Radar detectors don't keep you from getting speeding tickets.
If you are going faster than everyone else then the cop will turn his radar on while pointing at you and he will clock you at the same time your radar detector starts beeping. Bam, speeding ticket.
if you are going faster than everyone else you are automatically wanted (kinda like the jail server.. lol) even if the cop doesn't use his radar you are probably getting pulled over and more than likely getting a speeding ticket.
The only way radar detectors actually stop you from getting tickets is if someone else near you is getting clocked
* plus, simply having a radar detectors is like telling the cops you like to speed and not get caught (not to mention they are illegal and quite a few states)