For this step and the next, you may want to pretend you are K1JT
by entering that callsign temporarily as *My Call* on the 
*Settings | General* tab.  Your results should then be identical to
those shown in the screen shot below.

.Open a Wave File:

- Select *File | Open* and select the file
+...\save\samples\JT9\130418_1742.wav+. When the file opens you should
see something similar to the following screen shot:

[[X12]]
image::main-ui.png[align="center",alt="Main UI and Wide Graph"]

.Decoding Overview

Decoding takes place at the end of a receive sequence and proceeds in
two steps.  The first decode is done at the selected Rx frequency,
indicated by the U-shaped green marker on the waterfall frequency
scale.  Results appear in both the left (*Band Activity*) and right
(*Rx Frequency*) text windows on the main screen. The program then
finds and decodes all signals in the selected mode over the displayed
frequency range. The red marker on the waterfall scale indicates your
Tx frequency.

Seven JT9 signals are present in the example file, all decodable.
When this file was recorded KF4RWA was finishing a QSO with K1JT.
Since the green marker was placed at his audio frequency, 1224 Hz, his
message `K1JT KF4RWA 73` is decoded first and appears in the *Rx
Frequency* window. The *Band Activity* window shows this message plus
all decodes at other frequencies.  By default lines containing `CQ`
are highlighted in green, and lines with *My Call* (in this case K1JT)
in red.

[[X13]]
.Decoding Controls

To gain some feeling for controls frequently used when making QSOs,
try clicking with the mouse on the decoded text lines and on the
waterfall spectral display. You should be able to confirm the
following behavior:

- Double-click on either of the decoded lines highlighted in
green. This action produces the following results:

** Callsign and locator of a station calling CQ are copied to the *DX
Call* and *DX Grid* entry fields.

** Messages are generated for a standard minimal QSO.

** The *Tx even* box is checked or cleared appropriately, so that you
will transmit in the proper (odd or even) minutes.

** The Rx frequency marker is moved to the frequency of the CQing
station.

** The *Gen Msg* ("`generated message`") radio button at bottom right 
of the main window is selected.

** If you had checked *Double-click on call sets Tx Enable* on the
*Setup* menu, *Enable Tx* would be activated and a transmission would
start automatically at the proper time.

** You can modify the double-click behavior by holding down the
*Shift* key to move only the Tx frequency or the *Ctrl* key to move
both Rx and Tx frequencies.

- Double-click on the decoded message `K1JT N5KDV EM41`, highlighted
in red.  Results will be similar to those in the previous step. The Tx
frequency (red marker) is not moved unless *Shift* or *Ctrl* is held
down.  Messages highlighted in red are usually in response to your own
CQ or from a tail-ender, and you probably want your Tx frequency to
stay where it was.

NOTE: Double-clicking on decoded messages can be defaulted to simplex
operation by checking *Double click on call sets Tx and Rx freqs* on
the *Settings -> General* tab.

NOTE: You can prevent your Tx frequency from being changed by checking the
box *Lock Tx Freq*.

- Click somewhere on the waterfall to set Rx frequency (green marker
on waterfall scale).

- Shift-click on the waterfall to set Tx frequency (red marker).

- Ctrl-click on the waterfall to set both Rx and Tx frequencies.

- Double-click on a signal in the waterfall to set Rx frequency and
start a narrow-band decode there. Decoded text will appear in the
right window only.

- Ctrl-double-click on a signal to set both Rx and Tx frequencies and
decode at the new frequency.

- Click *Erase* to clear the right window. 

- Double-click *Erase* to clear both text windows.
