From my understanding door openers, alram systems, etc send out K falses only. There is one particular spot near my house which just started giving me false Ka alerts everytime I pass through. The only thing that it could be is a little post office that sits a bit off of the road. Like I said, it is a Ka alert at a 34.7 frequency. It has me at a loss. What could it be? I may be wrong about the door openers and what not sending out K alerts only, I read that on this forum somewhere I believe.