This circuit was found in Philips documentation from 1967. The components are of the time, being transistors like BCY38 for TR1, BC108 for TR3, and others depending on currents.
This high Q “rejector” or notch filter rejects signals whose frequencies are in the range...
This circuit was found in documentation from the 90's, having an LC compensation network. The...
This two-transistor circuit was found in the January 1994 issue of Electronics Now magazine....