Open-Source Hardware
This is a hobbyist-grade, open-source device. It offers incredible value and capability, but requires a hands-on approach and a willingness to experiment.
Fleetwood Digital
5.6M SOTA/POTA Portable HF Antenna | Red Base Edition (300W)
5.6M SOTA/POTA Portable HF Antenna | Red Base Edition (300W)

Description
The 5.6M SOTA/POTA Portable HF Antenna (Red Base Edition) is an ultra-portable, $1/4$-wavelength vertical antenna designed for rapid deployment in the field. Unlike matched-coil antennas, this system contains no fragile internal tuning circuits, achieving resonance purely through the physical length of the extended whip. While its highly compact breakdown size makes it popular among QRP operators, this direct-connection design allows it to safely handle up to 300 Watts of continuous RF power—making it the perfect companion for 100W mobile radios during Parks on the Air (POTA) activations.
⚠️ Mandatory Operation Warnings
This is NOT an Auto-Tuner: The red base is a heavy-duty junction block connecting your coax, whip, and ground. To tune the antenna for different bands (e.g., from 20m down to 10m), you must physically collapse or extend sections of the silver whip.
Hardware Protection: When driving the ground spike into hard soil, do not leave the red base attached and hit it with a hammer. Hammer the stainless steel spike into the ground first, and then screw the red base onto the top of the spike.
Radial Wire Handling: The included radial wire (counterpoise) is uniquely constructed from a multi-strand flat ribbon cable kept bonded together as a single wide unit. Do not peel or separate the individual strands; this flat ribbon design creates a larger surface area for capacitive ground coupling.
Performance & Engineering Highlights
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📻Native 20m to 10m Coverage The fully extended 5.6-meter (18.3 feet) whip acts as a resonant $1/4$ wave vertical on the 20-meter band (14 MHz). By manually collapsing sections, operators can easily tune the 17m, 15m, 12m, and 10m bands.
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⚡High Power Handling Because there are no fragile capacitors or resistors inside the red base block, this antenna can safely handle 300 Watts of continuous RF power, and up to 600W Peak SSB.
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🏕️Rapid Field Deployment The complete kit includes the M10 threaded ground spike, the Red Base SO-239 junction block, the flat ribbon radial, and the telescopic whip for a fast, tool-free setup in dirt or sand.
Technical Specifications
| Product Model | 5.6M SOTA/POTA Portable HF Antenna (Red Base Edition) |
|---|---|
| Frequency Range (Native) | 14 MHz to 30 MHz (20m, 17m, 15m, 12m, 10m) |
| Wavelength | $1/4$ Wave Vertical |
| Maximum RF Power | 300 Watts (Up to 600W Peak SSB) |
| Fully Extended Length | ~5.6 Meters (18.3 feet) |
| Base Connector (Radio) | SO-239 (UHF Female) |
| Hardware Thread Size | Standard M10 threads |
Downloads & Resources