A 5/8-wave vertical is taller than a quarter-wave and concentrates its radiation at a lower takeoff angle, which is why it's a classic choice for working DX on the higher HF and VHF bands. Over good ground it shows roughly 3 dB more gain than a quarter-wave.
At 5/8 of a wavelength the element isn't resonant — it looks capacitive — so it needs a base loading coil (or a shunt-coil / L-network) to cancel the reactance and present 50 ohms. Give it the same radial field as any vertical.
| Band | Vertical radiator length | Each radial (use 4 or more) |
|---|---|---|
| 160m | 93.69 m / 307.4 ft | 37.47 m / 122.9 ft |
| 80m | 47.47 m / 155.7 ft | 18.99 m / 62.3 ft |
| 60m | 33.23 m / 109.0 ft | 13.29 m / 43.6 ft |
| 40m | 25.07 m / 82.3 ft | 10.03 m / 32.9 ft |
| 30m | 17.58 m / 57.7 ft | 7.03 m / 23.1 ft |
| 20m | 12.56 m / 41.2 ft | 5.02 m / 16.5 ft |
| 17m | 9.82 m / 32.2 ft | 3.93 m / 12.9 ft |
| 15m | 8.39 m / 27.5 ft | 3.35 m / 11.0 ft |
| 12m | 7.14 m / 23.4 ft | 2.85 m / 9.4 ft |
| 10m | 6.25 m / 20.5 ft | 2.50 m / 8.2 ft |
| 6m | 3.52 m / 11.6 ft | 1.41 m / 4.6 ft |
Model this antenna interactively → for gain, takeoff angle and azimuth/elevation patterns.
Roughly 3 dB over a quarter-wave over good ground, delivered at a lower takeoff angle. Over poor or average soil the raw gain edge shrinks but the lower angle still helps DX.
A 5/8-wavelength element is not self-resonant and presents a capacitive reactance. A base loading coil (or L-network) cancels that reactance and matches it to 50 ohms.
The radiator is about 0.625 wavelengths long, with a small velocity-factor reduction. See the per-band chart above for exact lengths.
It works, but it gets physically tall on the low bands, and once an antenna is much taller than about 0.6 wavelengths the pattern starts lifting to higher angles. It shines most on 10 m, 6 m and 2 m.