The Basic lessons · Feedlines and antenna systems · B-006-011

Mastering the Multi-Band Yagi Antenna

Learn how Yagi antennas use traps to work on multiple bands and how their physical dimensions affect signal strength and direction. This lesson explains the trade-offs between gain, bandwidth, and element spacing to help you choose the right setup.

This lesson is part of SignalPrep Pro. The subsection's 11 exam questions are free to practise: practise B-006-011.

What this subsection asks

• What design feature allows a single Yagi antenna to function on the 20-metre, 15-metre and 10-metre bands?
• What is the approximate length of the driven element of a Yagi antenna for 14.0 MHz?
• What is the approximate length of the director element of a Yagi antenna for 21.1 MHz?
• What is the approximate length of the reflector element of a Yagi antenna for 28.1 MHz?
• What is one effect of increasing the boom length and adding directors to a Yagi antenna?
• What is the major advantage of increasing element spacing on a Yagi antenna?
• Why are Yagi antennas often used on HF bands from 20 metres to 10 metres?
• What does "antenna front-to-back ratio" mean in reference to a Yagi antenna?
• How can the bandwidth of a Yagi antenna be increased?
• For a three-element Yagi antenna, what approximate element spacing (in wavelengths) provides the best compromise between gain and front-to-back ratio?
• If the forward gain of a six-element Yagi is about 10 dBi, what would the gain of two of these antennas be if they were "stacked"?