We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a BC558 and the common 6 V relay, just by using this voltage in the supply.
Found in an Electronics Now from the 1980s, this circuit uses some components that are still...
Unlike the previous one, this circuit uses only one resistor in the base polarization. The...
This circuit has a voltage gain of 30 times and passband of 14 MHz. The circuit is from the 1974...