Amplifier for crystal radio earphone

This is a crystal radio amplifier for amplifying the output to a crystal earphone or telephone receiver earphone. It uses a single transistor and is very simple to make. This circuit is by Charles Wenzel and originated from his website here.

Amplifier circuit. The crystal radio used for example purposes is the crystal radio made from scraps here.

The main components mounted on a breadboard.

The complete amplifier.

The amplifier attached to a crystal radio.

If you did want to try making the above circuit on a breadboard as in the above photo, then the following is a diagram showing how I arranged all the parts. The videos below use this same arrangement.

Diagram for the ampifier circuit on the above breadboard.

Videos with details of the amplifier construction

The following are two construction videos of the making of this amplifier.

This first one includes:

• discussion about the parts,
• how to use a breadboard,
• circuit diagram and how to use it to fill in the breadboard,
• a little about electrolytic capacitors,
• a little about transistors,
• demonstration of it working, and
• a little about how the circuit works.

This second one shows every step of putting the circuit together on the breadboard and then connecting it to the crystal radio.