Mounting the Vertical Vortex

 

The Vertical Vortex is an E-probe active antenna designed for high-impedance voltage sensing. When mounting the antenna, grounding and capacitive coupling play a crucial role in performance. In most cases, a single wire ground connection is sufficient, but when mounted above a conductive surface like a steel roof, additional considerations apply.

1. Standard Grounding (Single Wire Connection)

For most installations, the Vertical Vortex only requires a single direct ground connection to a conductive structure, such as a radial system, a ground rod, or a conductive mast. This connection establishes a stable ground reference for the E-probe and ensures proper operation.

2. Mounting Above a Conductive Surface (Steel Roof)

When mounting the Vertical Vortex above an effective ground plane, such as a steel roof, direct grounding is not always required. Instead, the antenna can utilize capacitive coupling with the surface below.

Installation Considerations:

  • Direct Physical Connection (Preferred Approach)
    • If possible, attach the ground terminal of the Vertical Vortex directly to the steel roof using a conductive strap or wire.
    • This ensures a stable RF ground reference, improving performance and minimizing noise pickup.
  • Capacitive Coupling via a Metal Plate (Alternative Approach)
    • If a direct connection is not feasible due to paint, insulation, or gaps, place a stainless steel (RVS) platedirectly beneath the probe.
    • A 1m² plate is generally sufficient for operation in the 160m–40m bands (1.8–7.3 MHz).
    • The plate improves capacitive coupling and stabilizes signal reception.
  • Height Above the Ground Plane
    • If the E-probe is mounted too high above the metal surface (e.g., >1 meter), capacitive coupling weakens, reducing efficiency.
    • Keeping the probe within 50 cm of the surface ensures strong capacitive coupling.

3. Testing and Optimization

  • First, test performance with a single direct ground wire connection.
  • If performance is inconsistent, try adding a 1m² RVS plate beneath the probe.
  • If additional grounding is needed, extend the plate or connect it to the steel roof for better coupling.

Conclusion

  • For standard installations, a single wire ground connection is sufficient.
  • For installations above a conductive ground (e.g., steel roof), direct grounding is preferred.
  • If direct grounding is not possible, a 1m² metal plate provides sufficient capacitive coupling.
  • Proper placement (close to the surface) ensures optimal performance.

By following these guidelines, the Vertical Vortex will perform optimally in all installation scenarios.

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.