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WSJT-X/UpdateHistory.txt
Joe Taylor 88d42d608c 1. Replaced README.TXT and README_592.TXT with UpdateHistory.txt. 
2. Improved the listing of add-on DXCC prefixes.


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Changes in WSJT 5.9.3: January 26, 2006
---------------------------------------
This is a minor maintenance release.
1. New Help screen provides a list of available suffixes and add-on
DXCC prefixes.
2. The occasional error message about "images do not match" has been
trapped and should no longer occur.
3. Code that required one's own grid locator to be entered with first
two letters in upper case, last two in lower case, has been made
case insensitive (as it should have been).
4. Initialization of the PTT line to the "OFF" state has been fixed.
Changes in WSJT 5.9.2: January 16, 2006
---------------------------------------
Enhancements
------------
1. Thread priorities have been adjusted for smoother operation.
2. The JT65 decoder has been given improved immunity to garbage data
(birdies, QRM, etc). It exhibits better performance on strong
signals and provides more accurate estimates of their S/N.
3. The FSK441 decoder produces less on-screen gibberish when
processing mouse-picked decodes.
4. The JT6M decoder now makes better use of Freeze and Tol. You can
set the value of "Freeze DF" by using the Right/Left arrow keys.
(This feature is also useful in JT65 mode.)
5. On-screen font sizes can be set by using Windows Notepad to edit
the file wsjtrc.win. If your screen has resolution greater than
1024 x 768, or if you have old eyes like mine, you may want to
increase the font sizes from 8 and 9 points (first three lines of
the file) to, say, 9 and 10 points.
6. A simulator mode is now built into WSJT for testing purposes. It
is presently most useful in JT65 mode. By entering, say, "#-22"
in the text box for Tx6, you signify that the program should
generate its Tx audio files with the signal embedded in white
gaussian noise, 22 dB below the noise power in a 2.5 kHz
bandwidth. You can direct this signal into a second computer
running WSJT, for example to test the decoder or to practice
operating in JT65 mode. You can even have the two computers "work
each other" in a simulated QSO, although changing messages of
course requires operator action.
7. Dividing lines are now provided on the waterfall display between
spectra corresponding to wave files read from disk.
8. The PTT line is explicitly set low on program startup.
9. The F10 key brings up the SpecJT screen (if it was hidden) and
toggles foreground and focus status between the WSJT and SpecJT
screens.
10. You can use the Alt-F and Alt-Z keyboard shortcuts to toggle
"Freeze" and "Zap" on and off.
11. "Accelerated decoding" has been removed from the Setup menu. In
effect, this option is now always ON.
12. Text windows are now cleared when switching between modes.
13. Linux and FreeBSD versions (see below) offer PTT control via
parallel port, as well as serial port. They offer sound support
via ALSA and OSS.
Bug Fixes:
----------
1. The use of non-threadsafe code for FFTs could cause occasional and
unpredictable program crashes. Fixed.
2. A bug in the JT65 decoder could (rarely) cause large errors in the
reported level of strong signals. Fixed.
3. The program could be made to crash by trying to read a very short
wave file. Fixed.
4. "Save None" now works as it should.
Please note:
------------
When entering your grid locator on the Setup->Options page, use upper
case for the first two letters and lower case for the last two. For
example, for K1JT the locator is FN20qi.
For Curious Users, and Especially for Programmers
-------------------------------------------------
WSJT is no longer a one-person effort, and the program no longer runs
only under Microsoft Windows. WSJT is now a full-fledged Open Source
project, with an active working group making contributions to future
development. Source code is now stored in a public repository under
control of a version control system called "Subversion," or SVN. You
can learn more at http://developer.berlios.de/projects/wsjt/.
The first significant result of the group effort has been to create
versions of WSJT that run under the Linux and FreeBSD operating
systems. Porting WSJT to the Macintosh platform should be
straightforward, but has not yet been done.
If you are interested in testing and using WSJT on your own Linux or
FreeBSD system, we'd like to hear from you. Please note that the
present Linux and FreeBSD versions are intended mainly for
programmers. You need to know your way around these operating
systems to be able to install them.
If you feel that you can usefully contribute to the future development
of WSJT on any platform, we would also like to hear from you! We
could use help with documentation and website maintenance, as well as
actual programming.
The present WSJT working group consists of:
Diane Bruce, VA3DB
James Courtier-Dutton
Bob McGwier, N4HY
Jonathan Naylor, ON/G4KLX
Stewart Nelson, KK7KA
Joe Taylor, K1JT
Kaj Wiik, OH6EH
Changes in WSJT 5.9.0: November 16, 2005
------------------------------------------
1. JT65 decoding has been made faster and significantly improved in
other ways. Three new options appear on the Decode->JT65 menu:
"Fast", "Normal", and "Exhaustive". The program is most sensitive
if you choose "Exhaustive". Choosing "Normal" will make decoding
slightly less sensitive, but the loss is not great, and decoding
can be twice as fast. The "Fast" setting is faster still, but can
be less sensitive by 2 dB or more in some cases. If you have a 1.5
GHz or faster computer, use "Exhaustive". With a slower computer
you may want to experiment with the other settings.
2. In JT65 mode, double-clicking on the waterfall (SpecJT window) or
on the red curve (main window) sets "Freeze DF" to the selected
frequency, turns Freeze ON, sets Tol to 50 Hz, and invokes the
decoder. Using this feature, you can quickly decode a transmission
at several different values of DF. I find this feature to be
*extremely* useful.
3. The range of DT values searched to establish synchronization has
been doubled, now extending from -2 to +10 seconds. The reported
values of DT are more accurate, as well. You should normally
expect EME signals to have DT in the range 2 to 3 seconds, but the
program will now synchronize properly even if DT is well outside
this range.
4. WSJT now offers the ability to correct for errors in soundcard
input and output sampling rates. Numbers displayed in the first
panel of the status bar (at lower left of the main screen) give the
ratio of actual sample rates for input and output to the correct
value, 11025 Hz. The numbers should stabilize within about one
minute after program startup. If they fall in a "safe" range
between about 0.9990 and 1.0010, you have a good sound card (at
least in respect to sampling frequency). You can then leave the
entry fields "Rate In" and "Rate Out" on the "Setup -> Options"
page at their default values, 1.0.
If your soundcard gives one or both numbers well outside the safe
range, you should enter the displayed errant numbers as "Rate In"
and/or "Rate Out" on the Setup->Options page. This needs to be
done only once; subsequent changes in the last decimal place of the
displayed values are not very significant, and can be safely
ignored.
The result of this procedure is that your Tx signal will be
"trimmed" so that your tone spacings in time and frequency are more
nearly correct. In addition, your digitized Rx signals will be
adjusted so that the software can properly interpret them.
This trimming is an important procedure. Some recent sound cards
produce sampling error factors as low as 0.9932 or as high as
1.0068. If uncorrected, such results can degrade your S/N in WSJT
modes by 2 dB or more.
If one of the measured sample rates differs from the corresponding
value specified for "Rate In" or "Rate Out" by more than 0.1%, a
red warning label will appear just below the graphical area on the
main screen.
5. The graphical display of information obtained during JT65 decoding
has been enhanced. As before, a red line illustrates the maximum
correlation between the pseudo-random sync tone pattern and the
received signal at each value of frequency offset, DF. A blue line
shows the correlation at the best DF, plotted as a function of time
offset, DT. If a shorthand message is detected, two new lines
colored magenta and orange replace the red and blue lines. The new
lines illustrate phase-resolved spectra measured in each of the two
phases of the shorthand square-wave pattern. A properly detected
shorthand message will show a peak in the magenta curve, followed
at a specified distance by a peak in the orange curve. The correct
locations of the two peaks are marked by small yellow ticks.
Unlike the alternating shorthand message tones, birdies will appear
with approximately equal amplitudes in the magenta and orange
curves.
6. For the convenience of temporary DXpeditions, a new JT65 feature
permits use of add-on DXCC prefixes that are not in the published
list of supported prefixes. Both stations in a QSO must enter the
required prefix (for example, PJ8 or FS) in a box on the
Setup->Options page. The effect will be to temporarily add the
entry to the table of supported prefixes.
7. The Setup->Options page has new entry fields labeled "Source RA"
and "Source DEC". You can enter the current right ascension and
declination of a radio source to be used for system calibration, or
perhaps a pulsar or a deep space probe that you wish to detect.
The program will display (on the Astronomical Data screen) the
current Azimuth and Elevation of the specified object at your
station. The source Azimuth and Elevation are also written every
second to the file azel.dat, in case you have automated tracking
capabilities that depend on this information.
8. For contest-style operations, the Setup->Options menu has an item
labeled "F4 sets Tx6". If this item is checked, when you hit F4 to
clear the To Radio box the program will turn Freeze OFF and set
the Tx message number to 6.
9. To facilitate the coming release of the full source code of WSJT
under the GNU General Public License, the proprietary soft-decision
Reed Solomon decoder has been removed from WSJT proper and made
into a separate executable module, KVASD.EXE. This change is
transparent to the user, and the full benefit of the soft-decision
decoder is still available. An open source hard-decision decoder
is also provided; it's what you get when you select the "Fast" JT65
decoding option.
10. In WSJT 5.8.6, if the value of "Freeze DF" (as displayed in the
Status Bar) differs from the sync tone frequency by more than
"Tol", shorthand decoding was suppressed even if Freeze was not
checked. This is a bug, and it has been fixed.
11. Earlier versions of WSJT had a bug that could cause the "Zap"
function to notch out a valid sync tone. Fixed.
12. The Help screens called up by F1 and Shift-F1 have been updated.
Be sure to read these screens: they contain many operational
conveniences that you may not have discovered!
13. At scrolling speed 5, the time labels and "minute separator" lines
were displayed erratically and the CPU load was excessive. Fixed.
14. Signal strength measurements above -20 dB were formerly compressed
and significantly underestimated. This has been fixed.
15. Decodings of the average of many properly synchronized transmissions
would sometimes go from "good" to "bad" after approximately 8-12
transmissions. This was a bug, and it has been fixed.
16. Several bugs in the FSK441 decoder have been fixed. Both
automatic decoding and mouse-picked decoding have been improved.
17. Changing WSJT modes now sets Auto to OFF, Tol to 400, and the Tx
message number to 1.
18. The generated audio for CW ID in FSK441 and JT6M modes has been
moved to 440 Hz, to avoid possible confusion with the other tones
used in these modes.
19. Readout of "Rx noise" on the main screen is now highlighted in red
if the level is outside the range -10 to +10 dB.
20. The Monitor button is no longer highlighted in green while you are
transmitting.
21. No attempt is made to decode if the Rx level is very low -- for
example, if your receiver is turned off.
22. If the Grid box does not contain a valid locator, readouts of
azimuth and distance are suppressed.
23. Keying of the audio tone to produce Morse code has been softened
to suppress key clicks.
24. Transmitted messages recorded in the file ALL.TXT are now
identified as to mode, and shorthand transmissions are noted as
such.
25. A number of other very minor bugs have been fixed.
Changes in WSJT 5.8.6
---------------------
1. Audio input and output has been modified in a way that accommodates
certain soundcards (e.g., SB Live!) that did not work correctly
with WSJT 5.8.3.
2. New item on Setup->Options menu to select whether GenStdMsgs forces
Tx message number to 1.
3. Status of all selectable items on Setup->Options menu is preserved
on program restart.
4. If a CQ is transmitted in JT65 mode, the Sked box is automatically
unckecked.
5. In v5.8.3, entering the same callsign and locator information in
MyCall and ToRadio/Grid could cause the program to freeze. Fixed.
6. If MyCall includes an extra prefix, as in 4X/ZL1RS, the standard JT65
messages should not include a grid locator. Fixed.
7. The "ms" parameter has been removed from the Soundcard status
readout at bottom left. Separate sample-rate factors are now
displayed for audio input and output, but only if "Enable
diagnostics" is checked on the Setup menu.
8. The SpecJT screen may now be made invisible by clicking on "X" in
the upper right corner. To restore it to visible status, click on
View->SpecJT on the main screen.
