TermiLoop 160–6 vs EFHW & BBTD — Which is the Better All-Band Option?
Many operators want “one antenna for all bands” without the constant hassle of switching wires or adjusting tuners. The TermiLoop 160–6, the common 7-band EFHW with a “compensation” capacitor, and the classic Broadband Terminated Dipole (BBTD) all aim to fill that role — but their efficiency and real-world behavior differ dramatically.
Why Efficiency Matters More Than SWR
On paper, all three designs can show a pleasingly flat SWR curve. But a low SWR is no guarantee of efficiency — it only means the transmitter sees a reasonable impedance. How the antenna gets there makes all the difference. In some cases, “wideband” performance is bought at the cost of burning power in resistors or heating ferrite cores.
TermiLoop 160–6 — Smarter Termination, Better Balance
The TermiLoop uses 27 m of folded wire (effective 29 m electrical length), fed with a 4:1 UNUN and terminated with a 500 Ω resistor placed just 55 cm before the cold side. This preserves far more radiating current than the center-terminated BBTD, especially on the low bands. The result is a broadband match with less power lost to the resistor, stable radiation patterns, and a noise-quieter receive profile.
7-Band EFHW with “Compensation” Capacitor — Masking Transformer Loss
Most 80–10 m EFHWs marketed as “wideband” use a 49:1 transformer wound on ferrite that is outside its optimum frequency range at both ends. At low frequencies, core permeability limits matching efficiency; at high frequencies, winding capacitance and leakage inductance kill performance. The parallel “compensation” capacitor simply flattens the SWR by creating a resonant path — but it does not improve RF transfer efficiency. In practice, these designs often drop below 50 % efficiency on the low bands and heat noticeably under high power.
Classic BBTD — The Convenience–Loss Tradeoff
The BBTD, also known as the TTFD, is a balanced broadband dipole with a termination resistor placed at the current minimum (center). It offers exceptional SWR stability and truly wide coverage without ferrite core losses — but the cost is steep: much of the RF power is dissipated as heat in the resistor, especially on 160 and 80 m. For NVIS, it’s a convenient but lossy solution.
Real-World Efficiency Comparison
| Antenna Type | Low-Band Efficiency (160/80 m) |
Mid-Band Efficiency (40/30/20 m) |
High-Band Efficiency (17–10 m) |
Coverage |
|---|---|---|---|---|
| TermiLoop 160–6 | 55–65 % | 65–75 % | 60–70 % | 160–6 m <3:1 SWR |
| 7-Band EFHW w/ Cap | 40–50 % | 55–65 % | 45–55 % | 80–10 m “flat” SWR but efficiency drops at band edges |
| Classic BBTD | 20–40 % | 40–60 % | 50–65 % | 160–10 m wide SWR but very high termination loss |
Key Takeaways
- The TermiLoop still loses some power to its termination resistor — but far less than a BBTD, and without ferrite overheating issues common to EFHWs.
- The 7-band EFHW’s “compensation” capacitor hides SWR variation but can’t hide real-world losses, especially on 160/80 m and 10 m.
- The BBTD is maintenance-free and tuner-free, but sacrifices a large portion of transmitted power for that convenience.
- For operators who want one antenna that performs acceptably across 160–6 m with less compromise, the TermiLoop is a strong candidate.
Mini-FAQ
- Does the TermiLoop need a tuner? — No, it presents <3:1 SWR across 160–6 m when installed correctly.
- Can I run QRO? — Yes, the QRO version handles 1.5 kW SSB and 600 W digital/CW.
- Is the EFHW more compact? — Slightly, but the performance loss on the low bands is significant compared to the TermiLoop.
- Is the BBTD quieter on RX? — Not necessarily — termination dampens resonances, but the TermiLoop achieves similar quieting with less loss.
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