What is PSK31?

PSK31, or Phase Shift Keying at 31 baud, is a digital mode used primarily for keyboard-to-keyboard communication in amateur radio. The key characteristic of PSK31 is its low data transmission rate of 31.25 bits per second, which is specifically designed to operate efficiently under poor signal conditions.

This low-rate transmission allows operators to communicate effectively even when the signal is weak or affected by interference, making it a popular choice among amateur radio operators for real-time text communication. The format is particularly optimized for typographical conversations, enabling participants to send and receive text with minimal bandwidth, which is advantageous given the limited resources typically found in amateur radio operations.

In contrast, the other options relate to functionalities or data rates that do not align with the fundamental characteristics of PSK31, emphasizing that its primary focus is on low-rate data transmission.