Near-vertical incidence skywave fills the gap between where groundwave dies and where normal HF skip lands. You get it by putting a horizontal wire low, so it fires almost straight up.
Hang a wire low so it fires straight up and fills the skip zone.
Near-vertical incidence skywave covers the gap between where ground wave dies out and where normal HF skip lands — roughly 0 to 300 miles.
NVIS depends on the ionosphere, which changes with time of day and the solar cycle — the usable frequency drifts, so plan a day and night band.
