This circuit was found in a Popular Electronics from the 90s. Its purpose is to disable the output of an FM or VHF receiver between stations, preventing the reproduction of hiss.
We found this circuit in a 1998 publication. The circuit has controls for both frequency and...
This circuit for conventional lines was obtained in a 1996 documentation. The circuit uses common...
This is the conventional version of capacitance multiplier with operational amplifier that appears in...