| 摘要 |
An equalizing network for attenuation/frequency characteristic equalization. The equalizing network comprises a plurality of attenuation branches B1 to B8 which are operative in mutually different frequency sub-bands covering a wide frequency band. A negative feedback amplifier 10 has its negative feedback factor set for each frequency sub-band by means of a potentiometer P1 to P8 which is part of the relevant attenuation branch. Resistors 17, 18, 19 and 20 form the negative feedback circuit for the amplifier 10 and provide voltage-dividing, to alter the feedback factor and thus the gain of the amplifier 10, for the individual frequency sub-bands as determined by the potentiometer settings. Attenuation branches pertaining to non-adjacent frequency sub-bands are grouped together in two groups X and Y to obviate the need for separation amplifiers for each attenuation branch. |
