| 摘要 |
PURPOSE:To use a circuit having the same circuit constitution as two and four heads constitutions, by switching the gain of an amplifier circuit mixing and amplifying a video FM signal to be recorded and a low frequency conversion color signal with the operating mode. CONSTITUTION:A video signal FM-modulated is inputted to a terminal t1 and adjusted to a prescribed level at a semi-fixed resistor RT1, and applied to the base of a transistor (TR) Q1 mixing and amplifying signals. Further, the color signal converted into low frequency is inputted to a terminal t2 and applied to the emitter of the TRQ1 via a semi-fixed resistor RT2. The mixed and amplified video FM signal and a low frequency conversion color signal are outputted from the collector of the TRQ1 and applied to video heads H1-H4 of exclusive modes via a recording amplifier 2 and a head changeover switch SW3. The gain is changed by changing a signal t3 to the base of a TRQ2 at a long time mode and the standard mode. |
