TermiLoop 160–6 vs EFHW & BBTD — Which is the Better All-Band Option?

What the SWR Curve Does Not Tell You

Many operators want one antenna that covers many bands without constant wire changes, relay boxes, or tuner gymnastics. The TermiLoop 160–6 technical overview, the common multi-band EFHW with a “compensation” capacitor, and the classic Broadband Terminated Dipole, often called a BBTD or TTFD, all try to solve that problem.

They do it in very different ways. More importantly, their real-world performance cannot be judged from SWR alone.

Why Efficiency Matters More Than SWR

On paper, all three antenna types can show a pleasing SWR curve. But low SWR does not prove high radiation efficiency. It only tells you that the transmitter sees a load it can work into.

A broadband match can come from useful radiation, intentional resistive damping, transformer loss, ferrite heating, feedline loss, ground loss, common-mode current, or several of these mechanisms at the same time. A dummy load has excellent SWR too. That does not make it an antenna.

TermiLoop 160–6: Broadband Matching with Controlled Termination

The TermiLoop uses 27 m of folded wire, with an effective electrical length of about 29 m, fed through a 4:1 UNUN and terminated with a 500 Ω resistor placed close to the cold side. The goal is not to create a magic lossless antenna. The goal is to obtain a wide operating range while keeping as much current as practical in the radiating structure instead of deliberately dumping a large part of the power into a termination resistor.

On 160 m, this kind of antenna is still electrically small. That matters. The result depends heavily on installation height, ground environment, conductor resistance, nearby objects, termination current, feedline routing, and common-mode control. In a favorable installation, the TermiLoop can be a practical broadband compromise. But it should not be described with universal fixed efficiency numbers unless those numbers are backed by clearly stated modeling or measurement conditions.

Multi-Band EFHW with Compensation Capacitor: A Better Match Is Not Always Better Radiation

Many 80–10 m EFHW antennas use a high-ratio transformer, often around 49:1, together with a small capacitor to improve the SWR curve on the upper bands. This can be a useful and convenient arrangement. Many operators use EFHW antennas successfully, especially when the wire length, feedline, counterpoise behavior, and choking are handled properly.

But the compensation capacitor should not be misunderstood as an efficiency improvement by itself. It can help shape the impedance seen by the transmitter, but it does not remove transformer loss, winding capacitance, leakage inductance, ferrite heating, common-mode effects, or high-band pattern breakup.

In other words, the capacitor can make the antenna look friendlier to the radio. It does not automatically prove that more accepted power is becoming useful radiation.

Classic BBTD / TTFD: Convenient, Stable, and Intentionally Lossy

The Broadband Terminated Dipole, often called a TTFD, is a balanced broadband antenna that uses a termination resistor to damp resonances and stabilize impedance over a wide frequency range. This can be very attractive where frequency agility matters more than maximum efficiency.

The tradeoff is built into the concept: some of the applied RF power is intentionally dissipated in the termination resistor. How much depends on frequency, geometry, height, resistor value, soil, surroundings, and feed arrangement. On the lower bands, where the antenna may be electrically short, that loss can become significant.

For receive, utility use, military-style broadband coverage, emergency listening, or convenience-first operation, that may be an acceptable tradeoff. For maximum transmitted field strength, it is a compromise.

Practical Comparison

The table below is qualitative. It is not a calibrated efficiency measurement. Exact numbers require model files, resistor dissipation estimates, transformer loss data, height, soil assumptions, feedline details, and measurement method.

What This Means in Practice

The TermiLoop is best understood as a broadband compromise, not as a lossless replacement for a full-size resonant antenna. Its advantage is that the termination is used in a more controlled way than in a classic BBTD/TTFD, while avoiding some of the transformer stress and ferrite-loss concerns that can appear in compact multi-band EFHW systems.

The EFHW remains attractive when simplicity, compactness, and quick deployment matter. But its efficiency cannot be inferred from SWR alone, especially across many bands. The transformer, feedline, counterpoise behavior, common-mode current, and installation geometry all matter.

The BBTD/TTFD remains attractive when predictable broadband matching matters more than absolute transmitted field strength. That is not a failure. It is simply the design tradeoff.

Key Takeaways

• A low SWR curve does not prove that most of the RF power is being radiated.
• The TermiLoop uses termination as part of a broadband strategy, but it still has installation-dependent loss.
• On 160 m, any 27–29 m wire-based antenna must be discussed carefully because it is electrically small.
• An EFHW compensation capacitor can improve the match, but it does not automatically improve radiation efficiency.
• A classic BBTD/TTFD is broadband because it uses intentional damping, and that damping can consume real RF power.
• For serious efficiency comparisons, the assumptions must be stated: model, height, soil, termination power, transformer loss, feedline behavior, and measurement method.

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