Electronics Projects

       Project Prep

For years, people attracted to electronics have been drawn to radios. In olden days, radios had big tubes and were the size of a bookcase; today, you can create a small radio yourself by using common electronics components. The radio in this project involves a simple circuit, speaker, and a coil and variable capacitor combo that you use to tune into your favorite station. By working on this project, you discover how to work with radio frequency and amplification to grab radio signals out of the air.

The Big Picture: Project Overview

After you complete this project, you’ll have an AM radio. We know, our favorite stations are on FM, too, but AM (amplitude modulation) was the first method of modulating frequencies used in radio. Building an AM radio is a bit easier to do, so that’s where we start you off.

If you’re dying to discover more about creating an FM (frequency modulation)


radio, check out Basic Radio: Understanding the Key Building Blocks, by Joel Hallas, published by the American Radio Relay League (www.arrl.org).

You can see the finished radio in Figure 8-1.

figure 8-1

Here are the types of activities you’ll be doing to create your own radio.

You will

1. Put together an electronic circuit containing a coil and variable capacitor that you use to tune to your favorite stations, an IC that separates the voice signal from the radio frequency carrier and an IC that amplifies the voice signal enough to power a speaker.

2. Install the circuit, speaker, on/off switch, volume control, and tuner in a handy box.