| 摘要 |
An intercarrier sound system is provided in which a single transistor is used as both the intercarrier sound mixer and a sound I.F. amplifier. The transistor has an input circuit which includes its base-to-emitter junction, and an output circuit including its collector electrode and one of its base and emitter electrodes. Picture and sound carrier signals are applied to the transistor by way of the input circuit and are mixed across the base-to-emitter junction of the transistor. Means are provided at an electrode of the transistor common to the input and output circuits having an impedance which varies inversely with frequency. The variable impedance means causes the amplification provided by the transistor to vary directly with frequency over a band of frequencies including the video signal and the intercarrier sound signal frequencies. |