9. Decoded text lines in JT6M mode were sometimes too long, causing
end-of-line wrap-around. Fixed.
10. Some diagnostic messages printed to console window have been
removed.
11. The values of S, Sync, Clip, Zap and NB are now preserved when the
program is terminated and restarted.
12. Version 5.8.3 was unable to read back its own recorded wave files.
Fixed.
13. A programming error in the JT65 shorthand message decoder has been
fixed. Under certain conditions, this error could cause false
decodes of shorthand messages.
14. The logic of file saving commands Save Last, Save decoded, etc.,
has been corrected.
15. Wave files read from disk will now produce spectral plots on the
waterfall display if Monitor is OFF.
16. The CW ID feature has been implemented.
17. The mapping of signal levels to pixel colors and its dependence
on settings of Brightness and Contrast controls has been changed
so as to improve sensitivity to very weak signals.
18. In v5.8.3, changing Dsec would create erroneous results for the
displayed soundcard sample rate factor. Fixed.
19. Running in JT65 mode with Dsec>0 caused transmission errors
(including a gap in transmitted tones at t = 38-41 s), and the
resulting transmission was unreadable. Fixed.
20. Undesired resizing of main screen could occur when a long FSK441
message was transmitted. Fixed.
21. The "yellow line" displayed in the graphical area in JT6M mode
was computed incorrectly in version 5.8.3. Fixed.
22. When running at speeds 1-5, the waterfall spectrum may optionally
be "flattened" to remove rolloff at edges. To enable this
feature, check "Flatten spectra" on the SpecJT Options menu.
COMMENTS ON SOUND CARDS
-----------------------
In general, "high end" sound cards offer no advantages when used with
WSJT. Motherboard AC-97 compliant sound systems are cheap and work
well. If you do need to buy a sound card for use with WSJT, my advice
is to get a simple one. You do NOT need 8-channel surround-sound,
wavetable synthesis, special effects, etc. Those features are for
games and listening to music, and they will be wasted on WSJT.
Likewise, you do not need 24-bit A/D and D/A conversions.
Specifications having to do with signal/noise ratio are quite
irrelevant to use with WSJT, as you should never be operating in a
regime where A/D quantizing noise (or any other noise generated in the
sound card) contributes significantly to the system S/N.
If you have a choice, get a card that offers a *native* sampling rate
of 44100 or 11025 Hz, or both. (Unfortunately, it is often very
difficult to tell from the manufacturer's literature whether this
capability is present or not.) If native sampling at 11025 Hz is
available -- or if the manufacturer has at least provided a
well-designed resampling capability -- the soundcard sample-rate
factors (displayed by WSJT in the bottom left corner, if
"Setup->Enable diagnostics" is checked) should both be very close to
1.0000.
Changes in WSJT 5.8.3
---------------------
1. The Dsec parameter was not working properly in v5.8.1. Fixed.
2. CPU load at high waterfall speeds has been substantially reduced.
3. Saving cumulative file of decoded text is no longer optional. The
file name has been changed to ALL.TXT, to reflect use of this file
for transmitted as well as decoded text.
4. Logic for green bar illustrating region searched for sync tones has
been corrected.
5. Bug producing index error in "plot_yellow" is fixed.
6. Bug causing crash in CW mode if TRPeriod > 60 s is fixed.
7. Tabular listing of Audio devices has been clarified.
8. Name at top of waterfall screen has been changed to "SpecJT" so
that its icon can be distinguished from that of main screen.
9. VOX control of T/R sequencing is now permitted by setting the COM
port to 0.
10. Exit from program with the "To Radio" box empty caused error
message and substitution of default parameters on restart. Fixed.
11. Default FSK441 message #5 for EU has been changed to "73 MyCall"
(which I am told conforms with standard EU practice).
12. Lower case letters are now acceptable in entries on Setup->Options
screen, and will be translated appropriately to upper case in
transmitted messages.
13. The file AZEL.DAT has been moved to the WSJT6 installation
directory.
14. The "Sh Msg" box was always checked when entering FSK441 mode. It
now remembers its state if you had unchecked it.
15. Keyboard shortcuts have been implemented for most on-screen
controls. Use F1 to see a full listing.
16. "Gen Std Msgs" now sets the Tx message to #1 in all WSJT modes.
17. Self-echo doppler value has been replaced by "Dgrd" in the
astronomical data displayed on the main screen.
18. The audio stream has been trimmed by 0.5 s at the start of FSK441
and JT6M Rx sequences, to prevent possibly copying one's own Tx
signal. (Is this enough?)
19. Two header parameters in wave files recorded by WSJT have been
corrected so that the files can be read correctly by Windows Sound
Recorder.
20. Four-digit grid locators no longer produce incorrect azimuth
headings.
21. Logic error in the waterfall's horizontal scrolling mode fixed.
23. The active Tx message box is now highlighted during a
transmission, as in WSJT 4.x.
24. Green ticks marking range of JT65 tone frequencies and red ticks
marking shorthand tones may optionally be displayed only if Freeze
is checked. (Select on waterfall screen's Options menu.)
25. "Tool-tip" readout of full entry in CALL3.TXT is now provided
after Lookup, if mouse pointer hovers over the ToRadio box.
26. Parameter RDsec was removed from the screen, as it is not
implemented.
27. Some additional diagnostic information is now displayed. A
parameter "ms" following the "Soundcard x.xxxx" readout is a
measure of the maximum time between successive servicing of the
audio callback routine. The nominal value is about 186 ms, but
somewhat larger values are normal owing to granularity of the
Windows system clock. Values larger than 330 ms cause a warning
message to appear in the console window. Large values of this
parameter may be related to audio input problems (see below).
28. The latest version of DL8EBW's CALL3.TXT database is included with
the distribution. It will be installed only if there is no file
named CALL3.TXT already in your WSJT6 installation directory.
KNOWN PROBLEMS
--------------
1. Some fraction of WSJT 5.8.1 users -- perhaps 5-10%, it is hard for
me to judge -- have had problems with erratic audio input. I am
having difficulty tracing the problem because I have not been able
to reproduce it on any computer to which I have access. Typical
symptoms are that after startup WSJT 5.8.1 runs normally in Monitor
mode for a minute or so, but then the reported audio level jumps to
a much higher value and perhaps fluctuates wildly.
Two users have switched todifferent sound cards and made the
problem go away. Several others have discovered that if they first
start WSJT4 and leave it running (in Monitor mode, I believe), and
then start WSJT 5.8.1, the new program behaves properly. One user
corrected the problem by turning off an "AGC" feature on his sound
card. Apparently most of the newer SoundBlaster cards have this
AGC feature, and it is turned ON by default. I am told that it can
be turned OFF by using the supplied utility CTMIX32.EXE.
I do not yet understand the cause of the erratic audio problem. It
is possible that it has been fixed in v5.8.3, as several minor
changes have been made to the audio input routines; but I think
this is unlikely.
If you had this problem at your station and have now solved it,
please let me know what you did! If you still have problems when
running version 5.8.3, let me know about that as well.
2. I do not yet have a good definition of the "minimum computer"
required to run WSJT6. Several people have told me that they are
using the program successfully on 300-500 MHz machines. Those with
computers slower than about 600 MHz will do best to avoid the
higher waterfall speeds and not run many other programs while using
WSJT.
Beta Release 5.8.1
------------------
Beta release 5.8.1 is an entirely new program, dsesigned to preserve
the features and the "look and feel" of version 4.9.8, but also to add
many new features and do so in a way that will make for easier for
program maintenance and future development. After a period of beta
testing, the program will become known as WSJT 6.0. I will refer to
it here as WSJT6.
Many features of WSJT6 will be familiar to present users of WSJT4.x.
However, the user interface and other real-time portions of the
program have been entirely re-written, so you may find a few things
that look different or work differently than before.
WSJT6 is a multi-threaded program. This architecture permits much
better timing control and much better sharing of the CPU among the
program's many tasks. A real-time waterfall is provided, optimized
for each of the WSJT modes. You can measure and set the Rx gain in
real time. You can decode FSK441 pings immediately after hearing
them.
The decoders for JT65 and JT6M are essentially the same as those in
recent versions of the program. (I have many plans for enhancements
to the decoders, but these must wait for future updates.) The FSK441
decoder has intentionally reverted back to approximately version
3.8.1, because it has been shown that recent versions did not perform
quite as well.
WSJT 5.8 is a stable release. Extensive tests by a small group of
early beta testers have already shown that it works well. However, it
contains many thousands of lines of new code, and most likely that
code has some bugs. Nevertheless, I think you will find many
operational advantages to using it. Over the past 2.5 months, all of
my own MS and EME QSOs have been made with the new version.
If you decide to participate in the beta testing period, please accept
the responsibility of reporting any bugs that you find, as well as
telling me of features you would still like to see. I would
appreciate hearing about new features that you like, as well.
PRELIMINARY INSTRUCTIONS AND COMMENTS
-------------------------------------
1. I suggest installing WSJT6 to a new directory such as C:\Program
Files\WSJT6. After installation you will probably want to copy
your version of the callsign database, CALL3.TXT, into the new
WSJT6 directory, replacing the one that is supplied.
2. When you start the program you should get three windows on your
screen. One has a black background and I will call it the "console
window"; it is mainly used for debugging messages. You can
minimize it and generally ignore it. You should, however, look
there for messages if the program crashes (see also items 9 and
11, below). The other two windows are a Spectran-like waterfall
and the more-or-less familiar WSJT window. It is no longer
necessary or desirable to run Spectran simultaneously with WSJT.
3. FSK441, JT65, and JT6M are all present and functional. I have made
many QSOs with FSK441 and JT65, so I know they are working well.
JT6M has been tested somewhat less, but I have seen no problems as
yet. EME Echo mode and the CWID feature are not yet implemented.
4. To start the real-time spectral display, click Monitor. Normally
you can leave Monitor on all the time.
5. There are two ways to set the Rx Audio gain. You can call up the
Windows mixer as before, using the "Rx Volume Control" item on the
Options menu. There is also a digital gain control near the
bottom right of the waterfall screen. You should aim for around 0
dB, as before -- but with 16-bit audio sampling it is no longer
very critical. Use the "S-meter" at the lower right of the
waterfall display, or the familiar box labeled "Rx noise" at
bottom center of the main screen.
6. You should be able to make FSK441, JT65, and JT6M QSOs more or
less as usual. In FSK441 and JT6M you will want to run the
spectral display at speed "H1" or "H2" (speed is selected at the
top of the waterfall screen). (The "H" means horizontal
scrolling.) Scrolling speeds "5" and "H2" use a lot of CPU time,
so you may want to avoid them unless your computer is pretty fast.
I generally use speed "1" or "2" for JT65 and "H1" for FSK441 and
JT6M.
7. When running FSK441 in the horizontal scrolling mode, the spectral
display shows current data in the top half and the previous Rx
sequence in the bottom half. The most recently decoded sequence
is shown also on the main screen, as in version 4.x.
8. You can decode FSK441 pings right away by clicking on any of the
2-dimensional spectral displays, or the accompanying green lines.
You can click on the top half, the bottom half, or in the main
screen's graphical area.
9. If you have more than one sound card, you can select the desired
one. Look at the startup messages in the console window. You
should see a list of the available Audio devices and information
about which one has been selected. If you wish to change the
selection, enter the desired device numbers on the Setup->Options
screen, then terminate and restart the program.
10. If your display has resolution 1024 x 768 or less, you may prefer
to resize the waterfall window so that only its top portion
remains visible. The two main WSJT windows may then be kept
visible without overlapping.
11. Some program crashes can kill the console window so that you can't
read the error messages. If this happens, and if the crash is
repeatable, open a Windows Command-Prompt window; CD to your WSJT6
installation directory, and start the program from there by typing
"WSJT6". With this startup procedure, any subsequent post-mortems
will remain visible. Please report any such messages to me!
