Well this kind of surprised me because it's a nice day and I was rocking my tunes when it happened, so I didn't quite know wtf was going on for a second. I was coming up Prune Hill and nearing a very sharp curve in the road. I saw two cars come around the corner from the other direction and I got a Ka hit (3 lights) right there which was promptly J'd out. Like I said, I didn't know what happened for a second because I had never heard the J tone. I usually just glance down at the display to check the arrows, but I saw the J flashing and figured it out real quickly. Unfortunately, I was paying attention to the sharp curve approaching and did not think to look in the cars for a detector, but I'm assuming that's what it was.
My city uses only K band but the sister city uses Ka, so I thought it might have been the other city's radar. But nothing was found. Overall, it worked like it was supposed to and actually surprised me. I drive on the freeway a lot and have seen a lot of Cobras in town and on the highway, but have never seemed to get a false alert from one. I have POP on in case anybody is wondering.