Been testing out my XTR-690se in and around Bakersfield, CA. Only encounter of note was a Livermore PD K9 unit tagging me from behind with I/O at the I-5 and 99 split (just North of the Grapevine). Strange part was, a frequency was NOT shown on the display. Just a quick near full strength Ka alert. I'd estimate I was first alerted when the LEO was about 500 feet behind me. I ended up following him for a few miles after he passed me and kept getting brief but strong Ka alerts. Eventually I got a 35.5 alert as I took my exit and pulled off the highway.
Not sure what he was doing tagging people with I/O since he wasn't anywhere near Livermore. Maybe he was bored and trying to pass the time? I-5 is a pretty boring stretch through the Central Valley.
I'm wondering why a frequency wasn't displayed. Maybe his quick trigger I/O was too brief to register a frequency. Either way, I am DEFINITELY paying more attention to Ka alerts that don't display the frequency. Better safe than sorry.
Highway, X off, POP off, Filter, RSID (KaMAX is off), LSID
Also note that I had JUST merged onto the freeway when the detector originally alerted. So the 500 foot detection range is merely a data point. I'd have no way of knowing whether or not the 690se would have picked it up had the LEO been further back.