| 摘要 |
PURPOSE:To improve the operability of a reproduction equalizer by switching a reproduction equalizer to another one having the suited characteristics in a reproduction mode. CONSTITUTION:The FM-modulated video signals are applied to a reproduction equalizer 3 from a video head 1 as the input signals. Here the output that varies its output level against the frequency (f) based on the S-shaped characteristics is obtained by a frequency discriminating circuit 11 consisting of a buffer amplifier 5, a phase shift circuit 26, a mixer 27 and an LPF 28. A comparator 14 receives the voltage Vvef of a reference voltage source via a variable resistor 30 and compares the averaged levels of voltage with each other. Thus the comparator 14 produces the output of a prescribed level in a signal reproduction mode by a high band system for example.
|
