Editing Shortwave radio (section)

===Data modes===
====CW====
[[Continuous wave]] (CW) is [[on-off keying|on-and-off keying]] of a sine-wave carrier, used for [[Morse code]] communications and [[Hellschreiber]] [[facsimile]]-based [[teleprinter]] transmissions. It is a data mode, although often listed separately.<ref name=FeldHellFAQ/> It is typically received via lower or upper SSB modes.<ref name=RohdeWhitaker2000/>

====RTTY, FAX, SSTV====
[[Radioteletype]], fax, digital, [[slow-scan television]], and other systems use forms of frequency-shift keying or audio subcarriers on a shortwave carrier. These generally require special equipment to decode, such as software on a computer equipped with a sound card.

Note that on modern computer-driven systems, digital modes are typically sent by coupling a computer's sound output to the SSB input of a radio.