EFOC29

Flat Top @ 10M height

• 80m: Efficiency is moderate (78%) due to higher ground losses and transformer losses.
• Higher Bands (40m–10m): Efficiency improves significantly (88–96%) due to reduced ground losses and higher radiation resistance.
• 12m Band: The near-resonance characteristic of the EFOC antenna ensures higher radiation resistance and minimal losses, leading to excellent efficiency and a strong radiation pattern. In contrast, the 12m band on the half-wave EFHW8010 is completely compromised.
• 10m Band: Performance is slightly less effective but still usable, with better matching than a half-wave antenna of the same length.

Band	Height Relative to λ	Low-Angle Radiation (<15°)	DX Suitability	NVIS Capabilities
80m	0.125 λ	Weak	Poor*	Excellent
40m	0.25 λ	Moderate	Moderate*	Strong
30m	0.34 λ	Moderate	Moderate*	Weak
20m	0.5 λ	Strong	Excellent	N/A
17m	0.67 λ	Strong	Excellent	N/A
15m	0.89 λ	Very Strong	Excellent	N/A
12m	1.11 λ	Very Strong	Excellent	N/A
10m	1.3 λ	Moderate	Moderate	N/A

* If your goal is to improve DX performance on 80m, 40m, or 30m, raise the antenna to a height of at least 18M above the ground.

This comparison highlights that a 6m height is more NVIS-oriented for lower bands like 80m and 40m, while maintaining moderate to strong DX performance on higher bands like 20m, 17m, and 12m.

Feature	10m Height (Flat Top)	6m Height (Flat Top)
80m Band	Moderate efficiency, good NVIS	Moderate efficiency, strong NVIS
40m Band	Moderate DX, strong NVIS	Weak DX, strong NVIS
30m Band	Moderate DX	Moderate DX
20m Band	Excellent DX	Moderate DX
12m Band	High efficiency, excellent DX	High efficiency, excellent DX
10m Band	Moderate DX, usable, slightly compromised	Usable DX, slightly more compromised

EFOC17

Flat Top @ 10M height

• 40m Band: Efficiency is moderate (~85%) due to the moderate radiation resistance and ground losses. The height corresponds to 0.25λ, enabling decent DX performance and strong NVIS capabilities.
• Higher Bands (30m–10m): Efficiency improves significantly (~90–97%) due to reduced ground losses and higher radiation resistance.

 

Band	Height Relative to λ	Low-Angle Radiation (<15°)	DX Suitability	NVIS Capabilities
40m	0.25 λ	Moderate	Moderate*	Strong
30m	0.33 λ	Moderate	Moderate*	Moderate
20m	0.5 λ	Strong	Excellent	N/A
17m	0.58 λ	Strong	Excellent	N/A
15m	0.75 λ	Very Strong	Excellent	N/A
12m	0.91 λ	Very Strong	Excellent	N/A
10m	1.13 λ	Strong	Excelent	N/A

* If your goal is to improve DX performance on 40m, or 30m, raise the antenna to a height of at least 15M above the ground.

This comparison highlights that a 6m height is more NVIS-oriented for the lower band 40m, while maintaining moderate to strong DX performance on higher bands like 20m, 17m, and 12m.

Feature	10m Height (Flat Top)	6m Height (Flat Top)
40m Band	Moderate DX, strong NVIS	Weak DX, strong NVIS
30m Band	Moderate DX	Weak DX
20m Band	Excellent DX	Moderate DX
17m Band	Excellent DX	Good DX
15m Band	Excellent DX	Good DX
12m Band	High efficiency, excellent DX	High efficiency, excellent DX
10m Band	High efficiency, excellent DX	High efficiency, excellent DXd

 

EFOC8

Flat Top @ 5M height

• 20m Band: Efficiency is high due to the near-resonant length of the wire. At 5m height (0.25λ), low-angle radiation supports moderate DX performance.
• Higher Bands (17m–10m): Efficiency improves significantly due to higher radiation resistance and reduced ground losses, despite the lower height. The antenna performs very well on these bands, with excellent DX capabilities.

Band	Height Relative to λ	Low-Angle Radiation (<15°)	DX Suitability	NVIS Capabilities
20m	0.25 λ	Moderate	Moderate	Weak
17m	0.31 λ	Moderate	Good	N/A
15m	0.4 λ	Strong	Excellent	N/A
12m	0.48 λ	Strong	Excellent	N/A
10m	0.56 λ	Very Strong	Excellent	N/A

This comparison emphasizes that a 10m height (or higher) is more efficient, reinforcing the idea that height remains an important factor in antenna performance.

Feature	10m Height (Flat Top)	5m Height (Flat Top)
20m Band	Strong DX, high efficiency	Moderate DX, high efficiency
17m Band	Excellent DX	Good DX
15m Band	Excellent DX	Excellent DX
12m Band	Excellent DX, high efficiency	Excellent DX, high efficiency
10m Band	Excellent DX, high efficiency	Excellent DX, very strong radiation