after all my tests.....the CB STILL is the single most effective device to avoid speeding tickets. The police scanner does zip, and most departments use encrypted channels that cannot be picked up by scanners anyway.
The two times I have gotten pulled over for speeding, one, the guy was hiding and using marks on the road and a stopwatch to calculate my speed (so, radar detector would've been useless), and another time the radar detector never even went off.