Added a capacitor C_4 respectively, two initial twin T networks in the antialias filter of DFS-V seismic acquisition system greatly differ from symmetric twin T network in transfer characteristic.

• DFS-V数字地震仪去假频滤波器的前两级双T网络中,由于C_4电容的存在,使得对称双T网络的传递特性发生了重大变化。