There was some silent because of my participation in serious project. And now I try to compose an application for patent. It’s my favorite CPC (Cooperative Patent Classification) section G01S03/40 – “Radio direction-finding appartus using orientation of a single directivity characteristic to produce maximum or minimum signal”. In my opinion, it’s the most suitable section for mobile direction-finders. I found just single invention (US8456296, priority from 2009, by Radio System Corp), which looks similar to my design. The invention is named “Assisted direction finding apparatus”.