Plain-language answer: Transequatorial propagation supports VHF and sometimes higher-frequency paths crossing the geomagnetic equator through equatorial ionospheric structure.
Why operators care
It favors particular seasons, local times, endpoints, and geomagnetic geometry and can extend well beyond ordinary line of sight.
What to compare on air
Compare reported paths and time windows with your endpoint geometry, then confirm with beacons or known stations.
The common mistake
Expecting TEP on any north-south path that crosses the geographic equator.
Forecast boundary
Space-weather indices and propagation models describe probabilities and regional conditions. A usable contact still depends on the exact path, time, frequency, antenna pattern, noise, power, and current observations.
