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Which antennas are used at HF?

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The HF band spans 3–30 MHz (wavelengths 100–10 m) under the ITU band nomenclature, and supports long-distance skywave propagation via the ionosphere.[1][2] Common HF antennas are horizontal dipoles and inverted-Vs, verticals with radials, end-fed wires, loops, and rotatable Yagis and log-periodics; their size and height above ground dominate performance.[3]

How does height affect an HF dipole?

A horizontal dipole and its ground image form a two-element array. At a height of λ/2 the main elevation lobe is near 30°; at 1λ near 15°. Low dipoles (below about λ/4) radiate mostly upward, ideal for near-vertical-incidence skywave (NVIS) coverage out to a few hundred kilometers, while long-distance (DX) paths favor low elevation angles from higher antennas.[3][2]

A vertical radiates at low angles from a single support, but over real ground its efficiency depends on the radial system, and ground losses in the near field can be large. Elevated radials or many buried radials, and siting over saltwater, improve performance markedly.[3]

Is efficiency critical for HF receiving?

Less than for transmitting. Atmospheric and man-made noise at HF is far above receiver noise, so an inefficient receiving antenna (small loop, Beverage) can achieve the same signal-to-noise ratio as a full-size one as long as external noise still dominates its output.[4]

Frequently asked questions

How long is a 40 m dipole?

About 20 m for 7.1 MHz using L ≈ 142.6/f(MHz).

What is NVIS?

Near-vertical-incidence skywave: high-angle radiation reflected by the ionosphere for regional coverage.

Do HF antennas need tuners?

Multiband wires usually do; resonant single-band antennas often do not.

References

Online sources accessed October 21, 2026; printed works cited by edition. See all sources.

  1. “Recommendation ITU-R V.431: Nomenclature of the frequency and wavelength bands used in telecommunications”. ITU-R. current edition.
  2. “Recommendation ITU-R P.533: Method for the prediction of the performance of HF circuits”. ITU-R. current edition.
  3. “The ARRL Antenna Book for Radio Communications”. ARRL. multiple editions.
  4. “Recommendation ITU-R P.372: Radio noise”. ITU-R. current edition.
Categories: Applications by band