What changed
Yagis, beams and directional antennas — edited Aug 31, 2026 by Unknown editor
This is the first recorded version, so every line is shown as added. Note: Imported from content/wiki
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A Yagi puts a driven element between a reflector and one or more directors, concentrating radiation
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in one direction. You gain signal both ways — you transmit stronger and hear less noise from
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everywhere else.
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## What gain buys
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A three-element Yagi gives roughly 6–7 dBd forward gain — about an S-unit — plus 15–25 dB of
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front-to-back rejection. That rejection is often more valuable than the gain, because it removes
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interference and noise from behind you.
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## What it costs
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- A rotator, a mast or tower, and a structural engineering problem
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- Wind loading, ice loading and a permit conversation with the neighbors
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- Money: a small HF beam plus rotator plus tower is a four-figure project
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## On VHF/UHF it is cheap
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A 2 m or 70 cm Yagi is small enough to build from tape measures and PVC for under $20. Handheld
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Yagis are how people work [satellites](/wiki/operating/satellites) and run direction-finding
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("fox hunt") events.
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## Other directional antennas
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- **Moxon** — compact two-element, excellent front-to-back, easy to build.
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- **Quad** — loops rather than dipoles; slightly more gain per boom foot, more wind area.
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- **Hex beam** — multiband, light, popular where a full-size Yagi will not fit.
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- **Log periodic** — wide bandwidth, less gain, no retuning across bands.
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## Antenna restrictions
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Deed restrictions and HOAs are the usual obstacle. Attic antennas, flagpole verticals, wires in
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trees and portable operating are the standard responses. Some states have laws requiring HOAs to
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reasonably accommodate amateur antennas; check yours.