access to international HF frequencies often gain their first experience with truly long-distance communications on the 6 meter band. Many of these operators develop a real affection for the challenge of the band, and often continue to devote much time to it, even when they gain access to the HF frequencies after upgrading their licenses. For antennas, horizontal polarization is used for 6 meter weak signal, SSB communications using tropospheric propagation, sporadic-E, and multi-hop sporadic-E, and for other propagation modes where polarization does not matter as much. Vertical polarization is customarily used for local FM communications, repeaters, radio control. Common uses AM simplex (direct, radio-to-radio communications) FM simplex (direct, radio-to-radio communications) FM repeater operation Earth-Moon-Earth communication Sporadic E propagation Aurora Borealis reflection WSJT digital modes Packet radio SSB voice operation Morse code (CW) operation DX Radio control Radio control hobby use In North America, especially in the United States and Canada, the 6-meter band may be used by licensed amateurs for the safe operation of radio-controlled (RC) aircraft and other types of radio control hobby miniatures. By general agreement among the amateur radio community, 200 kHz of the 6 meter band is reserved for the telecommand of models, by licensed amateurs using amateur frequencies. The sub-band reserved for this use is 50.79–50.99 MHz with ten "specified" frequencies, numbered "00" through "09", spaced at 20 kHz apart from 50.800–50.980 MHz. The upper end of the band, starting at 53.0 MHz, and going upwards in 100 kHz steps to 53.8 MHz, used to be similarly reserved for RC modelers, but with the rise of amateur repeater stations operating above 53 MHz in the United States, and very few 53 MHz RC units in Canada, the move to the lower end of the 6 meter spectrum for radio-controlled model flying activities by amateur radio operators was undertaken in North America, starting in the early 1980s, and more-or-less completed by 1991. It is still completely legal for ground-level RC model operation (cars, boats, etc.) to be accomplished on any frequency within the band, above 50.1 MHz, by any licensed amateur operator in the United States; however, an indiscriminate choice of frequencies for RC operations is discouraged by the amateur radio community via its self-imposed band plan for 6 meters. In the United States, the Federal Communications Commission's (FCC) Part 97.215 rules regulate telecommand of model craft in the amateur service within the United States.