Level 2 · Lesson 2.3

Antenna basics

Jimmy Bob, a friendly cartoon mountain man in a trucker cap and overalls

“A cheap radio on a good antenna beats a fancy radio on a bad one every day of the week.”

You'll be able to

describe dipole, vertical, and Yagi antennas, and explain SWR and coax.

A half-wave is two equal wires fed in the middle, with a total length in feet of about 468 divided by frequency in MHz. A quarter-wave uses ground or as its other half. A beam has several elements and focuses energy in one direction, which is called . Coaxial cable carries the signal to the antenna, and measures how well they are matched; 1:1 is perfect and below 2:1 is generally fine.

Tap an underlined word for its meaning.

Try it

On-air activity

cut a virtual dipole for 146 MHz and 14.2 MHz and watch the SWR meter.

This one happens on the air in The Shack, which opens in a later phase.

Quick check

Get 2 of 3 right to complete the lesson.

1. About how long is a half-wave dipole for 14.2 MHz?
2. An SWR of 1:1 means…
3. A Yagi antenna…

Antenna basics

You'll be able to

Try it

Quick check

Words from this lesson