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Set up an HF station with an NVIS antenna

HF signals reflect off the ionosphere, so they reach hundreds or thousands of km with no ground network. A low NVIS antenna fills the gap between local VHF and distant HF contacts.

How

1. Check your licence privileges. US example: Technicians have only limited HF access (mainly CW and the 10 m band, 200 W PEP limit), so General class is the practical HF licence. UK example: Foundation 25 W PEP, Intermediate 100 W PEP, Full 1,000 W PEP in primary bands.
2. Choose a 12 V HF transceiver so it runs straight from the comms battery. Check the manufacturer's current draw on transmit.
3. For regional contacts (roughly 0 to 300 miles in Finch's NVIS article), use a dipole cut for the 80 m or 40 m band, mounted low (up to about one eighth of a wavelength above ground). Finch gives about 120 ft long at 30 ft high for 3.9 MHz.
4. Use lower HF bands at night and higher ones by day; the usable frequency drops in daytime and rises at night, as Finch describes.
5. Expect HF disruption during solar storms; NOAA SWPC notes flare blackouts on the sunlit side and polar blackouts during radiation storms.
6. Practise on local nets every week so the station is known to work.

Safety: Never put up an antenna where it could fall onto or touch power lines.

Do these first

• comms-11

Sources

1. US Amateur Radio Frequency Allocations. ARRL, accessed 2026-11
2. Updating the amateur radio licensing framework: overview of key changes. Ofcom (UK), accessed 2026-11
3. NVIS: Near Vertical Incidence Skywave (S. C. Finch, AI0W, 2008). QSL.net (author's article), accessed 2026-11
4. HF Radio Communications. NOAA Space Weather Prediction Center, accessed 2026-11
5. The Rebirth of HF (white paper). HamSCI / Rohde and Schwarz (P. Denisowski), accessed 2026-11

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