WSJT-X version 2.4.0 now is available in general release. According to co-developer Joe Taylor, K1JT, WSJT-X version 2.4.0 includes a new digital mode, Q65. This protocol is designed for two-way contacts over especially difficult propagation paths, including ionospheric scatter, troposcatter, rain scatter, TEP, EME, and other types of fast-fading signals.

“On paths with Doppler spread more than a few Hertz, the weak-signal performance of Q65 is the best among all WSJT-X modes,” the Quick Start Guide asserts.

WSJT-X version 2.5.0-rc1 (beta) version has been released. According to the Release Notes, in version 2.5.0 “the Q65 decoder has been enhanced to measure and compensate for linear frequency drift in Q65 signals.”

Q65 uses 65-tone frequency-shift keying and builds on the demonstrated weak-signal strengths of QRA64, a mode introduced to WSJT-X in 2016. Q65 offers user message and sequencing identical to that in FST4, FT4, FT8, and MSK144. It includes a unique tone for time and frequency synchronization. As with JT65, this “sync tone” is readily visible on the waterfall spectral display. In addition, Q65 provides a sensitive “sync curve” near the bottom of the waterfall window.

Testing showed that Q65 will enable stations with a modest Yagi and 100 W or more and to work one another on 6 meters at distances up to ~2000 kilometers on most days of the year, in dead band conditions.

“An excellent example of targeted uses of Q65 is ionospheric scatter on the 6-meter band,” the documentation states. “Extensive tests on the 1,150-kilometer path between K1JT and K9AN have shown that with 300 W power output, nearly every Q65-30A transmission is copied correctly by the other station.” The 30A refers to the transmit-receive period and spacing width.

For the complete announcement and to download the latest version, visit the WSJT-X website.