Grundig in the context of Shortwave

Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (approximately 100 to 10 metres in wavelength). It lies between the medium frequency band (MF) and the bottom of the VHF band.

Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are generally limited by the visual horizon, about 64 km (40 miles).

Mountain bike racing (shortened MTB or ATB racing) is the competitive cycle sport discipline of mountain biking held on off-road terrain. The Union Cycliste Internationale (UCI) recognised the discipline relatively late in 1990, when it sanctioned the world championships in Durango, Colorado. The first UCI Mountain Bike World Cup series took place in 1988. Its nine-race circuit covered two continents—Europe and North America—and was sponsored by Grundig. Cross-country racing was the only World Cup sport at this time. In 1993, a six-event downhill World Cup was introduced. In 1996, cross-country mountain biking events were added to the Olympic Games. In 2006, cross-country mountain biking events became part of the World Deaf Cycling Championships for the first time in San Francisco, USA.

In the United States, there are three USA Cycling Mountain Bike National Calendars: Endurance, Gravity and Ultra-Endurance. USA Cycling runs the USA Cycling Mountain Bike National Championships. There are mountain bike racing types that are not recognized by the UCI, such as mountain bike orienteering that is governed by the IOF.