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Section 3 28 jtty
Experimental. JTTY is new — it arrived in the WSJT-X 3.2 release — and this implementation has been checked against the reference off the air only, not off-air. It is here to try, not yet to rely on: treat a decode as worth a second look and a first contact as a test.
Choose JTTY from the DIGITAL row. JTTY is the asynchronous keyboard mode from the WSJT-X 3.2 release: it is worked like RTTY — either side types and sends whenever it likes — but carries forward error correction, so a signal that would be marginal and error-prone as 45.45-baud RTTY still copies. It is about 125 Hz wide, small enough to tuck into a gap in a crowded band.
It is not slotted. Unlike FT8/FT4 there is no even/odd turn and no period to agree on: a transmission starts at any instant and lasts a few seconds, so there is no clock to watch and nothing to synchronise. A message appears in the list a moment after it is heard.
What you see. A rolling log of the messages heard, each with its UTC time,
audio frequency and SNR. The text is what was decoded: a CQ (CQ K1ABC CQ), a
call, a contest exchange (599 123, 1D EMA, 599 FN42), or a control phrase
such as AGN? or TU. A partial message — one whose end was not heard — is
shown dimmed, so a run cut off by the next transmission reads as incomplete.
Transmitting. The TX row under the log is a single line: type the
message (W1ABC W9XYZ FN42, or one of the exchange forms above) and press
TX; CALL CQ fills the box with CQ <your call> CQ and sends it. The
message is sent once — JTTY is asynchronous, so there is no period to wait
for and nothing repeats; the over ends when the burst is done. The message is
packed for the air automatically: a callsign, a contest exchange or a control
phrase is sent as its compact typed form, and anything else is sent as plain
text, so an 11 m CB identifier like 26AT715 goes out as it reads.
Where to find it. There is no calling frequency and the mode is very new; tune where the station you want says it will be, and leave the audio cursor where the signals are — the decoder searches the passband itself.
From the User Manual. Home.