VE6DOK · Build Practical Antennas
DIY Builds & Antenna Length Calculator
This page turns the theory into usable build starting points. Use the formulas, cut long, measure, and adjust.
Length formulas
Dipole total length
468 / frequency MHz
Each side is half the total.
Quarter wave / radial
234 / frequency MHz
Useful for verticals, radials, and counterpoise starting points.
Common HF lengths
| Band | Frequency | Dipole total | Each side / quarter-wave |
|---|---|---|---|
| 80m | 3.6 | 130 ft | 65 ft |
| 40m | 7.1 | 66 ft | 33 ft |
| 20m | 14.2 | 33 ft | 16.5 ft |
| 15m | 21.2 | 22 ft | 11 ft |
| 10m | 28.5 | 16.4 ft | 8.2 ft |
Build paths
Beginner dipole
Cut long, install safely, measure, trim.
Portable end-fed
Use a matching unit and planned counterpoise.
Doublet
Use ladder line and a capable tuner.
Vertical
Build the radial field as seriously as the radiator.