12. You may find decoding to be slightly slower than with v4.9.x. I
have not yet spent any time optimizing the new code for speed; it
will get faster when I turn attention to that task. If you have
an older computer you may wish to check the menu item
"Setup->Accelerated decoding", which will suspend updating the
waterfall during the decoding process.
13. Be sure to look at the screens called up by function keys F1 and
Shift-F1. These screens are also available from the Help menu.
They list some useful keyboard and mouse commands that you might
otherwise overlook.
14. Be sure to explore all the menus and on-screen controls, and try
out the commands listed on the help screens. Until I can find
time to write a new manual, this is the best way to learn about
some of the new features.
15. In JT65 mode, a horizontal green line on the frequency scale shows
the range of frequencies that will be searched for a sync tone.
You can set the "Freeze DF" value by clicking on the main screen's
red curve (as in WSJT 4.x) or by clicking on the waterfall with
the shift key held down. If "Freeze" is checked, vertical green
ticks will mark the selected sync-tone frequency and the
corresponding frequency of the highest data tone. Red tick marks
denote the frequencies of the RO, RRR, and 73 shorthand messages.
16. WSJT6 can read and process WAV files produced by earlier versions.
The converse is not true, however, because earlier versions of
WSJT are not equipped to read the 16-bit data files produced by
WSJT6.
17. When you click "Log QSO," a line with date, time, HisCall,
HisGrid, frequency, and mode is added to the file WSJT.LOG in the
installation directory.
18. Every second, a short file named "c:\azel.dat" is updated with
time, moon and sun coordinates, frequency, doppler, and doppler
rate information. This file could be used by other software to
make your antenna track or your radio follow doppler changes.
19. In the lower left corner of the main screen you will see a message
of the form "Soundcard: x.xxxx", where x.xxxx is a number close to
1.0000. This number is the ratio of the soundcard's measured
sampling frequency to the nominal value, 11025 Hz. The displayed
value should stabilize after the program has been running for a
minute or so. If you see values less than about 0.9990 or greater
than 1.0010, please let me know about it and tell me what kind of
computer and sound card you are using.
20. Callsigns for Swaziland (prefix 3DA0) can now be used in standard
JT65 messages, and they will provide the full "deep search"
sensitivity.
21. The box labeled "NB" enables a software noise blanker. If your
receiver already has a good noise blanker, this may be of little
use; if it does not, you may find this one better than nothing.
It can be helpful when short, impulsive noise spikes are present.
22. The "QRN" parameter of older WSJT versions has been combined with
the "Clip" parameter. In FSK441 mode, Clip=0 corresponds to the
old QRN=5. If you want more FSK441 immunity to summertime QRN,
increase Clip above 0 just as you would have increased QRN above
5.
23. The "B" and "C" submodes of FSK441 have not been implemented. As
far as I could tell, they were little used.
Let me call your attention to the online WSJT Forums hosted by DK5YA
at www.vhfdx.de/cgi-bin/yabb/YaBB.pl. If you provide information and
post questions about WSJT 5.8 there, it will help others as well as
yourself -- and may help to reduce the load on my email inbox.
I do, of course, want to hear from you directly if you have found a
problem with the new program version or suggestions for its
improvement.
Changes in Version 4.9.8
------------------------
Version 4.9.8 is a minor maintenance release. The changes are:
1. Bug in JT65 decoder could (rarely) cause a correct decoding by the
Reed-Solomon decoder to be "overruled" by an incorrect decoding
from the Deep Search decoder. Fixed.
2. Bug in JT65 Reed-Solomon decoder could cause program to crash under
certain rare conditions. Fixed.
3. The standard "CQ" message generated for a callsign having an extra
prefix or suffix should not include a grid locator. Fixed.
4. Automatically generated CW messages for stations with callsigns longer
than 4 characters were improperly truncated. Fixed.
5. Bug in JT65 decoder could occasionally cause one or two extra
letters to be appended to a correctly decoded callsign. Fixed.
6. Grid locator entered in "Report" box in FSK441 mode (as used by
some in North American meteor scatter contest) would cause a crash
on program restart. Fixed.
Changes in Version 4.9.7
------------------------
1. The only change in version 4.9.7 is to add KC4 to the list of supported
DXCC prefixes.
Changes in Version 4.9.6
------------------------
1. WSJT 4.9.5 fails to decode some files that have relatively high S/N
and good Sync level. This is a bug, and has been fixed. For this
reason alone, you should definitely upgrade to Version 4.9.6.
2. New optional message formats are provided for conveying and
responding to signal reports.
It has been permissible for some time to send, for example,
VK7MO K1JT -24
K1JT VK7MO R-27
(The number after the minus sign must have two digits and must be in
the range -01 to -30.)
I plan to implement a quick way of copying the measured strength
of a decoded transmission into TX message #2, when desired. This
is not yet done in v4.9.6, however. You must edit the TX messages
by hand if you use these formats.
Enhancements in version 4.9.6 now allow you to send messages like
the ones listed below. Both stations will need to be running
v4.9.6 in order for these to work:
VK7MO K1JT RO
VK7MO K1JT RRR
VK7MO K1JT 73
3. Decoding by the deep search algorithm has been extended so as to
include messages of the types discussed in item 2.
Changes in Version 4.9.5
------------------------
1. Full support for long callsigns like ZA/PA2CHR and G4ABC/P is now
provided. When using such a callsign prefix or suffix, do not
include a grid locator in your transmitted message. Note that
4.9.5 and 4.9.2 do not handle prefixes in the same way; they are
not compatible. To get the benefit of the expanded capability,
both stations (TX and RX) must use 4.9.5. The correct message
format is "K1JT V5/ZS5Y" or "V5/ZS5Y K1JT". The extended callsign
must be present in CALL3.TXT or in "To Radio" for the deep-search
decoder to be effective.
2. If you double-click on a callsign in the decoded text window, and if
the word preceding the callsign is "CQ", then TX message #1 will be
selected after the messages are updated. Otherwise, TX message #2
will be selected.
3. So that you will be aware of what is happening, the background
color in the TX message box turns red whenever a message you have
entered is "non-standard" and will be sent as 13 characters of
plain text.
4. Items related to decoding have been removed from the Setup |
Options screen and replaced by a new menu labeled Decoding. Here
you may now select "No shorthands" for FSK441 and several options
for JT65 decoding.
5. In case you are upgrading directly from v4.9.0 or earlier to v4.9.5,
a callsign database file has been included as CALL3A.TXT. If you do
not already have a file CALL3.TXT, you should rename the supplied
file to CALL3.TXT. Otherwise, you will probably want to ignore
the supplied file, since you will have made additions to your own
copy.
6. The frequency of program crashes (for example, after a long period
of monitoring) is much reduced, possibly to zero.
Please, if you encounter a received wave file that reproducibly causes
WSJT to crash, send it to me.
Changes in Version 4.9.2
------------------------
1. In CW mode you can now set the desired T/R period by using the text
box provided. This feature did not work properly in v4.9.1.
2. Under some conditions using the "Add" button to edit information in
the file CALL3.TXT would cause a program crash with the message
"Run-time Error #53". Fixed.
3. Using the double-mouse-click on a callsign in the decoded text
window will now set the active Tx Message to Tx2. I believe this
will be most commonly what is desired, and will be an added
convenience for random JT65 operation.
4. The "Sked" box remained visible on the EME Echo screen, covering
part of the RIT box. Fixed.
5. The program generates two numbers to characterize its level of
confidence in decoded messages. In version 4.9.1, these numbers
appeared at the end of each decoded text line. They are not
displayed in version 4.9.2, but in the next version I will
probably display them if you have checked the "Aggressive decoding"
box. The first number is 0 or 1 according to whether the
soft-decision Reed Solomon decoder has failed or succeeded. The
second number represents a confidence level on a 0-10 scale for
messages decoded using the "deep search" algorithm. Anything under
3 is questionable; messages rated 6 and above are unlikely to be
wrong, unless you are processing "garbage" data containing strong
birdies, QRN, etc. In that case, you are on your own.
6. A bug was introduced when implementing the "Aggressive decoding"
check box. This bug caused a stray "OOO" flag to be sometimes
displayed even when no signal was present and synchronization had
not been achieved. Fixed.
Changes in Version 4.9.1
------------------------
1. A programming error in version 4.9.0 prevented the "deep search"
portion of the JT65 decoder from detecting some messages that include
the "OOO" signal report. The bug has been fixed, and consequently the
extra 4 dB of sensitivity will become available for those messages.
2. The callsign database, a file named CALL2.TXT in version 4.9.0, has
been converted to a comma-delimited format and is now named CALL3.TXT.
As has been true in the past, you should maintain your own copy of
this file according to your own needs. New calls may be added to the
file using the "Add" button of WSJT, and you can edit the file
directly with the Windows NotePad program. I apologize for the fact
that if you have already edited CALL2.TXT extensively, you will need
to do so again. The good news is that the programs WSJT, MoonSked (by
GM4JJJ) and Tracker (by W7GJ) will now use the same database file,
CALL3.TXT.
3. Two new JT65 check boxes have been made available to the user: one
labeled "Sked", located on the main screen, and one labeled "Aggressive
decoding" on the Setup | Options screen. Check "Sked" to signify that
you are trying to work a known station; the deep search decoder will
then look only for your own call and the one displayed in the "To
Radio" box. Check "Aggressive search" if you want to see all messages
found by the deep-search decoder, even if the confidence level is
moderately low. Leave this box unchecked if you prefer to see only
decoded messages that have been assigned a relatively high confidence.
4. The duration of T/R sequences in CW mode defaults to 60 s if the
Band is 50 MHz, 150 s if 432 MHz, and 120 s otherwise. However, an
on-screen box now allows you to override the defaults and set any
desired T/R period (in seconds).
Changes in Version 4.9.0
------------------------
On the outside WSJT version 4.9.0 looks nearly the same as its recent
predecessors. A "CW" entry now appears on the Mode menu. This is
presently a "transmit only" mode: it sends standard EME-style messages
at 15 WPM, by keying an 800 Hz audio tone, and it takes care of the
timing and T/R switching for you. Receiving is left up to you, the
operator. For me, this combination makes CW EME QSOs relaxing and
enjoyable. Presently the program uses 2.5 minute sequences if you are
on 432 MHz, 2 minutes on 144 MHz, and 1 minute on 50 MHz. (If you
want to run with 1-minute sequences on 144, set the band indicator to
50 MHz.)
Double-clicking on a callsign in either one of the decoded text
windows will cause that callsign to be copied into the "To Radio" box.
The call will then be looked up in the database and will be inserted
appropriately into the transmit message boxes Tx1 and Tx2. This
feature is designed to facilitate random JT65 operation by making it
easy to call a station you have just copied calling CQ, or responding
to your CQ.
The most significant program enhancements are those made to the JT65
decoder. It has been transformed into a multi-layered procedure that
takes better advantage of the structured nature of JT65 messages and
the substantial computing capability that most WSJT users have in
their hamshacks.
In version 4.9.0, if the initial JT65 decoding effort fails then
deeper searches are attempted using an entirely different approach.
The result is a net gain of about 4 dB over a wide range of
circumstances. My JT65 digital simulator, which has accurately
predicted the performance of previous versions of the software,
correctly decodes about 50% of simulated Rx files with the v4.7.0
decoder at a signal level of -24 dB. With the v4.9.0 decoder, it
correctly decodes more than half of the simulated data files at -28
dB. This very substantial improvement means that JT65's
message-averaging facility will be needed much less frequently than
with earlier versions of WSJT. Most of the time, if the transmission
synchronizes properly, it will also decode properly.
You will get better performance from the new JT65 decoder if you
understand a few things about how it works. The following is a very
brief description; more complete technical details will be forthcoming
when I find time to write it all down.
JT65 is capable of transmitting and receiving 2^72 (about 5 x 10^21)
distinct user messages. Instead of sending the minimum number of 72
information bits needed to to convey any one of those distinct
messages, the program actually sends 63 six-bit "symbols" for a total
of 378 bits in each transmission. The 302 extra bits comprise the
powerful forward error correction (FEC) capability of the JT65 mode,
allowing the system to function reliably with signals far below the
audible threshold.
