Safe Distance for Active Antennas from the Home

Introduction

Active antennas, such as e-probes, MiniWhip-style receivers, and other broadband active receiving antennas, are widely used by radio enthusiasts and professionals due to their compact size and excellent low-frequency performance. However, their placement is crucial to ensuring optimal reception and minimizing interference from household electronic devices. A reasonable installation distance of 3 to 5 meters from the home is recommended for most setups.

Why Distance Matters

1. Reducing Man-Made Noise (QRM)

Modern homes are filled with electronic devices that emit electromagnetic interference (EMI), commonly referred to as man-made noise (QRM). LED lighting, switching power supplies, smart meters, Wi-Fi routers, and solar inverters all contribute to a high-noise environment. Placing an active antenna too close to the house can significantly degrade its performance by picking up these unwanted signals.

2. Avoiding Conductive Coupling

Active antennas have a high impedance input, making them highly sensitive to nearby conductors. Metal structures, gutters, electrical wiring, and grounded objects near the home can interact with the antenna, leading to unwanted noise pickup or signal distortion. Maintaining a few meters of separation helps minimize this effect.

3. Avoiding Interference from Home Appliances

Common household appliances, such as televisions, refrigerators, and computers, can introduce broadband noise into the RF spectrum. While active antennas are designed to be resistant to some interference, placing them closer than 3 meters to these devices increases the likelihood of degraded performance.

Optimal Distance and Placement

Recommended Minimum Distance: 3 to 5 Meters

For best results, placing an active antenna at least 3 to 5 meters away from the home is ideal. This helps reduce electrical noise while maintaining a manageable cable length for signal transmission. In some cases, even greater distances may be beneficial, depending on the noise environment.

Height Considerations

  • For low-frequency reception (LF, MF, HF), an active antenna should be mounted at a height of 4 to 10 metersto optimize signal reception while avoiding local interference.
  • For higher frequencies (VHF/UHF), height becomes more critical for line-of-sight reception, so placement on a mast or rooftop may be necessary.

Grounding and Shielding

  • Use a properly grounded coaxial feedline (such as RG-58, RG-174, or RG-213) to minimize common-mode noise.
  • Consider a ferrite choke near the receiver to reduce unwanted RF pickup on the coaxial shield.

Practical Installation Tips

  • Use a non-metallic mounting pole (such as fiberglass or PVC) to avoid conductive coupling.
  • Position the antenna away from solar inverters, Wi-Fi routers, and LED lighting.
  • Avoid running the coaxial cable parallel to electrical wiring to minimize noise pickup.
  • Test different locations using a portable receiver to find the quietest spot before final installation.

Conclusion

Maintaining a safe distance of 3 to 5 meters from the home when installing an active antenna is a simple yet effective way to improve signal reception and reduce interference. This setup provides a balance between practicality and performance, ensuring that your active antenna can deliver the best possible results in a typical residential environment.

Written by Joeri Van Dooren, ON6URE – RF, electronics and software engineer, complex platform and antenna designer. Founder of RF.Guru. An expert in active and passive antennas, high-power RF transformers, and custom RF solutions, he has also engineered telecom and broadcast hardware, including set-top boxes, transcoders, and E1/T1 switchboards. His expertise spans high-power RF, embedded systems, digital signal processing, and complex software platforms, driving innovation in both amateur and professional communications industries.