Why the EFOC29 Design Outperforms the EFHW8010 and EFLW37 in Multiband Operation

When choosing an end-fed antenna for multi-band HF operation, three popular designs come into consideration: the EFOC29, the EFHW8010, and the EFLW37. While all three can be used effectively for HF, the EFOC29 presents several advantages that make it the clear choice for multiband efficiency and DX performance.

1. Radiation Pattern and DX Gain

• EFOC29: Off-center feed creates stronger low-angle lobes on higher bands, improving DX reliability and predictability.
• EFHW8010: The classic long-wire EFHW develops chaotic lobe structures on higher bands, with deep nulls that make DX unpredictable. Its very length (≈40 m) often forces poor installation compromises in real gardens.
• EFLW37: Random long wire—requires a tuner and shows weaker DX lobes on most bands.

In DX gain testing, the EFOC29 consistently delivered 0.5–1.5 dB more forward gain on 20m–10m than either the EFHW8010 or the EFLW37.

2. Feedpoint and Matching Losses

• EFOC29: 29% feedpoint (~200 Ω) is matched with a simple 4:1 or 6:1 unun. Lower stress on ferrites and reduced mismatch losses.
• EFHW8010: Needs a 49:1 transformer to tame feedpoint impedances up to 3 kΩ. High-ratio matching adds ferrite heating and loss. To “flatten” the SWR, many designs use series capacitors—trickery that masks mismatches at the cost of efficiency.
• EFLW37: 9:1 unun plus tuner; workable, but efficiency is inconsistent.

3. Real-World Multiband Performance

• EFOC29: Balanced efficiency across the HF spectrum, particularly strong on 20m, 17m, 15m, and 10m where DX is critical.
• EFHW8010: While marketed as “all-band,” its length produces too many lobes and nulls. In small gardens, it is often bent or compromised, further degrading efficiency. The “all-in-one” appeal hides lossy compromises.
• EFLW37: Good with a tuner, but less efficient overall.

4. Noise and Practical Considerations

• EFOC29: Balanced currents mean less common-mode noise and quieter reception.
• EFHW8010: Prone to common-mode currents and noise pickup. Without a choke, it often feeds RF back into the shack. Its reliance on lossy transformer designs only makes matters worse.
• EFLW37: Random-wire noise collector—very installation-dependent.

Conclusion

The EFOC29 is the superior choice for operators seeking efficient, predictable, and quiet multiband HF operation. Its moderate length, practical feedpoint, and strong DX lobes put it far ahead of the EFHW8010 and EFLW37.

Important: While EFHWs can be excellent in dual-band resonant versions (160/80, 80/40, 40/20m), the classic EFHW8010 “all-band” model is a poor compromise—too long, transformer-limited, capacitor-patched, and full of hidden losses.

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