Designing a Yagi with AA2KH Antenna Designer — Step-by-Step Walkthrough

AA2KH Antenna Designer — Complete Guide to Features & Setup

Overview

AA2KH Antenna Designer is a lightweight Windows freeware tool (latest known version 2.15, c. 2010) by Philip T. Morrissey (call AA2KH) for designing common wire and Yagi-type amateur-radio antennas. It focuses on simple, practical calculations: element lengths, spacing, feedpoint locations, and basic construction details.

Key features

• Antenna types: dipoles, folded dipoles, quads, delta loops, Yagis/beam elements, and basic wire antennas.
• Frequency input: design by target operating frequency (single-band).
• Automatic element calculations: computes wire lengths, spacing, and element diameters.
• Practical build details: suggests pole sizes, drilling locations, and where to attach feed/wires.
• Small footprint: very lightweight, portable Windows executable (zip ~54 KB).
• Freeware: no-cost distribution historically available from freeware archives.

System requirements

• Windows (most legacy versions run on Windows XP through Windows 10; may require compatibility mode on newer Windows).
• Minimal disk space and RAM.

Download & safety

• Available from freeware archives (e.g., Softpedia) and ham-radio bulletin boards.
• Verify download source and scan with up-to-date antivirus before running, since many archives host old executables.

Quick setup & first run

1. Download and extract aa2kh.zip to a dedicated folder.
2. Right-click the executable → Properties → Compatibility (if needed) → run in an older Windows mode.
3. Run the exe; no installer typically required.

Basic workflow (example: designing a 20‑m dipole)

1. Choose antenna type: Dipole.
2. Enter frequency: 14.200 MHz.
3. Select wire diameter (or leave default).
4. Read computed total length and each leg length; note suggested feedpoint/drill locations.
5. Transfer dimensions to your build plan; allow for trimming during on‑site tuning with an antenna analyzer or SWR meter.

Practical tips

• Treat computed lengths as starting points — real-world tuning (SWR/analyzer) is essential.
• Use an antenna analyzer or SWR meter and add small adjustable end‑loading or tuning coils if required.
• For Yagis, check mechanical strength for wind loading; follow suggested pole sizes.
• If running on Win11/64-bit, use compatibility mode or run in a VM if the program fails.

Limitations

• Single‑frequency/simple models only — not a full EM solver (no NEC-style propagation/radiation pattern plots).
• Interface and documentation are dated; expect basic UI and minimal help files.
• May not fully support modern multi-band designs or optimization features.

Alternatives (if you need advanced modeling)

• EZNEC / NEC‑based tools (NEC2/4 frontends) for rigorous modeling and patterns.
• MMANA-GAL for freeware NEC modeling and pattern plots.
• 4NEC2 for more advanced NEC simulations.

Where to learn more

• Archived ham‑radio forums, club newsletters, and Softpedia page for downloads and screenshots.
• Use club Elmer resources or local amateur radio groups for practical build and tuning guidance.