2642WSJT Version 5.9
- Nov 16, 2005To: Users of WSJT
From: Joe Taylor, K1JT
Subject: WSJT 5.9.0
Date: November 16, 2005
I am pleased to announce that WSJT 5.9.0 is available for free download
from the WSJT Home Page, http://pulsar.princeton.edu/~joe/K1JT. It
should appear soon on the European mirror site, http://www.dk5ya.de, as
well. This is a major upgrade, not a beta release. If you use WSJT,
you should definitely upgrade to version 5.9.0.
I believe that all reported bugs found in beta-release version 5.8.6
have been fixed. In addition, WSJT 5.9.0 is better than previous
versions in a number of significant ways. The JT65 decoder is
significantly faster. You can double-click on the waterfall or on the
"red line" to decode a transmission quickly at any selected DF. The
range of DT values searched for proper synchronization has been doubled.
Errors in soundcard sampling rates are corrected. New graphical
information is provided for JT65 shorthand messages. Temporary add-on
DXCC prefixes are accommodated. Tracking information for a radio source
at specified RA and DEC (e.g., a pulsar or a deep space probe) is
provided. New operational features designed for random and
contest-style operation are available. The full source code for WSJT
will soon be made available under the GNU General Public License
(programmers, see more information below).
A more complete description of enhancements to WSJT since version 5.8.6
can be found at http://pulsar.princeton.edu/~joe/K1JT/UpdateHistory.txt.
There are many program changes, so be sure to read this information
carefully before trying to use WSJT 5.9.0!
Of course there may be some new bugs, and perhaps I have overlooked an
existing problem that you already know about. Please let me know if you
find shortcomings in version 5.9.0, or if you have suggestions for
Sorry, I have not yet found time to implement EME Echo mode. When that
is done, and when I have finished some further enhancements to the
decoders, WSJT 6.0 will be born. With some luck, there may also be a
new User's Guide at about that time.
With best wishes,
-- 73, Joe, K1JT
Additional Information for Programmers
WSJT versions 5.8+ are the result of a complete re-write of the user
interface, timing control, and audio I/O portions of WSJT 4.9.8. My
principal motivation for this major effort was to make the program
multi-threaded, both for real-time operational convenience and for
performance reasons. Another strong motivation was a desire to move
the program away from its dependence on a proprietary compiler
(Microsoft Visual Basic) and a single computer platform (Windows).
The user interface of WSJT 5.8+ is written in Python -- an elegant,
open, cross-platform language that has been a pleasure for me to
learn. The remainder of the program is written mostly in Fortran,
with some routines coded in C; much of that code has been carried over
directly from WSJT 4.9.8.
I plan soon to release the source code for WSJT under the GNU General
Public License (GPL). To this end, I have separated out the one piece
of proprietary code formerly in the program, the soft-decision Reed
Solomon decoder licensed from CodeVector Technologies (CVT). A driver
for this decoder, optimized for JT65, has been compiled to make a
stand-alone executable KVASD.EXE that is now distributed as part of
the WSJT installation package, but is not part of WSJT itself. With
this approach I can honor all provisions of the CVT license, and at
the same time release everything else as an open source program under
WSJT 5.9.0 includes an open source hard-decision Reed Solomon decoder
based on code written by Phil Karn, KA9Q . WSJT uses this decoder
automatically if the proprietary CVT decoder is unavailable. In such
instances "deep search" decoding retains its full sensitivity, but
fully general decoding independent of the callsign database is less
sensitive by 2 or more dB, depending on signal fading characteristics.
Separation of the program into two executable units is transparent to
WSJT 5.9.0 uses the following open source libraries, which are also
available under the GPL:
1. FFTW, by Matteo Frigo and Steven Johnson, for computing Fourier
2. "Secret Rabbit Code" or "libsamplerate", by Erik de Castro, for
accomplishing band-limited resampling of data
3. RS, by Phil Karn, KA9Q, for Reed Solomon encoding and
I hope that the open release of WSJT source code will encourage others
to read and understand the code, get involved in improving WSJT, and
perhaps porting it to other platforms. Versions of the CVT
soft-decision decoder for Linux or Macintosh will be easy to compile
and distribute, if there is demand for them.
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