| 摘要 |
PURPOSE:To eliminate the need for conversions corresponding to different broadcast systems by providing a high-frequency modulation part and a high-frequency booster part within a container and switching a tuning circuit of the modulation part with a filter part of the booster part in case the broadcasts of different systems are received. CONSTITUTION:The sound signal is modulated at a high-frequency modulation part of a figure (a). When an electronic switching circuit 16 is off, a switching diode 15A is turned off. Then the center frequency f1 of a 1st broadcast system is decided by a tuning capacity 11 and a coil 12. At the same time, only a switching diode 15B is turned on when the circuit 16 is off with a booster circuit of a figure (b). Then a TV signal is supplied to a filter part 17 in response to the 1st broadcast system. In case the circuit 16 of (a) in a figure 4 is on, a diode 15A is turned on and a center frequency f2 of a 2nd broadcast system is decided by the capacity 11 and the coil 12. At the same time, a TV signal is supplied to a filter part 18 needed for the 2nd broadcast system when the circuit 16 is on also in a figure (b). |
