Found in documentation from the 1980s, this circuit can have several adaptations to use modern transistors and LEDs instead of the lamp. The power supply voltage can also be changed.
This circuit is from the LM107 manual, which is a component of the 80s. The circuit can be adapted to...
This small audio amplifier circuit in complementary symmetry was found in the 1974 Mullard...
The coil of this receiver consists of 100 turns of wire 38 to 30 in a ferrite rod and the...