EFOC29 Antenna Installation Guide

Thank you for your order! You have received 30 meters of high-quality antenna wire, 24 meters of coaxial cable (EXTRAFLEX-BURY-7), and two big ferrite chokes, which can be used for various configurations. Below are approximate wire lengths required for different antenna setups.

1. Flat-Top (Horizontal) Configuration

  • Recommended Antenna Wire Length: ±28-30 meters
  • A classic setup where the wire is fully extended in a straight line, ideal for low-angle radiation and general HF coverage.
  • Recommended Feed Point height is 7-10M

2. Inverted-L Configuration

  • Recommended Length: ±26-28 meters (Horizontal: 15-20m, Vertical: 7-12m)
  • The wire runs vertically for a section and then horizontally, often supported by a mast and a tree or pole.
  • Good for both NVIS and DX operation, depending on height.
  • Recommended Feed Point height is 7-10M
  • The lowest section (bottom of the vertical part) needs to be 3-5M above ground

3. Inverted-U Configuration

  • Recommended Length: ±25-28 meters (Vertical sections: 6-10m, Horizontal top: 10-16m)
  • The wire is supported at two high points with a sagging section in between.
  • Useful where space is limited, balancing horizontal and vertical radiation.
  • Recommended Feed Point height is 5-7M

4. Sloper Configuration

  • Recommended Length: ±27-29 meters
  • One end is elevated, and the other slopes downward toward a lower anchor point.
  • Provides directional properties and lower noise in some setups.
  • Recommended Feed Point height is 7-10M
  • The end of the sloper needs to be 4-5M above ground !

5. Coax & Choke Placement

The first 12.2 meters of coax braid acts as the counterpoise for the antenna. This section can be zig-zagged, laid horizontally, or placed flat on the ground, but for optimal performance, slight elevation above ground is recommended to minimize losses, keep the coax at least 10–20 cm away from the metal surfaces like a metal roof. At 12.2 meters, you need to install the first included choke (6 turns around the coax) to isolate the counterpoise from the rest of the feedline. If there is no choke at your shack entrance, you can use the second choke there instead; otherwise, place it straight after the first one. This setup helps prevent common-mode currents and ensures proper RF performance.

6. Optimizing SWR Measurements

To achieve the best performance from your End-Fed Antenna, follow these key SWR optimization practices:

  • Measure SWR Away from Nearby Objects: Keep your SWR meter and feedline away from large metal objects and structures that can distort readings.
  • Check Multiple Frequencies: Take SWR measurements across different bands to ensure a broad resonance range.
  • Avoid Coax Interference: Ensure your coaxial cable is properly routed and decoupled to prevent unwanted common mode currents from affecting SWR readings.

For more details on Optimizing SWR Measurements for End-Fed Antennas, visit: https://shop.rf.guru/pages/optimizing-swr-measurements-for-end-fed-antennas

7. Folding Back vs. Cutting Wire for Tuning

If your antenna needs tuning, consider folding back the excess wire instead of cutting it. This allows for easy adjustments without permanently altering the wire length. Folding back also helps maintain structural integrity and enables future modifications. If cutting is necessary, do so gradually and test the resonance after each adjustment.

For more details on folding back vs. cutting wire antennas, visit: https://shop.rf.guru/pages/folding-back-vs-cutting-wire-antennas-essential-tips-for-optimal-performance

8. Tuning

Start by adjusting for 80M, aiming for resonance around 3.6 MHz with an SWR of 1.3:1.

On 40M, the resonant point should be just beyond the band, also with an SWR of 1.3:1.

For 20M and 10M, the resonance should occur at the beginning of each band, with an SWR of 1.5:1 on 20M and 1.1:1 on 10M.

All other bands should follow naturally, maintaining an SWR below 2.5:1, except for 30M, which should remain below 3:1 and may require a tuner.

Antenna height significantly impacts SWR behavior. For the most stable performance across all bands, install the antenna at least 8 meters high.

These measurements were taken using 30 meters of coaxial cable.

Installation Tips:

  • Insulation & Tension: Always use proper insulators and avoid excessive tension to prevent breakage.
  • Height Considerations: Higher installations improve performance, but NVIS operation benefits from lower heights.
  • Tuning: Lengths may need fine-tuning depending on local conditions and resonance.

For further assistance, feel free to contact us!