Section 1.1: Electrical Basics #

Let’s start with the most basic question: what does electricity flow through, what does it not, and why?

Conductors and Insulators #

Materials fall into two main categories when it comes to electricity: conductors and insulators.

Key Information:

• Metals are good conductors because they have many free electrons.
• Glass (along with plastic and rubber) is a good electrical insulator.

Conductors are materials that allow electrical charges to flow through them easily. Most metals are good conductors because they have many free electrons — charges that can move around freely when a voltage is applied. This is why we use metals like copper in antennas, power cables, and the wiring inside our radios: those free electrons make it easy for electrical current to flow. A fun fact: silver is actually a better conductor than copper, but its high price makes it impractical for most applications!

Insulators, on the other hand, are materials that resist the flow of electricity. They act like barriers, keeping electricity where we want it and preventing it from going where we don’t want it. Glass, plastic, and rubber are all good insulators.

You can find examples of conductors and insulators working together all around you. Look at any electrical cord in your house — the copper wires inside are conductors, carrying electricity to your appliances, while the plastic coating around the wires is an insulator, keeping that electricity safely contained. In amateur radio, we use both conductors and insulators together in similar ways to build safe and effective stations.

Knowing what carries electricity and what blocks it is a good start — but to actually work with it, we need to be able to measure it. That’s where things like voltage, current, and resistance come in.