[Official] What's the Best Radar Detector?

winnre

There was a company who picked up on the police repeater frequencies. many patrol cars will receive the radio signal and then repeat it to the patrolman's handheld radio, This signal is what gets picked up by the detector, and as long as there is radio traffic you have something to pick up.

Here in California it is a little known fact that it is illegal to have a police scanner in the car unless you have a HAM radio license. All you are doing is picking up the existence of this frequency anyway, not the traffic.