Operating Modes

What Is RTTY? An Introduction to Radio Teletype RTTY is a way for amateur radio operators to send text messages over radio waves. The abbreviation stands for Radio Teletype, and the concept is elegantly simple: text is converted into digital signals and transmitted over HF radio frequencies, where it can be decoded and displayed at the receiving station. Unlike voice transmissions or Morse code, RTTY sends typed messages in a way that can be decoded by specialized equipment or software, making

What Is PSK31? An Introduction to the Digital Mode PSK31, also known as BPSK31 and QPSK31, is a popular computer-sound card-generated radioteletype mode used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat, most often using frequencies in the high frequency amateur radio bands. PSK31 was the first widely adopted HF digital mode to use a computer sound card as the modem, opening the door to the explosion of digital modes that followed. It allows real-time key

What Is JS8Call? An Introduction to the Digital Mode JS8Call is an experiment to test the feasibility of a digital mode with the robustness of FT8, combined with a messaging and network protocol layer for weak signal communication on HF, using a keyboard-to-keyboard style interface. Put simply, it takes the extraordinary weak-signal decoding ability that made FT8 famous and layers on top of it the ability to have actual, free-flowing conversations, send stored messages, and build distributed r

What Is FT4? A Beginner-Friendly Introduction to the Digital Mode FT4 and FT8 are weak-signal-condition digital protocols designed for rapid, accurate communication between amateur radio stations. If you have ever watched the waterfall display in WSJT-X and seen dozens of tiny signals being decoded simultaneously at signal levels far below the noise floor, you have witnessed the magic of this family of modes. FT4 is the faster sibling in that family, built not just for weak-signal performance

What Is Digital Ham Radio? Digital ham radio refers to any form of amateur radio communication that transmits information as digitally encoded data rather than as an unprocessed analog audio or CW signal. In amateur radio, "digital modes" refers to everything that is not phonic (SSB, FM, AM) and not telegraphy. This includes modes such as FT8, RTTY, SSTV, Hell-Schreiben, PSK-31, WSPR, and much more, as well as digital voice transmission modes such as D-STAR, C4FM, DMR, APCO, P25, M17, and other