Why the End-Fed Half-Square Is a Game Changer for DX

The half-square antenna has long been favored by HF DXers for its low-angle radiation and directional pattern. Traditionally, it’s fed either at a corner or at the center of the horizontal wire, typically requiring a balanced feed system. But there’s a better way: the end-fed half-square. This configuration simplifies setup, enhances practical deployment, and in many cases, even improves performance by reducing common-mode issues and feedline interaction.

What Is an End-Fed Half-Square?

An end-fed half-square still consists of two quarter-wave verticals joined by a half-wave horizontal wire, but instead of feeding it in the corner with a balanced line, it uses a high-impedance matching transformer (typically 68:1 or 56:1) to feed one end of the horizontal wire directly with coax. The second vertical becomes the far leg and is simply supported at the end.

Key Benefits Over Traditional Feeding

Simplified Feedline Logistics

Traditional corner-fed half-squares require a feedpoint that is often inconveniently located mid-air or far from the shack. An end-fed version can be anchored directly from the feedpoint at the operator’s location, reducing coax length and minimizing feedline losses.

No Balanced Line or Tuner Needed

An end-fed transformer handles the impedance transformation, allowing direct feed with coaxial cable. No need for a tuner or balanced line system, making it plug-and-play.

Reduced Common-Mode Currents

Because the coax is grounded at the base and the system is electrically unbalanced by design, the setup is less sensitive to common-mode pickup if a proper choke is used. This improves receive quality and reduces unwanted coupling to the feedline.

Easier Support Requirements

With only one electrical connection at one end, setup becomes faster. You can use a pole or tree at the feedpoint and a second high support or even a slightly lower endpoint at the far side.

Portable and Field-Friendly

The end-fed half-square is ideally suited for temporary or field use. It packs easily, needs just two supports, and sets up quickly. With pre-trimmed wire and a compact transformer, it’s a DX-ready antenna for POTA, SOTA, or expeditions.

Same Performance, Less Hassle

The radiation pattern, gain, and takeoff angle remain essentially identical to a conventional half-square, as long as the dimensions and orientation are preserved. You're not sacrificing any DX performance—but gaining a lot in usability.

Use Cases

  • Fixed monoband DX antenna on 20, 30, or 40 meters
  • Quick-deploy directional antenna for contests or expeditions
  • Low-angle performance in locations where verticals are impractical

Conclusion

The end-fed half-square takes the best aspects of a proven antenna design and makes them accessible, convenient, and more practical for real-world operating. Whether for fixed or portable use, it delivers exceptional directional low-angle radiation with minimal setup hassle. For monoband DX operation, it’s hard to beat.


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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.