| 摘要 |
PURPOSE:To judge whether or not the service is received accurately and quickly by detecting and displaying an electric field strength and displaying it when the electric field strength does not reach a setting level and the service is not available. CONSTITUTION:An envelope is extracted from a reception signal by an envelope detector 28 via an antenna 25, a switch 26 and a reception section 27 and after the median of the envelope is extracted by a median detection circuit 31 composed of a comparator 29 and an integration circuit 30, the electric field strength corresponding to the identification number of each area is stored in a memory 32. Then a level deciding circuit 33 outputs an electric field strength in an area having the highest reception electric field strength among talking areas and an electric field strength of a message area. The output is selected by using a mode changing over switch 14 and the result is inputted to an electric field strength display section 12. Thus, whether or not the service is available is quickly and accurately judged. |
