Design Antenna Geometry
1 hourCalculate dipole or vertical element lengths for target frequency and environment.
Intermediate1-3 days
Antenna Building Guide
Complete guide for antenna building — step-by-step workflow, tools, checklist, and expert tips to get started.
home station buildersportable operatorsDIY enthusiasts
Workflow
Plan Impedance Match
45 minutesModel feedpoint impedance and select matching network or balun approach.
Build and Mount
3-6 hoursAssemble elements, install insulators, and raise antenna with safe clearance.
Tune and Measure SWR
1-2 hoursTrim or adjust matching until SWR meets target across operating bandwidth.
Estimate Gain & Pattern(Optional)
30 minutesCompare predicted gain and take field strength notes on first contacts.
Tools Used
- Antenna Length (Dipole / Quarter-Wave)Primary
Calculate dipole and quarter-wave element lengths for target band.
- SWR CalculatorPrimary
Verify SWR after trimming and matching adjustments.
- Antenna Length CalculatorSupporting
Cross-check element lengths for multiple band designs.
- Impedance MatchingSupporting
Design L-network or stub match for feedpoint mismatch.
- Antenna Gain CalculatorReference
Compare predicted antenna gain vs reference dipole.
Checklist
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Design
Safety
Build
Tune
Installation
Documentation
Reference Materials
Dipole Length ConstantsTable
Common approximations for wire dipoles in free space vs with ground effects.
| Design | Formula (ft) | Notes |
|---|---|---|
| Half-wave dipole | 468 / f(MHz) | Trim 2–5% for ground |
| Quarter-wave vertical | 234 / f(MHz) | Add radials for low angle |
| 5/8 vertical | 585 / f(MHz) | Needs matching coil |
468/f RuleFormula
Total dipole length in feet ≈ 468 divided by frequency in MHz — starting point before tuning.
Height MattersStandard
A half-wave dipole at λ/2 height approximates free-space pattern; lower mounts detune and skew pattern.
Build Two for Portable
Duplicate a proven dipole — field swaps are faster than on-site tuning.
Use Copper-Weld Wire
Stronger than pure copper for tree-mounted dipoles.
Never Work Near Power Lines
Antenna work is a leading cause of amateur radio fatalities — stay far from energized lines.
Safety Notes
- Do not raise masts within falling distance of overhead power lines — contact is often fatal.
- Secure antennas for wind load; falling masts and ice-loaded elements cause injury and property damage.