Road Patrol XK Superheterodyne Radar Detector (220-1621) Operation Faxback Doc. # 17809 POWER SWITCH Press the power switch to turn the detector on or off. When you first turn on your detector, it performs a self-test on all its circuits. This test takes about 6 seconds. During this test, alert tone sounds and/or the warning indicator lights. You can set the tone volume during the test. After the test confirms that the unit is operating, the tone stops and the indicator turns off. The green power indicator should remain on. If the green power does not stay on, or if the unit turns on and off or the alert tone sounds often for no reason, check the connection of the power cable at both ends to be sure it is not loose. SENSITIVITY SWITCH In highly populated areas, there are many devices that use X-band frequencies for motion detection or intrusion alarms. These devices can trigger an alert on the detector. You can adjust the detector's X-band sensitivity to help avoid these annoying false alarms. Set the HWY/CITY switch to CITY to mute most of these weaker signals. When you drive on the open road, set the switch to HWY for full X-band sensitivity. K-band sensitivity is not adjustable-this assures optimum detection of "instant- on" radar signals. VOLUME CONTROL Turn the volume control to adjust the alert tone's volume level as desired. BUZZER/BOTH/LIGHT SWITCH When the unit detects a radar signal, it alerts you visually, audibly, or both. Choose the desired setting of the BUZZER/BOTH/LIGHT switch. BUZZER = Only sound alert LIGHT = Only visual alert BOTH = Sound and visual alert The rate of the beeps and/or flashes increases as the radar signal strength increases. SIGNAL STRENGTH METER The signal strength meter's five indicators provide a visual indication of the strength of radar signals-the more indicators that light, the stronger the radar signal. RADAR DETECTION Two criteria determine the performance standard of your radar detector- selectivity and sensitivity. Selectivity refers to the quality of the warning signals and the unit's ability to reject certain signals/ frequencies. Sensitivity refers to the minimum signal strength needed to produce an output. Together these two factors make up the "superheterodyne" technology used in radar detectors since 1976. Originally, conventional radar detectors needed a direct signal to register the presence of police radar. Super- heterodyne technology is sensitive to both direct and indirect incoming radio frequencies and electronically processes these signals to verify their authenticity. Think of it this way. A water glass is your radar detector and the water is police radar. It takes a certain amount of water (radar) in the glass to over-flow (activate the radar warning signal). But the Micronta Road Patrol XK Radar Detector has a pre-loaded signal (full glass of water), so it takes only one drop of water to overflow or set off the warning. The detector is so sensitive that even a fraction of police radar scatter (energy) will activate it. SCATTER The term "effective working distance" means that a vehicle is close enough to reflect the transmitted radar signal with enough strength to give a reading. But the signal itself travels far beyond that point. This portion of the signal is called "scatter" and can be present several miles from the police radar unit. Your radar detector can pick up these scatter signals, but the signals returned to the police receiver unit are too weak to accurately register your speed. For example, in the drawing at right, Vehicle B (with the Micronta Road Patrol XK Radar Detector) receives warning of police radar far in advance of Vehicle A, which uses a conventional radar detector. THE SCIENTIFIC PRINCIPLE Police radar operates on a scientific principle called the Doppler Effect. When the narrow microwave beam strikes a moving object, such as your car, a signal is reflected off the vehicle. The frequency of this beam increases or decreases depending on the speed and direction of the object it hits. The police radar unit compares the reflected signal with the original signal and electronically computes the difference. Then, the speed of the vehicle appears on a digital readout display. RANGE The maximum operational range of the best police radar is about 2,500 feet for automobiles and 3,500 feet for large trucks. Police radar uses super-high frequencies. As the signal travel, they widen and become conical - like a headlight beam at night. Even when your car travels on a curving road, the conical transmission of the police radar will fan out enough to encounter your car. Three factors affect police radar efficiency: Microwave signals travel in straight lines and are, therefore, limited to line-of-sight use. (See the drawing below.) The reflected signal is much weaker than the transmitted one. The transmitted signal can reach as far as five miles. But the approaching vehicle must be close enough to reflect the signal with sufficient strength to be detected and monitored by the receiver portion of the police radar unit. Besides checking speed with radar, a police officer must be able to identify the speeding vehicle in order to give a ticket. And beyond 1,700 feet, visual accuracy is questionable. NOTE: Based on the above conditions, stationary police radar is normally adjusted to an "effective working distance" of up to 1,500 feet. Moving radar is adjusted for up to 2,000 feet. SPEED DETECTION Police radar is extremely accurate to one-tenth of a mile per hour provided the vehicle is within range and is moving directly toward or away from the transmitted signal. The following illustrations illustrate more clearly the principles of radar detection. Radar does not pick up either vehicle A (outside effective working distance) or Vehicle B (out of line-of-sight). Police radar will indicate an inaccurate speed (always reduced) when the signal reflects from a vehicle at an angle. A vehicle traveling at a 90 degree angle to the radar beam will reflect zero speed. NOTE: Measurement of speed for a vehicle traveling at an angle to the radar beam is reduced from the actual speed as the angle widens. True speed is measured only when the vehicle is moving directly toward or away from the radar beam. (WL/all-11/13/95)