End Fed Half Wave Antennas: Energy Efficiency and DX capabilities

EFHW8010

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.
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 Compromised Poor N/A
10m 1.3 λ Compromised Poor N/A


EFHW4010

Flat Top @ 10M height

  • 40m: Efficiency is slightly reduced (86%) due to moderate ground losses and transformer losses.
  • 20m–10m: Efficiency improves significantly (93–97%) 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 Weak Poor Strong
30m 0.34 λ Moderate Moderate N/A
20m 0.5 λ Strong Excellent N/A
17m 0.56 λ Strong Excellent N/A
15m 0.67 λ Very Strong Excellent N/A
12m 0.8 λ Very Strong Excellent N/A
10m 1.0 λ Outstanding Outstanding N/A

 

EFHW16080

Inverted L ... 18M SpiderBeam pole

  • 160m: Efficiency is slightly reduced (56%) due to ground losses and transformer losses.
  • 80m: Efficiency improves significantly (93–97%) due to reduced ground losses and higher radiation resistance.

 

Band Height Relative to λ Low-Angle Radiation (<15°) DX Suitability NVIS Capabilities
160m 0.093 λ (Vertical Portion) Weak Poor Strong
80m 0.187 λ (Vertical Portion) Moderate Moderate Excellent

 

Inverted L ... 26M SpiderBeam pole

  • 160m: Efficiency is moderate (65%) due to ground losses and transformer losses.
  • 80m: Extremely high efficiency (~99.88%) because of high radiation resistance and low ground losses. 
Band Height Relative to λ Low-Angle Radiation (<15°) DX Suitability NVIS Capabilities
160m 0.16 λ (Vertical Portion) Moderate Moderate Good
80m 0.33 λ (Vertical Portion) Strong Good Moderate

 

EFHW8040

Inverted L ... 18M SpiderBeam pole

  • 80m: Efficiency is moderate (78%) due to higher ground losses and transformer losses.
  • 40m: Efficiency improves significantly (88–96%) due to reduced ground losses and higher radiation resistance.
Band Height Relative to λ Low-Angle Radiation (<15°) DX Suitability NVIS Capabilities
80m 0.187 λ (Vertical Portion) Moderate Moderate Strong
40m 0.375 λ (Vertical Portion) Strong Good Moderate

 

Inverted L ... 26M SpiderBeam pole

  • 80m: Good efficiency (89%) with reasonable radiation resistance. 
  • 40m: Very high efficiency (~94%) due to excellent radiation resistance and minimal ground losses.
    Band Height Relative to λ Low-Angle Radiation (<15°) DX Suitability NVIS Capabilities
    80m 0.33 λ (Vertical Portion) Strong Good Moderate
    40m 0.66 λ (Vertical Portion) Very Strong Excellent Weak