A radio receiving circuit provided with a search tuning mechanism. A broadcasting radiowave signal is received during a search tuning operation, and a shift amount of frequency produced in frequency of an intermediate frequency amplifier output is experimentally determined within an inertia self-travelling...http://www.google.com.hk/patents/US4792988?utm_source=gb-gplus-share專利 US4792988 - Radio receiving circuit with a search tuning mechanism
