This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
Suggested by General Electric in 1980s documentation, this circuit makes use of PUTs that are not...
This circuit is from a manual of linear integrated circuits of the 80s. The operational is of the...
This circuit for several frequencies was obtained in an American documentation from the 90s. The...