, an alarm is activated, which also plays the role of an alarm clock.

— SWS mode. The ability of the radar to receive SWS signals — a warning system that warns the driver about approaching an emergency section, a narrowing of the road, the scene of a traffic accident or roadworks, etc. For such alerts, special beacons installed by road services are used. Note that in the CIS countries the SWS system has not yet received distribution.

— Auto mode. The presence of an automatic mode in the radar detector, in which the device independently captures the level of ambient interference and determines the measures necessary to compensate for them (reducing sensitivity, applying filters). Operating in Auto mode is more convenient for the driver than manually switching between City and Highway (see below). On the other hand, this mode is less reliable: even the highest quality automation is not always able to recognize changes in environmental conditions, and only human participation can give a full guarantee.

— Route mode. The presence in the radar detector of a separate mode "Track". This mode is intended for driving on roads outside of settlements; in such places there is little extraneous interference, and the sensitivity of the receiver can be increased in order to guarantee not to miss the signal of the police radar

— City mode Availability of a separate “City” mode in the radar detector, designed for driving within large settlements. In large cities, there are many sources of electromagnetic interference that can lead to false alarms; to avoid such operations in the "City" mode, the sensitivity of the receiver is reduced and noise filters are turned on.

— Setting the speed limit. The ability to set a speed limit on the radar detector. The meaning of this function is that when driving at a speed not exceeding the set one, the device does not give sound signals and does not distract the driver once again (although the light signals or notification on the display are still displayed). If the limit is exceeded, the radar detector will “scream out loud” when triggered. The best way to use this feature is to set the speed limit according to the current road limit. Typically, a GPS module is used for speed tracking (see below).

— Adjust the brightness of the display. Ability to change the brightness of the radar detector display. This function allows you to optimally adjust the screen to the characteristics of the environment. For example, on a clear sunny day, the brightness should be maximum, otherwise the image on the screen cannot be seen normally; and at dusk it can be lowered so as not to tyre the eyes and not impair the visibility of the road.

— Mute. The ability to turn off the sound alerts of the radar detector. This feature will be very useful in situations where loud sharp sounds (and the signals of modern detectors are usually exactly like that) are undesirable — for example, if a small child is sleeping in the cabin.

— Voice notification. The ability to "voice" the sound notifications issued by the radar detector using voice. Such notifications are more convenient than traditional sound signals (beep, buzzer, etc.), they usually provide extended information — for example, the device can say aloud the type or range of the radar. Such data can also be displayed on the display/indicators; however, voice guidance keeps the driver focused on the device.

— Disabling ranges. The ability to disable individual operating ranges of the radar detector at the request of the user. This function allows you to optimally adjust the device to the situation in a particular country: if the range is not used by the local police, it is better to turn it off to avoid false positives and to speed up the detector.

Type, more precisely — the principle of operation of the receiver used in the radar detector. Initially, classic direct amplification receivers were used — simple, inexpensive and not giving extraneous radiation, which completely excluded the detection of such a radar detector by police technical means. However, direct amplification does not achieve high sensitivity and is not well suited for multi-range devices. Superheterodyne receivers are deprived of these shortcomings, thanks to which they gradually replaced classical tuners and are by far the most popular option. However superheterodynes are noticeably more complicated and expensive, and besides, they are easily fixed at a distance by technical means like VG-2 or Specter (for more details, see "Functions").

The signal processing method used by the radar detector.

Initially, inexpensive radar detectors used analogue processing units, digital ones were installed in advanced equipment, and digital-analogue "hybrids" were a compromise option. However, today, thanks to the development and cheapening of technologies, the vast majority of models use digital processing — it is the most accurate and provides the most opportunities.

The current nominally consumed by the radar detector during operation. Usually, with a regular connection to the cigarette lighter socket with the engine running, this parameter does not play a special role — even the most advanced models do not “eat” so much that this noticeably affects the operation of the on-board network. In fact, current consumption data may be useful only in some specific situations — for example, battery operation.