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WSJT-X caution

Len Member
K1JT Advises WSJT-X Users Not to Use “Unauthorized” Builds of His Software TAGS: Laureate Joe Taylor, new mode, WSJT software suite

Nobel Laureate Joe Taylor, K1JT, the developer of the popular WSJT “weak-signal communication” software suite is advising users to avoid what he called “unauthorized” versions of his software. He said problems could result by using these builds on the air, and any results that might be shared with the broader user community would be unhelpful.

“Third-party individuals — ie, others not part of the WSJT development team — have been compiling WSJT-X from the open-source code and making unauthorized ‘releases’ of their builds,” Taylor said September 8 in a discussionof WSJT-X “fast modes” on his website. “I do not recommend use of these builds on the air. If you operate with one of these unauthorized ‘rXXXX’ code revisions in our experimental code branch, you have no idea what you've got.”

Taylor said that such programs “quite possibly” have been built from an intermediate, temporary “save” of various files that were not intended to produce a usable program. Subsequent observations regarding what does or does not work, he said, then become “worse than useless. [T]hey waste your time and ours.”

WSJT-X implements JT9, which Taylor has described as “a new mode optimized for weak-signal communication on the LF, MF, and HF bands.” Taylor said JT9 is about 2 dB more sensitive than JT65 while using less than 10 percent of the bandwidth. WSJT-X is an “experimental” or “extended” package.  Plans call for the eventual inclusion of other popular modes now supported in WSJT.

A new alpha release of experimental WSJT-X v1.6.1, r5865, includes major improvements to the JTMSK decoder.

Taylor also recently posted information about new “Fast JT9” submodes for meteor-scatter communication on 28 and 50 MHz. The post includes a brief development history and instructions.

“Since its origin in the dark ages (ca 2001) WSJT has supported ‘fast’ modes (designed for meteor scatter, etc) and ‘slow’ modes (optimized for EME and other weak-signal propagation types),” he said. “The most recent new mode, JT9, now has both fast and slow submodes.”

He said the new, experimental JT9 submodes use the same message structure, encoding, and modulation type as JT9A (the original version), but wider tone spacing and optional faster keying rates. Among other improvements, it features a 5× speed increase for the fast JT9 decoder.

More information on the WSJT software suite is available on Taylor’s website.



  • M0GVZ
    M0GVZ Member
    edited December 2018
    From the K1JT website:

    "WSJT, MAP65, WSPR, WSPR-X, and WSJT-X are open source programs distributed under terms of the GNU General Public License."

    WJST-X is released under the GNU General Public License. This license guarantees end users (individuals, organizations, companies) the freedoms to run, study, share (copy), and modify the software.

    Therefore under the GNU Public License they are free to modify the software and release their own builds with the only stipulation being they must also be released under the GNU Public License. There are therefore no "unauthorised versions" of his software as no authorisation needs to be sought from the original creator to share or modify it. There may be versions that he hasn't coded but by licensing under the GNU Public License he cannot control what people do with the source code.

    Perhaps before pointing fingers and effectively calling people out for ripping off software, K1JT should actually read the license terms of the licenses that he applies. When you release under the GNU Public License you effectively sign away all rights.
  • DrTeeth
    DrTeeth Member ✭✭
    edited August 2016
    I do not believe that Joe has done anything of the sort at all and you have accused him of saying things that he has not (e.g. "ripping off" - which means passing off as one's own). All he suggests is that you use versions that are released by the original authors or self-compiled from the original source. To do otherwise makes support much more difficult and there may have been unknown changes made to the source before the compile.

    There are many smart people working on this program and the open source nature of the licence aids the collaborative effort.

    Just read the release *carefully* and take a chill pill.
  • KY6LA_Howard
    KY6LA_Howard Member ✭✭✭
    edited January 2017
    Guy is correct Joe is just advising people that some of the third party compiles are dangerous and are impossible to support
  • Ned K1NJ
    Ned K1NJ Member ✭✭
    edited December 2016

       Joe has graciously supplied the code.  He advises that you assume a possibly
    high level of risk that is beyond his control.

    Ned,  K1NJ

  • k3Tim
    k3Tim Member ✭✭✭
    edited May 2020
    I tend to NOT correct Nobel Laureate.  In fact can't recall the last time I did.

    After reading thie topic decided to give WSJT-X a try.  Downloaded the official release, read some previous helpful comments from this Community and was on the air without major hassles.  Tried to use direct IP but kept getting a time out.  Read it sometimes helps to stop the WJ program and relaunch.  That did the trick.  First QSO to a JA on 40 meters.


  • M0GVZ
    M0GVZ Member
    edited September 2015
    "unauthorised versions" is terminology used by software companies to usually mean pirated....

    There can be no such thing as unauthorised versions for the reasons he gave under the GNU public license.
  • M0GVZ
    M0GVZ Member
    edited September 2015
    "I tend to NOT correct Nobel Laureate."

    Why not? Only a foolish person wouldn't if that Nobel Laureate was wrong. Being a Nobel Laureate does not make you infallible, does not mean you do not make mistakes, it does not make you superhuman knowing of all things. President Obama is a Nobel Laureate, has he made mistakes?

    Joe got his Nobel prize in physics for a joint astronomical discovery, that does not mean he's an expert on software licensing.
  • Jay Nation
    Jay Nation Member ✭✭
    edited May 2019
    "I" think Joe Taylor is just making the recommendation that you should either stick to the "Official" releases or Compile your own. you have no way of knowing what has been added to unofficial executables, when you don't know where the source came from.

    Sourceforge also hosts the JTSDK project which makes compiling your own copy a simple task.

    73, Jay - NO5J 
  • DrTeeth
    DrTeeth Member ✭✭
    edited August 2016
    If you cannot see the difference between those two types of Nobels Laureate and the intelligence of the people to whom they were awarded and why, it may be best to stay schtum LOL.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    Thank you for posting the caution from K1JT.

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