To: Users of WSJT-X
From: Joe Taylor, K1JT
A new revision of the experimental program WSJT-X has been posted. As
usual, a link to it appears on the WSJT web site:
http://physics.princeton.edu/pulsar/K1JT/wsjt.html
The following is a direct link to the installation file:
http://physics.princeton.edu/pulsar/K1JT/WSJTX_05r2783.exe
This revision has an unusually large number of changes relative to the
previous release, v0.4 r2746. These changes include:
1. PTT control via COM ports COM10 and higher is enabled.
2. Improved decoder performance: higher speed as well as better chances
of success. Moderate amounts of frequency drift are detected and
compensated. Computed S/N values are more reliable. Time offsets from
-2.5 to +5 s are now supported, which makes JT9 usable for EME. (EME
tests on 144 MHz have been successful, and performance on that
propagation mode appears to be good.)
3. Tx Frequency now tracks the selected QSO Frequency (unless you hold
down the CTRL key when setting QSO Frequency via mouse-clicks or the
F11/F12 keys).
4. Decoded text containing "CQ " is highlighted with green background;
text including "MyCall" is highlighted in red.
5. In previous versions, signal reports were required to be in the range
-30 to -01 dB. In v0.5 r2782 the range has been extended to -50 to +49
dB. There is backward compatibility for the range -30 to -01, but
reports in the range -50 to -31 and 0 to +49 will NOT be decoded
correctly by previous program versions. It is important to upgrade!
6. Items "Save Synced" and "Save Decoded" are now implemented.
7. UTC Date, JT9 submode, and a parameter related to the decoding
procedure are now included in file wsjtx_rx.log.
8. Editing of Tx messages (in any of the six Tx message boxes) is
complete when you hit "Tab" or "Return". The message is then parsed and
converted to the form in which it will be displayed if decoding is
successful. Free-text messages are trimmed to 13 characters and
highlighted with a pink background.
9. The most recent transmitted message is displayed in the right-most
label on the status bar. This can be useful if you have lost track of
where you were in a QSO.
10. By default, the program now starts with Monitor ON. An option on
the Setup menu allows you to select "Monitor OFF at startup".
11. Better scaling is provided for the red "JT9 Sync" curve. Note that
JT9 signals in the active sub-mode should appear in this plot as a bump
of width equal to the total signal bandwidth, with a narrow and slightly
higher bump at the left edge. The narrow bump is the frequency of the
Sync tone, which is defined as the nominal frequency of the JT9 signal.
12. Basic QSO information is now written to file wsjt.log when you click
the "Log QSO" button.
13. The WSJT-X User's Guide has been updated.
14. Other known bugs have been fixed. There will probably be new ones!
When you find one, or if you know of any old ones that have NOT been
fixed, please send me email.
Summary of Present Status
----------------------------------------------------------------------
I believe that WSJT-X is now a stable and very usable program. Many
thousands of QSOs have been made with JT9-1, mostly at HF -- I have made
nearly 100, myself. Also a number of QSOs have also been completed at
MF, and successful tests have been made on 2m EME, etc. A number of
QSOs have also been made with JT9-2.
As far as I know the slower modes (JT9-5, JT9-10, and JT9-30) also work
correctly. (Certainly they do in my laboratory test setup.) Most
people will find these modes too slow for "everyday" use, and they
require high frequency stability. It remains to be seen whether they
will be widely used.
An alternative approach to obtaining improved sensitivity would be to
give the decoder an ability to average over several successive
transmissions. For example, the average of five JT9-1 transmissions
could reach a decoding threshold around -32 dB, only 2 dB worse than a
single JT9-5 transmission. Because of QSB, the shorter transmissions
may actually succeed in less total time. Stability requirements would
be those of JT9-1, much less stringent than those of JT9-5.
Program development is not finished, by any means. I will be grateful
for your feedback on performance issues, as well as your "wish-list" of
features to be added. As always, example recordings of files that you
think should have decoded, but did not, will be much appreciated.
I hope to find time for more work on WSJT-X soon. Later this week,
however, my radio time will be focused primarily on the ARRL
International EME Contest.
With best wishes,
-- 73, Joe, K1JT
|
