| 摘要 |
PURPOSE:To facilitate an adjustment of the deviation of an FM modulator by using a thick-film resistance as a current adjusting resistance for a transistor for control over the oscillation frequency of the FM modulator in a video signal recording circuit. CONSTITUTION:A video signal passed through an AGC circuit and a low-pass filter is supplied to the terminal B of a hybrid IC via a clamping capacitor. The signal is further supplied to an FM modulator 11 by way of a clamping circuit 4, a dynamic emphasizing circuit 5, a main enphasizing circuit 6, a clipping circuit 7, and a current converter 8. In adjusting a deviation, the resistance value of the emitter resistance 10 of a converting transistor is trimmed after the value of a deviation at an FM signal output terminal E is measured, and then a resistance R12 or R13 is trimmed to obtain a frequency which corresponds to the white peak of the video signal, thus making a carrier set adjustment. |
