This filter has a regulated source configuration. It can be implemented with almost any operational amplifier. The formulas for calculating the components are attached to the diagram.
Found in an English documentation, this circuit provides a 50 Hz signal according to the local...
This circuit provides 15W per channel and can operate with a single power supply. The circuit is...
This preamplifier for the 6 or 2-meter range was obtained from an American documentation from the...