One of the first tasks of the JT65 decoder is to measure the signal
level at each of the 64 data-tone frequencies during each of the 63
data intervals in a transmission. The program must then decide which
one of the possible 2^72 messages was most likely the one sent. This
procedure is necessarily probabilistic in nature. The best decoder
will go as far down into the noise as possible, but it must also know
when to give up so that it produces few false decodes.
The total of 2^72 distinct messages is far too many to permit each one
to be tested individually against the received signal. However, an
important characteristic of the Reed-Solomon FEC code used in JT65 is
that well-defined mathematical algorithms can be used to direct the
decoder toward the most likely candidate messages, based on the
available signal information. A mathematical inversion of the code is
made possible by the organization of the redundant information
contained in the 306 extra bits.
The new JT65 decoder goes far beyond the capabilities of normal
Reed-Solomon decoders. If the standard decoding procedure fails to
produce a high-confidence solution, the program proceeds to search
explicitly for each one of a number of messages that it considers
likely or plausible on other grounds.
Nearly 2^28 (over 250 million) different callsigns can be accommodated
in each of the two callsign fields of a JT65 message. Once again,
this is far too many to permit an exhaustive search for them all.
Consequently, the "deep search decoder" takes the callsigns listed in
the file CALL2.TXT (located in the user's WSJT directory) as being the
most likely alternatives in the message's second field. A correlation
algorithm is then applied to find out if one of these calls and its
associated grid locator are present, combined with either "CQ" or the
receiving station's callsign in the first field. High-confidence
matching of this kind can be accomplished down to about -28 dB on the
WSJT scale, in a single transmission, with a very low error rate.
The bottom line is that for any arbitrary callsign the new JT65
decoder performs at least as well as the one in WSJT version 4.7.0.
Message averaging works just as it did before, and if you are
listening in to a "third party" QSO between two other stations, the
sensitivity will be the same as in version 4.7.0. However, if a
station that is listed in the file CALL2.TXT is calling CQ or is
calling you, your sensitivity will be about 4 dB better on average.
Please note that the decoder is given no information whatsoever about
what station you may be trying to work. Its heart is "as pure as the
driven snow," even if you are working a sked. However, the decoder
does presume that the callsign of the transmitting station is more
likely to be one listed in CALL2.TXT than some other callsign
constructed at random.
The program always attempts to decode a purely arbitrary message
first. Failing that, it will look more deeply in the noise for the
presence of a message that includes the callsign of a station listed
in the database file.
It is no accident that the algorithm just described bears close
resemblance to the thought processes (conscious and otherwise) that we
use to copy very weak CW by ear. Familiar combinations like CQ and
one's own callsign are always easier to dig out of the noise than
random combinations of characters. Callsigns that we have seen or
heard before are more easily recognized than arbitrary calls generated
at random. The new JT65 decoder behaves similarly, except that it
is kept fully in the dark about who you are trying to work.
All decoders make mistakes, and this one is no exception. Just like a
human copying CW, the JT65 decoder has a "grey area" in which it finds
a solution but may have only moderate confidence in it. In such cases
the decoder appends a "?" to the decoded text, and the operator must
make the final decision as to whether the decoding is correct. Be
aware that because of the mathematical message structure, incorrect
decodings will not just differ from the correct one in a few
characters; more likely, they will exhibit a whole incorrect callsign.
As you gain experience in recognizing the graphical and numerical
indications of proper message synchronization and the effects of
"birdies" and other interference, you will become adept at making
these decisions when necessary. With added on-the-air experience I will
probably be able top reduce the decoder's error rate, as well.
A final note: the file CALL2.TXT replaces the file CALLSIGN.TXT used
by earlier versions of WSJT. The format has been changed to permit
extended callsigns such as those sometimes used by DXpeditions, for
example ZA/PA2CHR. The name of the database file has been changed so
as not to "break" an earlier version of WSJT that you may wish to keep
available. Full support for extended callsigns (i.e., calls with an
extra prefix or suffix) is planned for a future version of WSJT.
Changes in Version 4.7.0
------------------------
1. New feature: WSJT can now be used simultaneously with Spectran on
the same computer. You can start Spectran by selecting "Use Spectran
for input" on the Setup menu. This feature also allows the user to
select the sound card to be used for input.
2. Bug fix: in some circumstances, switching from a JT65 long-format
message to a shorthand message did not work properly. Fixed.
3. Bug fix: for operators in the southern hemisphere and longitudes
more than 90 degrees east or west, the wrong "Hot spot" was sometimes
identified as the best direction for sporadic meteors. Fixed.
Changes in Version 4.6.1
------------------------
1. Bug fix: I mistakenly shifted the RX data by 2 seconds, rather
than the intended 1 s, when changing the DT range. Therefore in
v4.6.0 the actual DT range is not -1 to +5 s as stated, but rather 0
to +6 s; moreover, the displayed values of DT are too small by 1.0 s.
This has been fixed.
2. New feature: thanks to Akira, JM1SZY, I learned that occasionally a
file (or an average of several files) will decode better with the AFC
feature turned off. Consequently I have added a checkbox that must be
ticked to activate AFC in the JT65 modes. If you can trust the
frequency stability of the signal you are receiving, and especially if
you are trying to receive a signal at -27 dB or weaker, leaving this
box unchecked may yield a slight improvement in decoding. In most
cases, especially at 144 MHz and above, I recommend leaving the AFC
turned ON.
3. Thanks to Chris, GW4DGU, for pointing out that the Gx series of
prefixes is no longer legal for reciprocal license operating in the
countries of the UK. The valid prefix series for such operation is
now the M-series, i.e., M MD MI MJ MM MU MW. I have changed the
prefix table accordingly.
Version 4.6
-----------
This is the first full release of WSJT since version 3.0. New users
can install Version 4.6 directly, without upgrading from a previous
installation. Of course, you can also upgrade from an earlier version
in the usual way. All download files can be found on the WSJT home
page, http://pulsar.princeton.edu/~joe/K1JT.
The new release includes an entirely new "WSJT 4.6 User's Guide."
This document is about one third the length of the former "User's
Guide and Reference Manual," but contains nearly everything you need
to know to use the program. A copy of the new Guide is included in
the version 4.6 distribution files. You can also download it directly
from http://pulsar.princeton.edu/~joe/K1JT/WSJT_User_460.pdf. Even if
you are an experienced WSJT user, you should definitely print and read
this document.
New features in WSJT Version 4.6 include the following:
1. Improved automatic frequency control in JT65 modes. If you have
lost JT65 QSOs because of unstable oscillators, this is for you.
2. The acceptable range for DT in JT65 mode is now -1 to +5 s. This
range is a better fit for EME communication than the former -2 to +4
s. It will allow for somewhat greater clock errors before
inter-station synchronization fails on an EME path.
Note to experienced users: this means that the plotting scale for the
"blue curve" now runs from -1 to +5 s. EME signals should normally
produce a blue peak near the center of the plot area.
3. When the blue window displaying moon coordinates has been toggled
to display coordinates for the DX station as well as the home station,
it now displays MaxNR in place of SD. MaxNR is the maximum path
non-reciprocity in dB. This effect arises from the combination of
spatial polarization shift plus Faraday rotation; it is what causes
"one way propagation" between stations that use fixed linear
polarization.
4. A facility for generating the file ID.WAV for station identification
is now built into WSJT.
5. The "Save Decoded" menu item now saves files with decoded shorthand
messages as well as normal messages.
6. JT65 has a new shorthand message "ATT" (for "Attention!"). It is
intended as an aid to help two stations find each other by determining
the correct DF.
7. Visual aids for evaluating JT65 shorthand messages "by eye" are
provided if you click on the sync-tone frequency in the Big Spectrum
display.
8. For DXpeditions: a country prefix preceded by "/" may be
substituted for the grid locator in a type 1 JT65 message.
9. Alternatively, a signal report of the form "-NN" or "R-NN" may be
substituted for the grid locator in a type 1 JT65 message. For
example, -24 might indicate that signals were being received at -24
dB. The minus sign is required, and NN must lie between 01 and 30.
10. The receiver noise level reported by Measure mode (the level of the
"green line") has been increased by 2 dB to be consistent with levels
reported by the other operating modes.
Changes in Version 4.5.1
------------------------
Bug fixes:
1. JT6M did not transmit properly in version 4.5.0 because the program
failed to switch its wavefile generator into JT6M mode. Fixed.
2. WSJT consumed a large fraction of CPU time in JT65 mode, even when
the program was supposedly doing nothing. Fixed.
3. Monitoring for long periods in JT65 mode would occasionally produce
a Fortran "output conversion error". Fixed.
4. Clicking the "Add" button with nothing in the Grid box would cause
a program crash. Fixed.
Enhancements:
1. In the FSK441 modes, messages longer than 3 nonblank characters and
starting with R26, R27, RRR, or 73 are no longer transmitted as
shorthand messages.
2. Onscreen labels now indicate active status of the "Save Decoded",
"Save All", and "Save text in File DECODED.CUM" features.
3. Small improvements have been made in the decoding of shorthand
messages in modes FSK441B and C.
4. Alphabetic characters in message templates (on the Setup | Options
screen) are now case-insensitive.
Principal New Features in WSJT Version 4.5
------------------------------------------
1. The JT65 modes employ an entirely new decoding algorithm that uses
"soft decisions" to recover the transmitted message. The message
format and Reed-Solomon encoding are unchanged, so the JT65A, B, and C
modes are fully compatible with earlier versions. However, the new
decoder is more sensitive by slightly more than 1 dB. It is based on
software licensed from CodeVector Technologies, LLC, and protected
under United States Patent 6,634,007. As usual, however, I am making
WSJT freely available for amateur radio use.
Changes to the JT65 modes are "under the hood," and except for the
improved performance you will find them mostly invisible. The new
decoder can be somewhat slower than the one in v4.3.4, depending on
details of the received data.
2. Like JT65, FSK441 now provides three submodes. FSK441A is
identical to the "classical" FSK441. The two new modes, FSK441B and
FSK441C, use the same 4-tone frequency shift keying at 441 baud.
However, they use forward error correction (FEC) on a
character-by-character basis, to improve message reliability. They
also provide shorthand messages which are more robust than the
single-tone messages of traditional FSK441. Cross-mode communication
will not work: a transmission in FSK441B must be received in FSK441B,
etc.
FEC information in FSK441B and FSK441C is conveyed by sending
additional channel symbols (tones) for each character, using special
codes designed to optimize the error rate and sensitivity with very
short pings. The additional symbols are redundant when the S/N is
high, but they allow recovery from transmission errors when the S/N is
low.
FSK441A, which provides no redundancy, transmits 3 symbols per
character. Modes B and C use 4 and 7 symbols per character,
respectively. The raw throughput of user information is summarized
in the following table:
FSK441A FSK441B FSK441C
----------------------------------------------------------------
Sequential tones per character 3 4 7
User data rate, characters/second 147 110 63
Time for a 12-character message, ms 82 109 190
The shorthand messages in FSK441B and FSK441C use alternating tones at
two specific frequencies, as follows:
Shorthand Low tone High tone
message (Hz) (Hz)
------------------------------
R26 861 1206
R27 861 1550
RRR 861 1895
73 861 2239
Tests with my digital simulator show that shorthand messages in
FSK441B and FSK441C are several dB more sensitive than the ST messages
of FSK441A. At the same time they give a far lower rate of false
positives.
With multi-tone messages the sensitivities of the three submodes are
nearly the same, but they have different trade-offs. Mode A is 25
percent faster than mode B, but mode B is more accurate and will
produce much less on-screen "gibberish". Mode C is about half the
speed of mode A but has still stronger FEC code. Parameters of the B
and C modes were selected in the expectation that FSK441B might become
the mode of choice for meteor scatter work on 144 MHz (and possibly
also 222 MHz), while FSK441C will likely prove best at 50 MHz where
the pings are longer. These suppositions need to be tested, of
course.
