Road Patrol XK Superheterodyne Radar Detector (220-1621) Hints and Tips Faxback Doc. # 17810 The False Alert Suppression Technology (FAST) circuit in the radar detector filters out most of the extraneous signals from other radar detectors on the road. This circuit does not reduce the radar detector's ability to receive traffic radar signals. Because of the high sensitivity of the radar detector, it can detect energy from devices operating on the same frequencies as police radar (such as automatic door openers, railroad car counting systems, and security devices). It's impossible for the radar detector to distinguish between police radar and other signals transmitted on the same frequency. Not every police car you see is equipped with radar. And not all radar-equipped police cars have their radar units on all the time. Do not expect the radar detector to sound an alarm every time you see a police car. The radar detector might occasionally give you a late alert. This is because radar signals are highly directional, and the unit's ability to detect them is sometimes affected by the way an officer angles a radar gun. The reaction of the detector can also be affected by the way an officer turns the radar on and off. The radar detector is a driving aid, not a license to speed. Use it with common sense. (WL/all-11/13/95)