Why a 1/4, 1/2 and 5/8 Ground Mounted Vertical perform the Same?

Many antenna designs promise better performance by being longer: a 5/8-wave is often said to outperform a 1/4-wave vertical, and a half-wave dipole is considered more efficient than shorter configurations. But here's the catch: when mounted very close to ground level, these differences nearly vanish. Here's why.

Current Distribution is What Matters

An antenna radiates based on where and how strongly current flows along its length. The parts of the antenna carrying the most current contribute most to radiation. For vertical antennas, this current typically peaks somewhere along the radiator depending on its length and impedance behavior:

  • 1/4 wave: Current peaks at the base
  • 1/2 wave: Current peaks at the center (vertical dipole) 
  • 5/8 wave: Current peaks somewhere above the base

But if the base of the antenna is mounted right above the ground, all these current peaks sit just a few meters off the ground—often too low to escape ground absorption.

Ground Loss Dominates When Close to Earth

When an antenna is mounted at or near ground level, the energy it radiates has to pass through the near-field zone directly above lossy Earth. This leads to heavy attenuation due to poor conductivity and dielectric loss in soil. The farther the current peak is from the ground, the better the antenna performs.

However, a ground-mounted 5/8-wave vertical—even with its current peak somewhat higher—is still not high enough to significantly reduce ground losses compared to a shorter 1/4-wave.

Likewise, a half-wave dipole with its center just a couple of meters above ground sees both halves of the dipole radiating into the lossy environment, squandering any theoretical efficiency benefit.

Radiation Pattern Is Also Flattened Equally

All three antenna types produce mostly high-angle radiation when close to the ground. That means more NVIS (Near Vertical Incidence Skywave) and less DX. The low take-off angle advantages often cited for longer antennas only show up when mounted high enough that their current maxima and physical extent are above the lossy zone.

Conclusion: Height Beats Length

In practical terms:

  • A 5/8-wave is not automatically better than a 1/4-wave.
  • A dipole isn't "more efficient" if it's still buried in ground clutter.
  • All three are equally crippled by poor height.

If you want real performance gains, focus on getting more of the current above ground level, not just making the antenna longer. In a low-mounted setup, they all perform more or less the same.

Raise the current, not the hype.

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Written by Joeri Van Dooren, ON6URE – RF, electronics and software engineer, complex platform and antenna designer. Founder of RF.Guru. An expert in active and passive antennas, high-power RF transformers, and custom RF solutions, he has also engineered telecom and broadcast hardware, including set-top boxes, transcoders, and E1/T1 switchboards. His expertise spans high-power RF, embedded systems, digital signal processing, and complex software platforms, driving innovation in both amateur and professional communications industries.