Experienced WSJT users should have no difficulty making the new modes
work. Just select the desired mode from the Mode menu (or use the
appropriate hot-key combination), and away you go.
Other Changes in Version 4.5.0
------------------------------
1. Bug fix: In JT65 mode, if you sent 73s and then started a QSO with
a new station, the program would sometimes continue sending the 73
message even though TX message #1 had been checked. This has been
fixed.
2. Performance enhancement: Shorthand messages in JT65 were sometimes
suppressed because of an apparent low-value Sync detection that
produced no decoded message. This has been fixed; there is no longer
any need to set your Sync threshold to a higher value when you are
expecting to receive a shorthand message.
3. The JT65 "Filter" function has been removed. It was confusing to
some, and anyway was generally deemed of little value. The new
decoder provides a much better solution.
4. The "suggested report" has been deleted from FSK441 decoded text
lines. It is replaced by S/N, the measured signal-to-noise ratio in
dB. Note that the familiar "dB" measurement of (S+N)/N is still
available, as well.
5. Finer adjustment intervals are provided for "S", the FSK441 ping
detection limit. As in earlier version, these numbers refer to
(S+N)/N. In contrast, the "Single Tone" or "Shorthand" detection
limits refer to S/N, a more useful parameter at very low signal
levels. (See below for more details on signal to noise ratios, if
interested.)
6. A button labeled "Add" just below the grid locator box will cause
the displayed callsign and grid to be entered into the CALLSIGN.TXT
database.
7. A date and time stamp is now added to the DECODED.CUM file at
program startup or when you first enable writing to this file.
Request to Users
----------------
As usual, I will appreciate hearing from users about the new features
in WSJT. Let me know, of course, if you find bugs or other problems
in the program. In particular, let me know of your experiences with
FSK441B and FSK441C. Remember, my guess is that FSK441B should work very
well on 2 meters, while FSK441C may work best on 6 meters. After
you have gained some experience with FSK441C on 6 meters, I would be
interested to know whether you think JT6M should be retired. In North
America, at least, I do not think it is being used very much.
Why use both S/N and (S+N)/N ?
------------------------------
WSJT has traditionally measured the level of FSK441 signals as the
ratio (signal plus noise)/(noise) = (S+N/N), in dB. This quantity is
approximately what S-meters try to measure; it has the advantage that
it goes to zero when there is no signal, while at high signal levels
it increases as you would expect, in proportion to signal strength.
At low signal levels, however, the numbers for (S+N)/N in dB behave in
a way that may be counter-intuitive. When WSJT reports that a meteor
ping had strength 3 dB, it means that signal plus noise was 3 dB
higher than noise alone. That means that signal and noise were equal
in power, so the corresponding value of S/N must be 0 dB. If the same
signal had been transmitted with half the power, it would have had S/N
= -3 dB, and (S+N)/N would have been 10*log(0.5+1.0) = 1.76 dB. Yes,
cutting the TX power in half would only reduce the ping level from
3.0 dB to 1.76 dB! That's why, for many purposes, S/N is a more
useful number -- and why I am now listing both numbers in FSK441
decoded text lines.
The table below will allow you to convert easily between S/N and
(S+N)/N, both as numerical ratios and as dB.
S/N S/N (S+N)/N (S+N)/N
(dB) (dB)
----------------------------------------
10.0 10.000 11.000 10.41
9.0 7.943 8.943 9.51
8.0 6.310 7.310 8.64
7.0 5.012 6.012 7.79
6.0 3.981 4.981 6.97
5.0 3.162 4.162 6.19
4.0 2.512 3.512 5.46
3.0 1.995 2.995 4.76
2.0 1.585 2.585 4.12
1.0 1.259 2.259 3.54
0.0 1.000 2.000 3.01
-1.0 0.794 1.794 2.54
-2.0 0.631 1.631 2.12
-3.0 0.501 1.501 1.76
-4.0 0.398 1.398 1.46
-5.0 0.316 1.316 1.19
-6.0 0.251 1.251 0.97
-7.0 0.200 1.200 0.79
-8.0 0.158 1.158 0.64
-9.0 0.126 1.126 0.51
-10.0 0.100 1.100 0.41
Beta Release 4.3.4
------------------
Beta Release 4.3.4 of WSJT is now available for free download at the
WSJT home page, http://pulsar.princeton.edu/~joe/K1JT. The principal
change from version 4.2.1 is to offer three JT65 submodes. The
submodes differ in tone spacing and total bandwidth as follows:
Mode Spacing Total BW
-------------------------
JT65A 2.7 Hz 177.6 Hz
JT65B 5.4 355.3
JT65C 10.8 710.6
Note that JT65A is identical to the original JT65. If you want to
work people who have not yet upgraded to v4.3.4, be sure to select
mode JT65A. Otherwise, be sure to use the same mode that your QSO
partner is using. Cross-mode contacts will not work.
JT65B should be nearly as sensitive as JT65A, and it will be twice as
forgiving of frequency instabilities. On balance, with existing
"stock" radios, JT65B will probably be better than JT65A. JT65C is
less sensitive by a small amount, perhaps 1 dB, but will be even more
lenient on stability issues. By all means experiment with the
different submodes, and be sure to let me know your conclusions about
them!
I am presently inclined to recommend that JT65B should become the
"standard" JT65 mode. If this tentative conclusion holds up, future
versions of the program may no longer support the A and C modes.
Other changes from version 4.2.1 include the following:
1. Further improvements have been made to the JT65 decoding
algorithm. These improvements apply to all three submodes. Some
wave files that would not decode with v4.2.1 now decode properly,
especially in averages over several minutes.
2. The frequency width W of the sync tone (the "red spike") is now
measured and displayed in Hz after DF in the main text box. In any
of the three JT65 modes, W should be no more than 2-4 Hz under good
conditions. Uncorrected frequency drifts, excessive oscillator
phase noise, and certain propagation effects can make the width
larger. Anything over about about 4 Hz will impair copy in JT65A.
Similarly, widths greater than about 7 and 15 Hz will begin to
impair copy in JT65B and C, respectively.
3. The utility program CWID.EXE now accepts lower case letters on the
command line. It also permits you to specify the audio frequency
of the tone in the wave file. You may wish to place the tone at
600 Hz or lower so that it lies well below the tones generated by
any of the WSJT operating modes.
4. The "Clip" function has been improved in several ways. The yellow
and magenta curves in the Big Spectrum display no longer disappear
when Clip > 0. Setting Clip = 3 does hard clipping, as before, but
it also blanks out any data regions with average power well above
the "baseline" of the green curve. Experimenting with different
values of Clip may help you to recover good copy from noisy data.
5. I believe that the text window displays in Monitor mode, and when
you are using the Include/Exclude buttons, now function correctly.
6. Minor bug fixes: the program no longer crashes in EME Echo mode if
you select "EME Calc | Load | Cancel". The correct "S" value is
listed on the status bar in JT6M mode.
7. The program's "Fit and finish" is improved in several not very
important ways.
WSJT Version 4.2.1
------------------
Version 4.2.1 contains a number of enhancements and bug fixes, mostly
related to the new JT65 mode. Changes from version 4.1.1 include the
following:
1.1 Message averaging now works correctly
1.2 Many small improvements to the decoding algorithm
1.3 Decoding speed improved by 50%
1.4 JT65 monitor mode is properly implemented
1.5 TX message can be changed up to t=59 s of preceding RX period
1.6 Switch to a shorthand TX message at any time
1.7 Freeze works properly for shorthand messages
1.8 Decodes with failed FEC (forward error correction) are
optionally displayable
1.9 "Garbage filter" provided so that questionable decodes appear
only if they contain some recognizable text
1.10 Automatic station ID, as in FSK441 and JT6M modes
1.11 Companion program to generate a CW ID.WAV file is included
1.12 The birdie zapper now works in JT65 mode
1.13 "Clip" function has been reactivated
1.14 F5 help screen updated to reflect JT65 practices
1.15 "OOO" message handled more transparently
1.16 Optional display of Moon Az/El at DX station, replacing Sun
Az/El
1.17 Right/Left audio out now works properly
1.18 DT displayed as blank rather than 0.0 for shorthand
messages
1.19 No program crash if ToRadio or Grid left empty
1.20 No program crash if attempting to decode 60 s file in JT6M
1.21 All other reported problems causing crash have been fixed
+-------------------------------------------------------------+
| Quick Start Guide to Using WSJT version 4 and the JT65 Mode |
+-------------------------------------------------------------+
Version 4 of WSJT marks a significant departure in the program's
evolution. The list of features is no longer a full superset of
those available in all previous versions. In particular, the
JT44 mode is gone; it is replaced by a new mode called JT65 that
I hope will be a significant improvement for making QSOs via EME
and extremely weak tropospheric paths.
The procedure for upgrading to version 4 is identical to previous
upgrades, with one exception: the setup procedure will install a
new program in your existing WSJT directory, but will keep the
old version alive as well. The two versions of the program can
coexist peacefully. During a testing period you will probably
want the older version and JT44 to be available as well.
What is different about JT65, compared to JT44? Here's a short
list:
1. T/R period 60 s; actual TX audio duration 46.8 s. (Yes, this
will put somewhat more stress on your PA. If its cooling is
marginal, take appropriate action.)
2. Modulation uses 64 data tones plus a sync tone.
3. Tones are spaced by 2.7 Hz in frequency and 0.372 s in time.
The total occupied bandwidth of a JT65 signal is about 180 Hz.
4. Transmissions consist of 63 data tones or "symbols," each
carrying 6 bits of information. In addition there are 63 sync
symbols for establishing time and frequency synchronization.
5. Software AFC (automatic frequency control) can follow drift
rates up to about +/-10 Hz/minute.
6. User messages are tightly "source coded" into 72 bits.
7. Strong FEC (forward error correction) coding is used to
mitigate transmission errors.
8. User-level message formats are designed to permit maximum
possible efficiency in EME or similar QSOs. A valid message must
be be one of three possible types:
1. "Call1 Call2 Grid" or "Call1 Call2 Grid OOO"
2. "RO", "RRR", or "73" (so-called shorthand messages)
3. "any text you want" (up to 13 characters selected
from a 42-character alphabet)
Instead of a callsign, the first field of a message type 1 may
contain "CQ" or "QRZ". Other such "special tokens" may be added
later. The available alphabet of characters for message type 3
is:
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ +-./?
9. Instead of JT44's very effective intra-message averaging of
the even, odd, and "last N" characters of a message, JT65 offers
even more powerful special shorthand messages for RO, RRR, and
73. These have much higher sensitivity than the other message
types. They work reliably down to about -30 dB. If you
succeed in exchanging callsigns and "OOO" by means of type 1
messages, you should certainly be able to complete the QSO.
10. Message averaging over subsequent transmissions works as it
did in JT44, with one exception. The "OOO" signal report
typically used for EME can be appended to message #1 and the
message will continue averaging without any need to start over.
The presence or absence of "OOO" will be detected if sync is
achieved, whether or not full decoding has been successful.
11. Receiving FEC-decoded transmissions takes some getting used
to. You will find *much* less gibberish on your screen in JT65
than in JT44. The FEC algorithm has a good idea whether it has
succeeded or not, and the program will suppress output unless it
is "pretty sure" that it has got the message right. You will
discover that when the FEC procedure fails and the program has
not realized it, text is occasionally produced looks like
plausible (but quite wrong) callsigns or grid locators. You must
mentally reject such garbage messages, when they occur. In the
small amount of on-the-air testing that JT65 has enjoyed so far,
my experience is that that only a few percent of decoded messages
are displayed incorrectly. Most of the time, received text is
either "letter perfect" or is left blank.
12. You may optionally have the program display text for instances
when the decoder in uncertain of its results. Doing so makes use of
an "expected message", and you can specify a minimum number of
characters thst must match before uncertain text is displayed. By
default the expected message is "MyCall HisCall HisGrid" where MyCall
is your own callsign, HisCall is the one entered in the onscreen "To
Radio" box, and HisGrid is the first four characters of the grid
locator in the "Grid" box.
