End Fed Half Wave Antennas: Mounting advice

When installing a wire antenna, avoid over tightening the wire. It’s best to leave a slight bend or sag in the wire. This helps prevent excessive tension, which can damage the wire, insulators, or support structures, and allows for flexibility during temperature changes or wind. A little slack ensures better longevity and performance of the antenna.

For longer wire antennas, it can be beneficial to use a pulley system with a counterweight. This setup allows the wire to adjust naturally to changes in tension caused by wind, temperature variations, or movement in the support structures. The counterweight helps maintain consistent tension without overstressing the wire or its attachment points, reducing the risk of damage and ensuring better long-term stability and performance of the antenna.

EFHW8010 and EFHW4010 as a Sloper

For DX on Higher Bands (e.g., 20m, 17m, 15m, 10m):

  • Use a slope angle of 30–45° to favor low-angle radiation.
  • Place the feedpoint as high as possible (10m or more) to improve performance.

For Regional NVIS Communication (e.g., 40m, 80m):

  • Use a steeper slope, around 60–75°, to direct energy upward.
  • Lower the feedpoint height slightly (~5m) to enhance high-angle radiation.

For a Multi-Band, All-Purpose Setup:

  • Use a 45° slope for balanced performance across bands.
  • A feedpoint height of 7–10m works well for both DX and NVIS.

Grounding:

  • We recommend grounding to protect the equipment from static surges; however, it is optional for the operation of the antenna!

Directivity

  • The dominant power typically radiates in the direction of the slope, downward and outward from the high feed point toward the lower endpoint. However, some energy also radiates upward and in the opposite direction, but it’s usually weaker. If your goal is to optimize directional radiation (e.g., for DXing), aligning the slope toward the intended coverage area is key.

Alternatives: * with feed point at least 5m above ground !

Inverted V:

    • Best for balanced NVIS and DX performance, especially on lower bands.
    • Requires less vertical height but needs space for the sloping wires.
    • An inverted V generally radiates equally in both directions perpendicular to the plane of the V, provided the angle between the legs and the ground symmetry are ideal. This is because the current distribution in the legs produces radiation patterns that combine and cancel symmetrically in certain directions.

    Inverted U:

      • Best for DX-focused operation, especially on higher bands where the vertical section enhances low-angle radiation.
      • Works well in limited horizontal space but requires a taller support structure for the vertical portion.
      • At higher elevations (0.3 λ - 0.5 λ), the pattern shifts toward lower angles, making it more suitable for DX communication.
      • Maximum radiation occurs perpendicular to the plane of the U, meaning the strongest radiation is in the directions broadside to the U’s “open ends.”
    Both configurations will alter the antenna’s impedance and resonance. Be prepared to use a tuner or adjust the wire length slightly.

    EFHW16080 as a Inverted L

    Inverted L ... 18M SpiderBeam pole

    • Performs adequately on 160M and delivers good performance overall on 80m. Ensure the end of the antenna is kept as high as possible, with a minimum height of 3m. The feed point should also be positioned at least 3m above the ground.
    • Both bands are excellent for NVIS operation !
    • Requires a grounding stake or ground plane for the antenna to operate effectively!

    Inverted L ... 26M SpiderBeam pole

    • Performs better on 160M and delivers good performance excellent on 80m. Ensure the end of the antenna is kept as high as possible, with a minimum height of 3m. The feed point should also be positioned at least 3m above the ground. 
    • Both bands excel in NVIS operation, with 80M also offering good DX capabilities at this height!
    • Requires a grounding stake or ground plane for the antenna to operate effectively!

    EFHW8040 as a Inverted L

    Inverted L ... 18M SpiderBeam pole

    • Performs excellent on 40M and delivers good performance overall on 80m. Ensure the end of the antenna is kept as high as possible, with a minimum height of 3m. The feed point should also be positioned at least 3m above the ground.
    • 80M offers both good DX and NVIS, with 40M offering excellent DX capabilities at this height, NVIS on 40M will be moderate !
    • Requires a grounding stake or ground plane for the antenna to operate effectively!

    Inverted L ... 26M SpiderBeam pole

    • Ensure the end of the antenna is kept as high as possible, with a minimum height of 3m. The feed point should also be positioned at least 3m above the ground. 
    • Both bands excel in DX operation, with 80M also offering good NVIS capabilities !
    • Requires a grounding stake or ground plane for the antenna to operate effectively!

    EFHW Antenna Minimum Ground Clearance 

    These are the minimum recommended clearances! When used as a flat-top configuration, performance will be significantly compromised. These values serve as a guideline for the lowest part of the antenna when installed in configurations such as an Inverted L, Inverted V, Sloper, or Inverted U, where the majority of the wire is positioned well above these minimum heights and the endpoints of the wire can be at these minimum clearances.

    Band (Meters) Frequency (MHz) Wavelength (λ) Effective Ground
    (1/10 λ)    		 Normal Ground
    (1/20 λ)
    160m 1.8 166.67m 16.67m 8.33m
    80m 3.5 85.71m 8.57m 4.29m
    60m 5.3 56.60m 5.66m 2.83m
    40m 7.1 42.25m 4.23m 2.12m
    30m 10.1 29.70m 2.97m 1.49m
    20m 14.2 21.13m 2.11m 1.06m
    17m 18.1 16.57m 1.66m 0.83m
    15m 21.2 14.15m 1.42m 0.71m
    12m 24.9 12.05m 1.20m 0.60m
    10m 28.5 10.53m 1.05m 0.53m

     

    Multiple antennas on the same supporting mast ?

    Condition Recommended Angle Reason
    Minimum Angle ≥ 90° Minimizes coupling and interaction for most setups, providing acceptable isolation.
    Optimal Angle for Isolation 180° Maximizes isolation and minimizes mutual coupling, ensuring independent operation.
    Multiband Setup ≥ 120° Reduces interaction across bands, prevents pattern distortion, and ensures good coverage.
    Compact Space 45° Can work for directional antennas or high frequencies but leads to significant coupling.
    Resonant Wire Antennas (e.g., EFOC, EFHW, Dipoles) ≥ 120° Reduces mutual coupling due to their broad radiation patterns and potential interaction.
    Directional Antennas (e.g., Yagis) ≥ 90° Tolerant of closer spacing because of narrower radiation patterns.
    Cross-Polarized Antennas ≤ 90° Can be closer together as interaction is minimal due to polarization differences.