What it means on the air: RTTY is radio teletype, a digital text mode traditionally using frequency-shift keying between mark and space tones, now commonly generated and decoded by computer software.
Why operators use it
Operating conventions, shift, baud rate, polarity, audio-versus-FSK keying, filters, and frequency display differ among radios and software.
Where the contact goes wrong
A reversed or overdriven signal may look active but decode poorly, and running full rated SSB power can overheat the station during long transmissions.
A cleaner operating method
Select the correct RTTY standard and sideband convention, align filters, set clean mark/space levels, confirm polarity, use an appropriate duty-cycle power, and exchange concise text.
Operating boundary
Use current software and radio documentation, published band plans, applicable licensing rules, and the lowest power that closes the path. A decode, map position, or automated exchange does not by itself prove end-to-end communication.