13. At least one design choice used to define the JT65 algorithm is
still subject to change. If the 2.7 Hz tone spacing turns out to be
problematic because of propagation anomalies or inadequate oscillator
stabilities, the spacing could be increased. There are significant
advantages to the smaller spacing, however, so I am sticking with it
for now.
Beta Release 4.1.1
------------------
+-------------------------------------------------------------+
| Quick Start Guide to Using WSJT version 4 and the JT65 Mode |
+-------------------------------------------------------------+
Version 4 of WSJT marks a significant departure in the program's
evolution. The list of features is no longer a full superset of
those available in all previous versions. In particular, the
JT44 mode is gone; it is replaced by a new mode called JT65 that
I hope will be a significant improvement for making QSOs via EME
and extremely weak tropospheric paths.
The procedure for upgrading to version 4 is identical to previous
upgrades, with one exception: the setup procedure will install a
new program in your existing WSJT directory, but will keep the
old version alive as well. The two versions of the program can
coexist peacefully. During a testing period you will probably
want the older version and JT44 to be available as well.
What is different about JT65, compared to JT44? Here's a short
list:
1. T/R period 60 s; actual TX audio duration 46.8 s. (Yes, this
will put somewhat more stress on your PA. If its cooling is
marginal, take appropriate action.)
2. Modulation uses 64 data tones plus a sync tone.
3. Tones are spaced by 2.7 Hz in frequency and 0.372 s in time.
The total occupied bandwidth of a JT65 signal is about 180 Hz.
4. Transmissions consist of 63 data tones or "symbols," each
carrying 6 bits of information. In addition there are 63 sync
symbols for establishing time and frequency synchronization.
5. Software AFC (automatic frequency control) can follow drift
rates up to about +/-10 Hz/minute.
6. User messages are tightly "source coded" into 72 bits.
7. Strong FEC (forward error correction) coding is used to
mitigate transmission errors.
8. User-level mesage formats are designed to permit maximum
possible efficiency in EME or similar QSOs. A valid message must
be be one of three possible types:
1. "Call1 Call2 Grid" or "Call1 Call2 Grid OOO"
2. "RO", "RRR", or "73" (so-called shorthand messages)
3. "any text you want" (up to 13 characters selected
from a 42-character alphabet)
Instead of a callsign, the first field of a message type 1 may
contain "CQ" or "QRZ". Other such "special tokens" may be added
later. The available alphabet of characters for message type 3
is:
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ +-./?
9. Instead of JT44's very effective intra-message averaging of
the even, odd, and "last N" characters of a message, JT65 offers
even more powerful special shorthand messages for RO, RRR, and
73. These have much higher sensitivity than the other message
types. They work reliably down to -30 dB and below. If you
succeed in exchanging callsigns and "OOO" by means of type 1
messages, you should certainly be able to complete the QSO.
10. Message averaging over subsequent transmissions is intended
to work as it did in JT44, with one exception. The "OOO" signal
report typically used for EME can be appended to message #1 and
the message will continue averaging without any need to start
over. The presence or absence of "OOO" will be detected if sync
is achieved, whether or not full decoding has been successful.
[Note: message averaging is only partially functional in the
first beta release of the JT65 mode. I will need some experience
with the mode in order to optimize the code here.]
11. Receiving FEC-decoded transmissions takes some getting used
to. You will find *much* less gibberish on your screen in JT65
than in JT44. The FEC algorithm has a good idea whether it has
succeeded or not, and the program will suppress output unless it
is "pretty sure" that it has got the message right. You will
discover that when the FEC procedure fails and the program has
not realized it, text is occasionally produced looks like
plausible (but quite wrong) callsigns or grid locators. You must
mentally reject such garbage messages, when they occur. In the
small amount of on-the-air testing that JT65 has enjoyed so far,
my experience is that that only a few percent of decoded messages
are displayed incorrectly. Most of the time, received text is
either "letter perfect" or is left blank.
12. The program makes use of what it calls the "expected
message". By default this message is "MyCall HisCall HisGrid"
where MyCall is your own callsign, HisCall is the one entered in
the onscreen "To Radio" box, and HisGrid is the first four
characters of the grid locator in the "Grid" box. The AFC
algorithm, in particular, can work more effectively when the
actual message received matches the expected message.
13. Several design choices used in defining the JT65 algorithm
are still subject to change. If the 2.7 Hz tone spacing turns
out to be problematic because of propagation anomalies or
inadequate oscillator stabilities, the spacing could be
increased. About 1 dB of additional S/N could be obtained by
omitting the "Grid" field of the standard message format. This
would also reduce the maximum "plain text" message length from 13
characters to 10.
14. Please note that the "Clip" and "ST" are not functional in
WSJT v4.1.1. Their settings do not affect program operation.
Beta Release 3.8.1
------------------
This release contains the following new features:
1. An optional large spectral display. Its axes are reversed with
respect to those of the FSK441 and JT6M waterfall displays; in the new
plot, frequency runs from left to right and time from top to bottom.
2. A new birdie zapper that is especially effective in the FSK441 and
JT6M modes. You can watch what it is doing by observing the waterfall
displays before and after the "Zap" box is checked. Click "Decode" to
refresh the displays after checking or uncheking "Zap".
3. Message decoding in FSK441 mode has been improved in several ways.
DF is more accurately determined. Better synchronization is achieved
with the precise timing of 25-sample tone bursts comprising each
message symbol. Folding of messages is no longer attempted. (It
seems that whenever a ping is long enough to make folding effective,
it's also strong enough to make folding unnecessary.) As in previous
versions, the left mouse button allows decoding of single-tone
messages while the right button suppresses them.
4. It is now permissible to click "Gen Std Msgs" while transmitting in
FSK441 or JT6M mode. When this button is clicked, the Tx message
number will reset to #1 if and only if the callsign in "To Radio" has
changed.
5. Message formatting templates for FSK441 and JT6M may now include
the special codes %G and %L to insert your 4-digit grid or full
6-digit locator, respectively, in the message.
6. "Reset Defaults" now resets the QRN level to 5, as it should.
7. The decoding parameters in use are no longer listed in the Status
Bar at lower right. This listing had become redundant.
8. In Monitor mode, the name assigned to the Rx wave file begins with
"Mon_" instead of the "To Radio" callsign.
9. In FSK441 mode, all messages with more than 3 non-blank characters
are transmitted in multi-tone mode.
Beta Version 3.6.4
------------------
The previous version had the threshold set very low for all mouse-picked
decoding attempts in JT6M mode. This was useful to me for testing, but
produced excessive gibberish. Version 3.6.4 has a reasonable threshold and
produces much cleaner output. In addition, the message averaging algorithm
has been improved. I find that I seldom need to use either "Freeze" or
"FixAve" now. These buttons are still present in version 3.6.4, but unless
I hear that people are finding them useful I may remove them soon.
An option has been added to the Setup menu so that you can determine
whether you want the "Tx Stop" button to kick you out of Auto Mode, or
not. The default is not to do so.
***IMPORTANT***
If you can make WSJT v3.6.4 crash in normal operation, please let me know
(and tell me how). Also let me know if you find anything that does not
work as intended. I believe the present code behaves well and is nearly
ready to be upgraded from "Beta" status to a full release.
WSJT Beta Version 3.6.3
-----------------------
Version 3.6.3 has a number of small improvements, many of them not
immediately visible. Several bugs have been exterminated. The JT6M
decoder works better and is more sensitive. JT6M now has a "FixAve"
checkbox; when this is checked, average messages will be sought only
at the lengths of the automatically generated messages.
WSJT Beta Version 3.6.2
-----------------------
Version 3.6.2 corrects a problem that on a few machines caused a
fatal error that could only be corrected by deleting the initialization
file, WSJT361.INI.
WSJT Beta Version 3.6.1
-----------------------
Version 3.6.1 corrects a problem that caused an immediate termination
on program startup on some users' machines (typically older ones). If
you need this upgrade, you need it bad!
It also fixes a minor bug that could cause a divide-by-zero error if
you clicked on the plot area when no data was available to analyze.
WSJT Beta Version 3.6.0
-----------------------
The JT6M mode is only a week old, but many hundreds of QSOs have been
made with it all over the world. This mode is expressly designed for
meteor scatter on 6 meters, but it may be useful with some other
propagation modes as well. It has characteristics that place it about
midway between FSK441 and JT44 in both speed and sensitivity. A
second beta release of WSJT with JT6M, Version 3.6.0, is now available
for downloading at
http://pulsar.princeton.edu/~joe/K1JT/UPD360.EXE
The download file is about 0.75 MB in length.
Comparison of Versions 3.6.0 and 3.5.1
--------------------------------------
1. Version 3.6.0 has a better and faster decoder for JT6M. Further
improvements in this area are still to come.
2. Several bugs that could cause crashes in V3.5.1 have been fixed.
Version 3.6.0 appears to be quite stable (at least on my own
computers).
3. Some buttons have been moved from their familiar positions.
4. Gadgets that Microsoft calls "Up-Down Controls" have replaced the
+/- buttons used for various decoding parameters.
5. You can now drag the mouse pointer across any portion of the large
plot area to cause decoding of that portion of a recorded file. This
works in both FSK441 and JT6M mode. The area you selected is marked
when the plot is refreshed.
6. A yellow curve now appears above the green curve in JT6M mode. The
yellow line represents measured power received at the sync-tone
frequency and in the sync-tone intervals.
I haven't yet written up any detailed instructions for the JT6M mode.
However, if you are an experienced WSJT user you probably won't need
any. Here are a few things it will be helpful to know about JT6M.
1. Like JT44, JT6M uses 44-tone FSK with a "sync tone" and 43 possible
data tones -- one for each character in the supported alphanumeric
set. The sync tone is at 1076.66 Hz, and the 43 other possible tones
are spaced at 21.53 HZ intervals up to 2002.59 Hz. The tones are
keyed at a rate of 21.53 baud, so each one lasts for 1/21.53 = 0.04644
seconds. The sync tone is ON during every 3rd transmission interval;
tones representing two data characters follow each sync tone. The
transmission rate of user data is therefore (2/3)*21.53 = 14.4
characters per second. The transmitted signal sounds a bit like
piccolo music.
2. Basic operation is very similar to FSK441. Just select JT6M from
the WSJT "Mode" menu (or use "Shift-F7") and then proceed as usual.
3. The green line and waterfall display have their usual meanings.
4. The program attempts to decode both single pings and an "average
message". The average is the last line displayed during each decoding
attempt, and is flagged with an asterisk as in FSK441. The number to
the right of the asterisk is the inferred message length (for example,
the number should be 10 for the message "W8WN K1JT "). If the program
finds the wrong length, the average will be garbled or meaningless.
All message lengths should be even numbers, because odd-length
messages are padded with an extra space at transmission time in order
to make them even.
5. Clicking with the left mouse button decodes a 4-second block of
data near the mouse pointer. The right button uses a longer segment
of 10 seconds. Drag the mouse with the button down to select any
desired region. Experiment for best decoding as necessary.
6. As soon as you see some properly decoded text, set the DF box to
the measured DF and check the "Freeze" box. Alternatively, you can
set the Tolerance to a low value (say 25 Hz) after the desired signal
has been identified. Use RIT, if necessary, to bring subsequently
measured DF's down to a small value.
7. Default settings for the decoder are S > -12 dB, Tol=400 Hz, DF=0
Hz.
8. JT6M can work with signals that are up to 13 dB weaker than those
required for FSK441. In the brief on-the-air tests I've made with
W8WN, we have both found that mouse-clicking on the smooth green line,
even where nothing was heard and nothing can be seen, sometimes causes
both callsigns to pop up out of the noise!
Version 3.0
-----------
A new major release of WSJT, Version 3.0, is now available for free
download. Instructions for upgrading and for complete installations
can be found at http://pulsar.princeton.edu/~joe/K1JT.
What's new in Version 3.0?
