WSJT-X/doc/user_guide/en/tutorial-example2.adoc
2018-12-07 01:44:19 +00:00

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// Status=review
.Main Window:
- Select *JT9+JT65* on the *Mode* menu.
- Toggle the *Tx mode* button to read *Tx JT65 #*, and set the Tx and Rx
frequencies to 1718 Hz.
- Double-click on *Erase* to clear both text windows.
.Wide Graph Settings:
- *Bins/Pixel* = 7
- *JT65 .... JT9* = 2500
- Adjust the width of the Wide Graph window so that the upper
frequency limit is approximately 4000 Hz.
.Open a Wave File:
- Select *File | Open* and navigate to +...\save\samples\JT9+JT65\130610_2343.wav+.
The waterfall should look something like this:
//.130610_2343.wav Decode
[[X14]]
image::130610_2343-wav-80.png[align="left",alt="Wide Graph Decode 130610_2343"]
The position of the blue marker on the waterfall scale is
set by the spinner control *JT65 nnnn JT9*, where nnnn is an audio
frequency in Hz. In *JT9+JT65* mode the program will automatically
decode JT9 signals only above this frequency. JT65 signals will be
decoded over the full displayed frequency range.
JT9 signals appear in the *Cumulative* spectrum as nearly rectangular
shapes about 16 Hz wide. They have no clearly visible sync tone like
the one at the low-frequency edge of all JT65 signals. By convention
the nominal frequency of both JT9 and JT65 signals is taken to be that
of the lowest tone, at the left edge of its spectrum.
This sample file contains 17 decodable signals — nine in JT65 mode
(flagged with the character # in the decoded text windows), and eight
in JT9 mode (flagged with @). On multi-core computers the decoders
for JT9 and JT65 modes run simultaneously, so their results will be
interspersed. The *Band Activity* window contains all decodes (you
might need to scroll back in the window to see some of them). A
signal at the frequency specified by the green marker is given
decoding priority, and its message is displayed also in the *Rx
Frequency* window.
[[FigDecodes]]
image::decodes.png[align="center"]
- Confirm that mouse-click behavior is similar to that described
earlier, in <<TUT_EX1,Example 1>>. _WSJT-X_ automatically determines
the mode of each JT9 or JT65 message.
+
TIP: When you double-click on a signal in the waterfall it will be
properly decoded even if on the "`wrong`" side of the *JT65 nnnn JT9*
marker. The Tx mode automatically switches to that of the decoded
signal and the Rx and Tx frequency markers on the waterfall scale
resize themselves accordingly. When selecting a JT65 signal, click on
the sync tone at its left edge.
- Double-click on the waterfall near 815 Hz: a JT65 message
originating from W7VP will be decoded and appear in the *Rx Frequency*
window. Between the *UTC* and *Freq* columns on the decoded text line
you will find *dB*, the measured signal-to-noise ratio, and *DT*, the
signal's time offset in seconds relative to your computer clock.
[width="80%",align="center",cols="^10,2*^8,2*^10,54",options="header"]
|===
|UTC|dB|DT|Freq|Mode|Message
|+2343+|+-7+|+0.3+|+815+|+#+|+KK4DSD W7VP -16+
|===
- Double-click on the waterfall at 3196 Hz. The program will decode a
JT9 message from IZ0MIT:
[width="80%",align="center",cols="^10,2*^8,2*^10,54",options="header"]
|===
|UTC|dB|DT|Freq|Mode|Message
|+2343+|+-8+|+0.3+|+3196+|+@+|+WB8QPG IZ0MIT -11+
|===
- Scroll back in the *Band Activity* window and double-click on the
message `CQ DL7ACA JO40`. The program will set *Tx mode* to JT65 and
the Rx frequency to that of DL7ACA, 975 Hz. If you hold down the
*Ctrl* key, both Rx and Tx frequencies will be moved. If you had
checked *Double-click on call sets Tx Enable* on the *Setup* menu, the
program would configure itself to begin a transmission and start a QSO
with DL7ACA.
- Hold *Ctrl* down and double-click on the decoded JT65 message `CQ
TA4A KM37`. The program will set Tx mode to JT9 and the Rx and Tx
frequencies to 3567 Hz. The program is now configured properly for a
JT9 QSO with TA4A.
.Reopen the First Sample File:
- Select *File | Open* and navigate to `...\save\samples\130418_1742.wav`.
Taking full advantage of the wide-band, dual-mode capability of
_WSJT-X_ requires a receiver bandwidth of at least 4 kHz. These
data were recorded with a much narrower Rx bandwidth, roughly 200 to
2400 Hz. If you have no Rx filter wider than about 2.7 kHz, you will
be using data like this. For best viewing, adjust *Bins/Pixel* and the
width of the Wide Graph so that only the active part of the spectrum
shows, say 200 to 2400 Hz. Re-open the example file after any change of
*Bins/Pixel* or Wide Graph width, to refresh the waterfall.
The signals in this file are all JT9 signals. To decode them
automatically in *JT9+JT65* mode youll need to move the *JT65 nnnn JT9*
delimiter down to 1000 Hz or less.
.Waterfall Controls
Now is a good time to experiment with the *Start* control and the
sliders controlling gain and zero-point of the waterfall and spectrum
plots. *Start* determines the frequency displayed at the left side of
the waterfall scale. Sliders set the baseline level and gain for the
waterfall and the several types of spectra. Good starting values
should be close to mid-scale. You might want to uncheck *Flatten*
when adjusting the sliders. Re-open the wave file after each change,
to see the new results.