This circuit was found in a 1971s English magazine. We can still assemble it using BC548 transistor. The other components are common. The supply voltage of 6 or 12 V depends only on the relay.
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...