This circuit from an old documentation includes the power supply for the 117 V power grid. It can be adapted to other networks by changing the 10k resistors.
Found in an American documentation from the 1960s, this circuit uses transistors from the time. The...
This receiver with two common JFETs was found in an old English documentation. The phone is...
With a load of 35 ohms this amplifier provides a power of a few tens of milliwatts, but we can use an...