[avi8torny]

This is an easy one. When you go by, and they go from the "standby mode" to the "instant on" mode you acknowledge to them that you have a detector by the nice bright red brake lights you display or the fact that the car behind you that is following way to close for the speed you are traveling, almost rear ends you. Absent being behind you, when they see the target display go from the "instant on" speed that the unit displays to a lower speed very quickly, it's pretty evident that you have some type of electical warning device or maybe you just have great reflexes. Remember though that RADAR is a verification of what the officer observes, not the other way around. Just like braking at the track before a turn, it's easy to see the nose of the car dive.

BTW, no detector will defeat the "instant on" device with an operator who knows what he or she is doing. It will help defeat a radar operator who constantly "pollutes" the airwaves with whatever band his/her unit operates on.

Haven't seen many radar detector/detectors in state's that allow their use other than with the Commercial Vehicle Enforcement Units. They have them because operating a truck in NY over 16,000# with a detector is illegal.