A notch filter suitable for the rejection of the 50 hertz pick-up

In industrial areas the 50 Hz pick-up creates a nuisance in recording the seismic data. This a.c. line pick-up should be prevented from entering the seismic amplifier if it is desired to record the best seismic data. In this paper design of a 50 Hz notch filter is given. This notch filter is suitable for eliminating the line pick-up. It gives an attenuation of 4S db at 50 Hz. It has a 6db band-width from 46 Hz to 55 Hz.