The useful model: Radiation angle describes the elevation direction of radiated energy relative to the horizon; useful coverage depends on the complete vertical pattern, not one “takeoff angle.”
What controls the result
Height, ground, polarization, frequency, current distribution, terrain, and losses create multiple lobes and nulls. High angles favor many regional/NVIS paths; low angles often favor longer hops.
The misleading shortcut
Quoting the angle of a peak without its lobe width, azimuth, gain reference, and nulls can misrepresent practical coverage.
Make the better decision
Inspect the matching 2D and 3D pattern for the exact installation, compare several elevation sectors, reproduce height and ground assumptions, and confirm with field reports.
Evidence boundary
Propagation and antenna metrics are meaningful only with their frequency, path, geometry, reference plane, loss assumptions, and measurement method. Use current observations and the exact installed system.
