EFOC8 Antenna Installation Guide

Thank you for your order! You have received 9 meters of high-quality antenna wire, 14 meters of coaxial cable (EXTRAFLEX-BURY-7), and a big ferrite choke, 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: ±7-8 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 5-8M

2. Sloper Configuration

  • Recommended Length: ±7-8 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 5-8M
  • The end of the sloper needs to be 3-4M above ground !

3. Choke Placement

The first  2.2 meters of coax braid acts as the counterpoise for the antenna. This section can be laid horizontally, or placed flat on the ground, but for optimal performance, slight elevation above ground is recommended to minimize losses. At 2.2 meters, you need to install the included choke (6 turns around the coax) to isolate the counterpoise from the rest of the feedline. 

4. 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

5. 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

6. Tuning

Start by adjusting for the 20M band, aiming for the SWR dip to appear at the beginning of the band, ideally around 1.1:1. On 10M, the dip should be near the center of the band, around 1.4:1 SWR.

For 17M, 15M, and 12M, the SWR dip should follow a natural progression, typically around 2:1 SWR. On 6M, expect an SWR of approximately 1.5:1.

Keep in mind that antenna height has a major impact on SWR behavior. For a more consistent SWR across all bands, it is recommended to mount 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!