Amateur radio operators who specialize in making two way radio contact with other amateurs in distant countries are also referred to as DXers. On theHF ,also known as shortwaveamateur bands, DX stations are those in foreign countries. On the VHF and UHF amateur bands, DX stations can be within the same country or continent, since making a long-distance VHF contact, without the help of a satellite, can be very difficult. DXers collect QSL cards as proof of contact and can earn special certificates and awards from amateur radio organizations.