VerticalVortex: The Heavy-Duty Ground-Mounted E-Probe for 160–40M
The VerticalVortex is the flagship ground-mounted E-probe receiver in the RF.Guru RX antenna lineup. Purpose-built for the low HF bands, it is optimized for 160, 80, and 40 meters—frequencies that demand superior low-noise reception and high tolerance to local RF fields. While it shares much of its topology with the EchoTracer, the VerticalVortex is significantly more rugged, larger, and engineered for the challenges of QRO transmit environments.
Physical Design
At the heart of the VerticalVortex is a 6-meter tall, 35 mm diameter aluminum element, which acts as a massive electric field probe. Ground-mounted and physically isolated, this vertical offers substantial signal pickup while maintaining high rejection of local E-field noise through smart filtering, grounding, and amplifier linearity.
High Power Immunity: QRO-Proof
What truly sets the VerticalVortex apart is its integrated RF sensing and protection circuit, which enables it to survive nearby 1 kW transmissions at just 10 meters distance. This is achieved by:
- Using a fast RF detector (comparator + clamping relay)
- Temporarily grounding the amplifier input during TX events
- Using robust series RF protection and resettable elements
This makes the VerticalVortex ideal for SO2R setups, high-power contest stations, and anyone who operates serious TX gear and still needs clean RX data from a close-by antenna.
Architecture Highlights
- Receive Element: 6m x 35 mm aluminum vertical probe
- Input Protection: TVS diodes + PIN limiter + RF relay
- Amplifier Core: MMIC front end
- Relay Control: Onboard RF power detector using TLV3011 comparator
- Output Drive: Buffered output via filtering
Performance Specifications
| Parameter | Value |
|---|---|
| Frequency Range | 100 kHz – 30 MHz |
| Optimal Bands | 160, 80, 40 meters |
| Noise Figure | < 1 dB (below 10 MHz) |
| RF Protection | Up to 1 kW @ 10 m |
| Output IP3 (OIP3) | +36 dBm |
| P1dB | > +18 dBm |
| CM Isolation | > 20dB |
| Supply Voltage | 10–15 VDC |
| Current Consumption | ~90 mA |
| Output Impedance | 50 ohms |
VerticalVortex vs. EchoTracer
While the EchoTracer is a compact, pole-mountable E-field probe for general HF use, the VerticalVortex is its heavy-duty cousin:
- Much larger receive element means more signal pickup and wider spatial sensitivity
- Ground-mounted to minimize local re-radiation pickup
- Integrated TX detection for seamless coexistence with high-power stations
This added size and protection also make the VerticalVortex more prone to strong E-fields, but thanks to its RF-triggered disconnect mechanism, it handles them without degrading performance.
Ideal Applications
- Contest stations needing close-in RX antennas
- RX-only phased arrays on 160/80/40 meters
- Noise-prone environments needing vertical polarization capture
- DXers operating high-power TX and requiring clean RX without switch-over delays
- Companion for phased RX arrays (QuadraTus compatible)
Conclusion
The VerticalVortex sets the standard for robust E-probe design in demanding HF applications. Its ability to withstand nearby QRO transmission, combined with its low-noise amplifier and massive vertical element, make it the go-to antenna for serious operators who need reliable RX performance under high-RF conditions.
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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.