--------------------------
1. The "User's Guide and Reference Manual" has grown to 51 well
illustrated pages. The new manual includes four major new
sections which together cover:
a) the EME Echo mode, including the "Measure" sub-mode and the
"EME Calc" utility for estimating the strength of your echoes
from the moon;
b) the nature of the various astronomical calculations done within
WSJT, and a summary of their accuracies;
c) several pages describing availability of Fortran source code for
the DSP algorithms in WSJT, as well as a suite of test programs
for generating simulated data and testing the FSK441 and JT44
encoding and decoding algorithms;
d) a short essay on possible future developments for WSJT.
2. The astronomical calculations in WSJT have been overhauled and thoroughly
checked. In practice the differences from V2.9 will seem minor, but as
described in the new manual's Appendix B, the accuracies of
computed positions for the sun and moon, and for the EME Doppler
shift, are now well documented. Computed positions are accurate to
within about 0.04 degrees, and Doppler is better than 1 Hz at 144
MHz. Exactly what is meant by the displayed data is now described
in the manual, as well.
3. A new feature has been added on the Help menu. It pops up a screen
summarizing the standard message exchanges used for minimal QSOs
using FSK441 and JT44. No more excuses for not being sure about which
message you should send next!
4. The Measure mode can now be left running indefinitely, with its output
written to a file. A few individuals have been wanting to use the
program for radio astronomy purposes, and the new version provides a
minimal facility for doing this.
5. The display screen for the EME Calc utility has been cleaned and
tightened up.
6. A few other small niceties, all minor in scope.
Version 2.9.0
-------------
I am pleased to announce the availability of an upgrade to WSJT
Version 2.9. The upgrade provides most of the features of the
soon-to-be-released Version 3.0; I am releasing it now as Version 2.9
because many users have asked for early access to its new
capabilities. A full release of Version 3.0 must await some updating
of the Users Guide and Reference Manual. Probably a few additional
features will be added by then, as well. Please be patient!
Version 2.9 is available only as an upgrade. As usual, it can be
downloaded from the WSJT web site,
http://pulsar.princeton.edu/~joe/K1JT, or from the European mirror
site http://www.dk5ya.de. New features of the program include the
following:
1. EME Echo mode now works on certain computers (generally older,
slower ones) that previously refused to run Echo mode properly. The
new version runs fine under Windows 95 on my ancient 100 MHz Pentium
with 32 MB of RAM.
2. A new feature known as "Measure" can be selected from the main
screen in EME Echo mode. Click the Measure button and your system
will record the received audio for one second, compute the level of
the noise and display the result in units of dB relative to the
nominal WSJT "0 dB" level. The program will repeat this measurement
cycle every 2 seconds and plot the results as a green line in the
graphical screen area. You can use this mode to measure Sun noise,
antenna temperature, ground noise, preamp gain, and a host of other
useful quantities, relative to a chosen reference level.
3. A pop-up utility labeled "EME Calc" can be selected from the EME
Echo screen. It provides an easy way to predict whether you should be
able to detect your own echoes from the moon, as well as your ability
to work another station by EME. Boxes are provided to enter your TX
power, TX feedline loss, RX noise figure, RX feedline loss, antenna
gain, ground gain, ground noise, and sky temperature. Similar
quantities can be entered for a second station, and you must also
specify the operating frequency. When you click "Compute," the
program will calculate the maximum expected echo strengths for the
"Home Station" and the "DX Station" individually, as well as the
maximum expected signal strength of each station at the other
location. The program also estimates the averaging time that would be
required to detect echoes at the predicted signal level.
Signal strengths are quoted relative to the WSJT standard, the noise
power in a 2500 Hz bandwidth. If the computed result for your echo
exceeds about -38 dB, you have a chance of being able to detect your
echoes using WSJT. In comparison, echoes are detectable by the human
ear only if they exceed about -14 dB on the same scale, or
equivalently +3 dB in a 50 Hz bandwidth. Note that the estimated
signal strengths are supposed to be the maximum values expected for
the specified conditions. There are many reasons (Faraday rotation,
ionospheric scintillation, libration fading, ...) why the actual
signal strength may be different, and deviations are much more likely
to be downward than upward. The predicted echo strength for my
present 144 MHz station at a reasonably good time of the month is
around -25 dB. My experience has been that the predictions are fairly
good if enough time is spent to be sure of catching a Faraday rotation
peak.
A number of smaller enhancements have been made in the EME Echo mode
of WSJT. These include the following:
4. The program is much better behaved when operating at higher
frequencies, in particular 1296 MHz and above. If you fail to enter
an RIT setting or specify one that would make the return echo fall
outside the audio frequency range 900 - 2100 Hz, the program will
suggest a better RIT value for you to use.
5. The amount of programmed frequency spread of your transmitted
signal (the "Dither" magnitude) can be set to any value in the range 0
to 500 Hz. It defaults to 50 Hz.
6. Instead of accumulating average echo parameters indefinitely, you
can set a parameter "Tavg" that specifies a time constant for
averaging. The default value is 5 minutes; at this setting the
average echo spectrum will build up as before for the first 5 minutes,
but thereafter it will track the signal characteristics over the most
recent 5 minutes. In other words, the average gradually "forgets" the
signals received more than Tavg minutes ago. Setting Tavg to a large
number, say 999 minutes, will closely approximate the program's
previous behavior. If you can detect your EME echoes easily and want
to see how they vary with time, you might set Tavg to 1 minute, start
a "Measure" sequence, and take down the signal level readings at one
minute intervals.
7. Information sent to the main text window every 6 seconds now
accumulates, with the text window scrolling as necessary. The output
is also (optionally) written to file DECODED.CUM so that you can study
the data later.
Other miscellaneous improvements and bug fixes include the following:
8. In JT44 mode, if the "Grid" box is left empty then no EME Doppler
shift will be displayed.
9. The minimum "Dsec" increment has been reduced from 1 second to 0.5
second. This will permit more precise on-the-fly correction of the
Windows clock for use by WSJT, should that be necessary.
10. JT44 messages are always exactly 22 characters in length, and any
additional characters are ignored. To make this behavior more
obvious, any excess characters are now visibly removed from the screen
when transmission of a message begins.
11. In Version 2.3.0, hitting the F4 key while in echo mode would
cause the program to crash. Fixed.
12. Switching between modes could cause the Auto Period button to be
stuck in the disabled or "grayed out" state. Fixed.
13. The last character in a manually edited FSK441 message was not
sent if the default trailing blank and "<" character were erased.
Fixed.
Version 2.3.0
-------------
This release of WSJT is the first to include the EME Echo mode. This
mode allows you to detect and measure your own lunar echoes, even if
they are far too weak to hear. The mode can be highly useful for
evaluating your station performance, even if you prefer to use CW
rather than JT44 for your EME QSOs.
If you are a present user of WSJT with no interest in detecting and
measuring your EME echoes, you will find no significant advantages to
upgrading to WSJT Version 2.3.0. With the exception of a minor bug
fix, the FSK441 and JT44 modes are essentially unchanged.
You can download the upgrade from the WSJT home page,
http://pulsar.princeton.edu/~joe/K1JT, and soon also from the European
mirror site http://www.vhfdx.de/wsjt. To upgrade an existing WSJT
installation of Version 1.9.4 or later you should download and execute
the file UPD230.EXE, which will replace your existing files WSJT.EXE
and WSJT1.DLL with new files of the same name.
I have not yet produced a new full distribution of the latest version.
Doing this will require extensions to the User's Guide and Reference
Manual, and will probably be accompanied by further improvements to
the program. If you wish to do a full installation of Version 2.3.0
from scratch you should download the installation file WSJT222.EXE,
run it to install Version 2.2.2, and then upgrade to Version 2.3.0 as
described above.
Minor Bug Fix: In WSJT Version 2.2.2 and earlier, if you dismissed the
"Setup | Options" page by clicking on the "X" in the upper right
corner of the form, instead of by clicking the "Done" button, the home
station callsign ("My Call") would revert to its default value "K1JT".
(Contrary to popular opinion, this was not an subtle ploy designed to
increase my own VUCC totals; it was simply a coding mistake.) The bug
has now been fixed.
EME Echo mode is presently a plain, no-frills implementation. You can
activate it from the Mode menu or by striking function key F9. Most
of the familiar WSJT buttons will then disappear from the screen,
leaving just a few that are essential for controlling the Echo mode.
If your station is already operational in the FSK441 and JT44 modes
and you have provided the proper signal levels, all you need to do for
an echo test is to start WSJT Version 2.3.0, hit F9 to switch to EME
Echo mode, aim your antenna at the moon, pick a clear frequency, and
toggle Auto Period On. The program will then start cycling through
the following loop:
1. Transmit a fixed tone for 2.0 s
2. Wait about 0.5 s for the start of your echo
3. Record the received signal for 2.0 s
4. Analyze and plot the results
5. Repeat from step 1
The loop cycle time is 6 seconds, so the transmitter duty cycle is
only 2/6 or 33%. Your transmitter will think it is loafing. At the
start of each transmission the frequency of the transmitted tone is
randomly dithered by an offset up to +/- 100 Hz around a nominal value
of 1500 Hz. The programmed offset is removed from the computed
spectrum of each recording before it is added into the accumulating
average. This procedure helps to minimize the effect of birdies in
the receiver passband: in the average spectrum a fixed-frequency
birdie will be smeared out over a 200 Hz range, while the desired
signal remains sharply defined.
Two curves are plotted in WSJT's main plot area during each pass
through the Tx/Rx loop. Each represents the spectrum of received
power over a 400 Hz range centered on the expected echo. The curve in
gray is a reference spectrum that you can use to be sure you have
chosen a reasonably birdie-free passband. It is aligned so as to
remove the EME doppler shift computed at the start of your run. The
alignment will not be subsequently adjusted for changes in doppler
shift or for the random dithering of the transmitted frequency.
Stable birdies will therefore stay fixed in the blue spectrum, making
them easy to recognize and evade if necessary. The red curve displays
the desired EME echo signal. Spectra computed for each 2-second
receive period are shifted to correct for changing doppler shift and
for the programmed frequency dithering, and are then averaged. The
EME echo should appear as a narrow spike near the middle of the red
curve, close to DF = 0.
In addition to the graphical display, a line is presented in the WSJT
text window in the following form:
N: 16 Sig: -26.3 dB DF: -1.3 Hz Width: 0.7 Hz Q: 9
This information gives the number N of Tx/Rx cycles that have been
averaged, the mean signal strength in dB, the measured frequency
offset of the detected echo from the expected frequency, the spectral
width of the echo, and a relative quality indicator for the detection
on a 0 - 10 scale. Signal strength is measured in the same units as
used in the FSK441 and JT44 modes, i.e., in dB relative to the
received noise power in a 2500 Hz bandwidth. Low values of Q
represent dubious detections, in which case the values of signal
strength, DF, and width may be meaningless.
A note about doppler calculations will be helpful here. Most computer
programs in amateur EME stations use approximate formulae to compute
the position and distance of the moon and the expected doppler shifts
of echos. WSJT is no exception, and I cannot presently quote a firm
figure on the accuracy of its doppler calculations or describe how
their errors depend on lunar coordinates or the accuracy of your
station location. EME Echo mode uses a calculated doppler shift to
align received spectra so that the echo should appear at DF = 0. I
have found that on 2 meters the return signals generally fall within
10 Hz of DF = 0. Further improvements in accuracy of the doppler
routine will be forthcoming.
If you can hear your own EME echoes you should see a spike in the red
curve within a few seconds after toggling Auto Period On. If your
echoes are 10-15 dB below the audible threshold you should see a
significant spike on the red curve within a few minutes. To give you
a better example of what to expect, consider the parameters of my
station. On 2 meters I run up to 400 Watts to a 17.6 dBd antenna (4 x
9 el yagis) aimed at the horizon. I have never heard my own CW echoes
with this system. However, when the moon is in my elevation window at
0 - 10 degrees I can easily detect my echoes at any time of the month
using WSJT in its EME Echo mode. Indeed, I can turn off the PA and
use my FT-847 barefoot, delivering 35 W to the antenna, and still
detect my echoes rather easily, even with the moon in a "bad" part of
the sky and the path degradation as large as -8 dB. I seem to be able
to detect my echoes reliably down to relative signal levels around -36
dB.
