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.
We found this circuit in a documentation from the 50s. It is based on CK722 germanium transistors. The...
Found in an English publication from the 1960s, this circuit uses period components, including the...
This oscillator can generate 2 to 10 MHz signals and was found in an American 1980s documentation. The...