I saw a Ka band antenna (dual) cop cruiser in lexington parked in a empty parking lot talking on the phone. I decided to go over and speak to him. I pulled up next to him and he rolled down his window I asked him if that was Ka band and he said yes. I asked him to turn it on and he did took the x50 about 5 secs before it went to full alert ( i guess the Ka gun was going through a self cal or something like the detectors do) I asked him if it had instant on he said it did. Very few of our cop cars run on Ka band. From my understanding a cop car cannot pull you over based on INSTANT ON speed readings. Is this true? Is POP and Instant on the same thing? My detector just said Ka with 9 bars it didnt say POP KA. Pop was turned on. cop was very nice and didnt care i had a detector he just said they dont work lol. I was like this one better.