Keyboard Modes for the 500 kHz band

John W1TAG has a useful webpage describing keyboard modes for use on the 500 kHz (600 metres) band.

The page has descriptions and spectragrams of tests carried out on 500 kHz during November and December 2007 using 16 different data modes.

Keyboard Modes for 600 Meters
http://www.w1tag.com/600M_Modes.htm