TV and FM DX - Transequatorial Propagation (TEP)

Transequatorial Propagation (TEP)

Discovered in 1947, transequatorial spread-F (TE) propagation makes it possible for reception of television and radio stations between 3,000–5,000 miles (4,800–8,000 km) across the equator on frequencies as high as 432 MHz. Reception of lower frequencies in the 30 – 70 MHz range are most common. If sunspot activity is sufficiently high, signals up to 108 MHz are also possible. Reception of TEP signals above 220 MHz is extremely rare. Transmitting and receiving stations should be nearly equidistant from the geomagnetic equator.

The first large-scale VHF TEP communications occurred around 1957 – 58 during the peak of solar cycle 19. Around 1970, the peak of cycle 20, many TEP contacts were made between Australian and Japanese radio amateurs. With the rise of cycle 21 starting around 1977, amateur contacts were made between Greece/Italy and Southern Africa (both South Africa and Rhodesia/Zimbabwe), and between Central and South America by TEP.

"Afternoon" and "evening" are two distinctly different types of trans-equatorial propagation.