Signal Slinger™ EFHW-728A End-Fed Half-Wave 40/20/15/10m Antenna

Signal Slinger™ EFHW-728A

End-Fed Half-Wave

40/20/15/10m Antenna

These antennas are small, high-performance End-Fed Half Wave multi-band HF antennas. Very easy and quick to deploy. They are also very rugged.

  • No antenna tuner is needed on specified transmit bands. Typical SWR <1.5:1.
  • Needs no counterpoise and in most cases no ground is required.
  • Much more discrete (stealth) compared to center-fed antennas.
  • Small and lightweight enough for QRP/Portable i.e. Hiking, Camping, POTA use but also suitable for use in permanent installations.
  • Ideal for HOA compliance and/or stealth applications.
  • Model EFHW-728A-100 Can handle up to 100-125w transmit power ICAS.

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Our EFHW antennas are built to last for many years. Built with pride using high-quality stainless steel hardware and best-quality components along with high-quality insulated antenna wire.

Each antenna built by DBK Products is quality checked and then tested using a spectrum analyzer, tracking generator, and return loss bridge followed by actual on-air tests with a ham transceiver before shipping. Each antenna comes complete with matching transformer, antenna wire, and 6-page printed user manual. Ready to go right away!

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Key Benefits of EFHW Antennas

  • Single‑point support: You only need one tree, mast, or structure to get on the air. Perfect for portable ops or tight backyards.
  • Multi‑band capability: A properly designed EFHW resonates not only on its fundamental frequency but also on its harmonics, giving you multiple bands with no tuner. See typical SWR plot below.
  • Low visual impact: A thin wire and a small transformer blend easily into almost any environment — ideal for stealth installations.
  • High efficiency: With minimal feedline loss and a resonant radiator, EFHWs deliver strong performance even at QRP levels.
  • Flexible deployment: Slopers, inverted‑Ls, horizontal runs, or even zig‑zags — EFHWs tolerate creative layouts without falling apart electrically.
  • Portable‑friendly: Lightweight, compact, and fast to deploy, they’re a favorite for SOTA, POTA, and field work.

 

Some information about End-Fed Half Wave (EFHW) antennas

As the name indicates, the EFHW antenna is one half of a wavelength long on the lowest desired band of operation.

The EFHW antenna uses a broad-band matching transformer which transforms the high impedance (usually 2000-5000Ω) of the end-fed antenna wire down to the 50Ω impedance which is needed for most modern transmitters & receivers.

Tuning range of the EFHW antenna is determined by wire length of the radiator. Wire length is usually chosen to be approx. 1/2 wavelength at the lowest desired operating frequency. For example, a 40-10m EFHW antenna will use a wire length of approx. 65ft(20m). The antenna will then be naturally resonant on the chosen band and will also be resonant on odd & even harmonics of the fundamental frequency or chosen band, allowing for multi band operation without the need for an antenna tuner.

It is very efficient and is able to provide resonant operation on multiple bands both transmit & receive while using a minimum of space. This makes it attractive to those who live in HOA restricted areas such as apartments and condos, and others who want or need low visual impact.

The EFHW antenna is also a very good option for portable and temporary field use because it is very easy to deploy and remove, requires very little or no ground system, and does not require the use of an antenna tuner on resonant bands.

The End Fed Half Wave (EFHW) antenna is a very good option for many radio users – Amateur Radio, SWL, EMCOMM, etc.

 

 

 

Mounting & Deployment Options

 

The Signal Slinger matching transformer has been carefully designed to support deployment in a variety of ways. See the following illustrations for general ideas.

  • Directly supported by the antenna as an integral part, shown here:

 

  •  Mounted to a wall or other non-metallic support structure as shown below. Orient transformer so as to place eye bolt openings in parallel with and closest to mounting surface. Use screws or bolts etc. inserted through eye bolt openings to securely mount transformer. Do not tighten screws/bolts any more than necessary for a secure mount. Over tightening may damage the transformer housing.