How does RTTY work? The continued discussion in our community about Digital Modes got me thinking about what a Digital Mode actually is. At the most fundamental level, it's about encoding information into discrete chunks to exchange information. Morse Code is an example of a Digital Mode, made up from combinations of dits and dahs. This week I look at how RTTY works. Foundations of Amateur Radio is a weekly podcast about the 1000 hobbies that make our community. You can listen on-air, on-line or on-demand. Get your own personal copy from the website at http://podcasts.itmaze.com.au/foundations/, or search for my callsign VK6FLAB on iTunes, Google, or your personal podcast directory for your weekly fix. Onno VK6FLAB
In the U.S. and elsewhere the RTTY default standard is 2125 Hz-170 Hz (shift)=1955 Hz, the mark and space tones, with a speed of 45.45 baud. It's a really fun mode but it has no (FEC) forward error correcting and can get beat up by lightning crashes and radio wave propagation vagaries.
For some reason, I find it humorous that SSB-based FSK has a "standard" that specifies audio frequencies.
