| 摘要 |
PURPOSE:To facilitate adjustment and to eliminate errors by making matching between impedance of at least two tuning circuits that selects frequency signals of different frequency band and impedance of an antenna by the capacity adjusting section of a trimmer condenser. CONSTITUTION:The maker sets the capacity adjusting section 15' beforehand at mechanical center so as to make the capacity of the trimmer condenser 15 the central value in the variable range. A fixed condenser 137 selected to have a capacilty that almost tunes with the central value of the trimming condenser 15 is provided to match the impedance of a tuning circuit 13 for medium waves and impedance of an antenna. Further, the capacity of a trimmer condenser 141 is preparatorily adjusted to match the impedance of a tuning circuit 14 for short waves and impedance of the antenna. The user adjusts the capacity of the trimmer condenser 15 to match the capacity of connected antenna and impedance of tuning circuits 13, 14 by operating the capacity adjusting section 15'. |
