Found in the February 1983 Radio Electronics magazine, this circuit uses a FET and has good gain at the frequencies determined by the components. The FET is any general-purpose FET.
This shield circuit can serve as a basis for a digital mixer or simply for a switch without noise...
This shield or interface makes it possible to control power loads connected to the power grid from...
Based on an LM36000 OTA this circuit was found in the July 1988 issue of Radio Electronics...