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Takeoff Angle & Radiation Pattern

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What is takeoff angle?▾

Takeoff angle (also called elevation angle) is the vertical angle above the horizon at which most of your antenna's energy leaves the ground — 0° skims out along the horizon, 90° (zenith) goes straight up. For skywave propagation, it's the single biggest factor in how far a signal travels before it comes back down.

DX distance	Typical useful takeoff angle
500–1,000 mi	20–40°
1,000–3,000 mi	10–25°
3,000–6,000 mi	5–15°
6,000+ mi	3–10°

The key idea: a low-angle ray travels farther across the Earth's curved surface before it refracts back down from the ionosphere, so it covers more ground per hop. For long-haul DX, lower is almost always better; for regional contacts (NVIS-style), a high angle straight up is actually what you want.

Antenna

Antenna type

Height above ground (ft)

Common band (optional)

Frequency (MHz)

Ground quality

Ground quality mainly matters for verticals — real ground losses near a vertical's base noticeably raise its low-angle takeoff angle; horizontal-ish antennas (dipoles, inverted-V/V dipoles, Yagis) are driven mostly by height, not ground quality.

Location (optional — shows beam heading on a map)▾

Grid square

Takeoff angle

Elevation pattern (side view)

Azimuth pattern (top-down, compass)

This uses the classic flat-ground image-antenna model (constructive/destructive interference between the direct ray and the ground-reflected ray), the same simplified approach behind ARRL Antenna Book height-vs-takeoff-angle tables — not a full method-of-moments (NEC) simulation with real terrain, so treat the shapes and angle as an estimate, not a precise prediction. Patterns are normalized to a peak of 1 and show relative shape only, not absolute gain.