The spectral analysis done in EME Echo mode provides a frequency
resolution of 0.67 Hz. If your transmitter or receiver has short-term
frequency stability much worse than this value, so that something
drifts or wobbles by more than about 1 Hz in 2 seconds, your echo
sensitivity will be degraded. Most modern radios have no difficulty
in meeting this standard on the 6 and 2 meter bands, but the higher
UHF and microwave bands will be more problematic. I don't have enough
experience to know what the spectral width of an echo on the 432 MHz
or 1296 MHz band should be after averaging for a few minutes. I have
been measuring widths of 2 Hz or less on 2 meters.
By default WSJT will assume that your receiver and transmitter are
tuned to the same frequency. An on-screen box labeled "RIT (Hz)" is
provided so that you can inform the program of any offset receiver
tuning, for example to accommodate a large doppler shift. Suppose you
are running a test on 70 cm and the predicted doppler shift at the
start of the run is -1087 Hz. That would cause echoes from the 1400 -
1600 Hz transmitted audio tone to come back as low as 313 Hz, probably
well below the low-frequency cutoff in your receiver's passband. Use
your transceiver's RIT control to offset the receiver tuning by some
round number within a few hundred Hz of the predicted value -- say
-1000 Hz in this example -- and enter this offset in the RIT box
before starting the echo measurement. The program will accommodate
subsequent changes in the doppler shift up to 800 Hz or so, if
necessary, without any further adjustments. Your echo should appear
at the center of the red curve, as usual. You won't need to use
the RIT feature on 6 or 2 meters, where doppler shifts are much
smaller and echoes always fall well within the receiver's SSB
passband.
Please note that I have so far tested the EME Echo mode only on 2
meters. You will discover that the software implementation is not yet
highly polished; a number of improvements are already in the works,
but I want to gain the advantage of feedback from other users before I
go too much further. If you use the EME Echo mode -- especially on
bands other than 2 meters -- please send me your comments,
experiences, and suggestions! I am anxious to know how well it works
for you.
Version 2.2.2
-------------
This is a minor maintenance release. As usual, you can download it
from the WSJT web page, http://pulsar.princeton.edu/~joe/K1JT. In
addition to a short update file, UPD222.EXE, a full distribution of
WSJT Version 2.2.2 is available as WSJT222.EXE.
I had thought that Version 2.2.1 had already fixed a sometimes
baffling bug appearing in earlier versions: if WSJT was terminated
when in its "minimized" state, it could get "stuck" on your Windows
taskbar and refuse to return to a full size display.
It's not always easy for me to test program revisions on all available
versions of Windows, and it seems that the V2.2.1 fix did not solve
the problem on at least some versions of Windows 98. This time, with
V2.2.2, I believe it's *really* fixed!
If WSJT is stuck in the minimized state you should fix it as follows,
and then upgrade to Version 2.2.2:
A) Start WSJT. It should appear in minimized form on the taskbar at
the bottom of your screen.
B) Right-click on the WSJT taskbar label and select "Move".
C) Press the "left arrow" and/or "up arrow" keys a few times and
then move the mouse. You should start to see a "dotted frame"
indicating the location of the WSJT screen.
D) Click the left mouse button, and you should be back in business.
Then you should download and install UPD222.EXE and upgrade your
system to Version 2.2.2.
Version 2.2.1
-------------
This is a minor maintenance release. You can download it from the
WSJT web page, http://pulsar.princeton.edu/~joe/K1JT. In addition to
the short update file, a new full distribution of WSJT Version 2.2.1
is available, as well as a new version of the manual addressing the
new program features.
As always, I will be pleased to receive comments and suggestions at
email address k1jt@arrl.net. Please note, however, that I will be on
vacation and not reading email from July 7 through 21.
Version 2.2.1 fixes the following minor bugs in Version 2.2.0:
1. When first started without a valid INI file, the v2.2.0 would fail
to "Generate Std Messages" when asked to do so. Once you have
switched modes, say from FSK441 to JT44, the program worked correctly.
2. Local hour angles greater than 180 degrees are now displayed as
negative angles.
3. If you did not check the menu item "File | Save text in File
DECODED.CUM", the v2.2.0 would create an unwanted file named "fort.21"
and write all decoded JT44 text there.
4. If WSJT was terminated when in the "minimized" state, it could get
"stuck" on your Windows taskbar. If you are stuck in this mode you
should fix it as follows, and then upgrade to Version 2.2.1:
A) Start WSJT. It should appear in minimized form on the taskbar at
the bottom of your screen.
B) Right-click on the WSJT taskbar label and select "Move".
C) Press the "left arrow" and/or "up arrow" keys a few times and
then move the mouse. You should start to see a "dotted frame"
indicating the location of the WSJT screen.
D) Click the left mouse button, and you should be back in business.
Version 2.2.0
-------------
WSJT Version 2.2.0 provides several significant enhancements, a number
of smaller improvements, and four minor bug fixes.
To upgrade to v2.2.0 you should download the self-extracting zip file
UPD220.EXE and execute it to extract its contents, directing the
resulting files to your WSJT installation folder.
The new version includes the following changes:
1. The JT44 mode now has an adjustable parameter called "Clip." It
can be controlled with +/- buttons just below analogous ones for the
"Sync" parameter. The value of Clip defaults to 0, where it has no
effect. By increasing Clip to 1, 2, or 3 you can introduce "soft,"
"moderate," or "hard" clipping of any sudden increases in signal
strength that might ruin the decoding of an otherwise usable signal.
I have found that setting Clip to 2 or 3 permits me to use JT44 in the
presence of summertime QRN that renders v2.0.1 useless. Clipping also
helps to accommodate occasional meteor pings in a JT44 QSO, recovering
the program's ability to synchronize on a weak residual signal. You
can leave the clipping turned on; note, however, that using hard
clipping on a signal that does not require it can cost you about 1 dB
in message S/N. I recommend generally leaving Clip set to 0 and
increasing it only when necessary.
2. JT44 mode has a new checkbox labeled "Zap Birdies." It does just
what you would hope such a command would do -- and it can turn a
totally spoiled signal into good copy! (In the upgrade file I've
included an example wave file recorded via EME from W7FG, in the
presence of a strong birdie at my station. To become a believer, try
decoding this file both with and without "Zap Birdies" checked. He
was sending me the message "K1JT W7FG EM26 ".)
The Zap algorithm works best with birdies that are steady in both
amplitude and frequency. A sure indicator that you have a birdie
problem is a persistent extra spike (or spikes) in the red-line plot,
in addition to the one corresponding to the JT44 sync tone. If the
birdie is higher in frequency than the sync tone by 20 to 465 Hz, you
will probably see a number of identical garbage characters in the line
of decoded text. If this happens, check the "Zap Birdies" box and hit
"Decode Again", and your copy should improve. It will work best if
you have already identified the correct value of DF and checked the
"Freeze" box to lock onto the Sync tone.
Do not expect miracles! Keeping birdies out of your receiver or
QSYing to avoid them will always work better than trying to deal with
them in software. Nevertheless, this birdie-killer can make the
difference between a successful QSO and one that fails miserably.
3. The JT44 mode has a second new checkbox labeled "Fold Msg." For
messages having identical content in the first and second half, this
feature can yield a signal-to-noise improvement of 1.5 dB. The JT44
default message formats have been modified slightly to maximize the
opportunities for useful message folding. For example, if K1AA is
working G2ZZ, the first EME-style message will now be generated as
"G2ZZ K1AA G2ZZ K1AA ". (Notice the two spaces in the middle of the
message and at the end.) If the "Fold Msg" box is checked, the
message will be decoded simply as "G2ZZ K1AA ". Try decoding a
marginal signal both with and without the "Fold Msg" box checked. QSB
conditions might make one or the other preferable at a particular time.
4. In WSJT versions 2.0.0 and 2.0.1 the JT44 decode algorithm produces
a single-character average of the last four character positions in a
message. In Version 2.2.0 the averaging limit has been changed to
equal the number of "O" characters (for EME messages) or "R"
characters (for non-EME messages) at the trailing end of default TX
message #2. For example, if clicking "Generate Std Texts" produces
"G2ZZ K1AA OOOOOOOOOOOO" for message #2, the program will produce a
single-character average based on the last 12 received character
positions. This choice gives you the best possible chance of properly
decoding an "O" or "R" report in message #2, and it also gives you a
good chance at snagging the "RRRRRRRRRRRRRRRRRRRRRR" message under
very marginal conditions. For steady signals the procedure can yield
a 5.4 dB S/N advantage over single characters and a 2.4 dB advantage
over the four-character average.
5. WSJT now remembers whether you were using FSK441 or JT44 mode when
you last exited the program. On startup it restores the most recently
used mode, including values of W, S, and Sync, as appropriate.
6. All decoded text in JT44 mode is now written to the cumulative file
DECODED.CUM. In previous versions of WSJT, text was saved only in
FSK441 mode.
7. The default Sync setting in JT44 mode is now 1 rather than 2.
I believe nearly everybody runs with Sync = 1.
8. WSJT v2.2.0 is more complete and more consistent about saving
information about the starting directory and the form size of the
"File | Open" dialog box.
9. The displayed azimuths for "Hot A" and "Hot B" (direction headings
to use for optimal sporadic meteor reflections) now wrap correctly at
0 and 360 degrees. You will no longer see, for example, values like
368 or -8 degrees if you are working someone to your north.
10. In JT44 mode the program now displays the local hour angle of the
Moon, in degrees. You will appreciate this if you have a polar
mounted EME array.
11. The UTC Offset may now be specified as a floating-point number --
that is, with significant digits after a decimal point.
12. The count of available records displayed in the average message
window behaved illogically when "Decode Again" and "Include" were used.
This has been fixed.
13. There was a bug in the JT44 display routine that caused error
messages to appear when the moon's right ascension was very close to
00:00. The error could appear at most once a month, and it would
persist for an hour or so. The bug has been fixed.
14. There was an apparent logical inconsistency in program behavior if
"Exclude" was clicked after "Clear Avg" had been executed. This has
been fixed.
15. In V2.0.1 if you hit F8 more than once and then hit F7, the
"Width" parameter in FSK441 mode would be set to 200 ms. This has
been fixed.
Version 2.0.1
-------------
This is a minor maintenance release. Principal changes from Version
2.0 include the following:
1. The installation scripts for both the full installation and the
upgrade to v2.0.1 are more robust and much easier to use.
2. The decoding parameters for FSK441 mode are saved correctly after
you have used JT44 mode.
3. The controls for "Decode Again", "Include", and "Exclude" are now
fully available during the Tx period.
4. Certain colors (e.g., the backgrounds of a few labels) now display
better on older machines.
5. The background colors behind certain Tx messages in JT44 mode
have been corrected.
6. The manual has been updated to conform with the new installation
scripts, and a number of other small changes (mostly correcting
typos) have been made.
7. The Tab key now moves the focus between various on-screen controls
and text boxes in a rational way.
Version 2.0
-----------
A major new release of WSJT, Version 2.0 is now available for free
download. Instructions for upgrading and for new installations can be
found at http://pulsar.princeton.edu/~joe/K1JT.
What's new in Version 2.0 ?
--------------------------
The JT44 mode for extreme weak signal work was first introduced in
beta release 1.8.0. This mode has now matured, the program is stable,
and tons of EME QSOs (among others) are being made with it. New
features and fixes in Version 2.0 include the following:
1. Full monitor mode with separate averaging of 1st and 2nd sequences.
2. Mouse-selected value of DF for decoding when "Freeze" is checked.
3. Program is much faster at certain critical points, and now runs
reliably on a 75 MHz Pentium with 24 MB of RAM.
4. The dreaded "always starts minimized" bug has been fixed.
5. Certain dates (such as "2002 VIII 21" now display properly in
machines configured for European format.
7. A number of other small niceties.
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