The Hellschreiber or Feldhellschreiber was a facsimile-based teleprinter invented by Rudolf Hell. It has since been emulated on computer sound cards by amateur radio operators; the resulting mode is referred to as Hellschreiber, Feld-Hell, or simply Hell. "Hellschreiber" translates into English as "Light Writer," "Bright Writer," or "Clear Writer," and is a pun on the name of its inventor (Hell (the adjective) is German for "light," the adverb is "bright.")

{play}http://www.pa4rm.com/attachments/068_feld_hell.mp3{/play} Feld Hell test sample
{play}http://www.pa4rm.com/attachments/068_fsk_hell_105.mp3{/play} FSK Hell 105 test sample
{play}http://www.pa4rm.com/attachments/068_fsk_hell_245.mp3{/play} FSK Hell 245 test sample