This 1974 circuit uses two 555 integrated circuits in a very traditional configuration. The circuit can be powered by voltages from 9 to 12 V and for greater volume an amplifier stage can be added.
This circuit in a receiver that allows the capture of distant stations with short waves. The...
This simple circuit of low power with an LM386 includes the highly sensitive audio preamplifier...
This circuit is from old documentation but can be applied to modern equivalent components. The...