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<h1><span style="font-weight: bold;">Operating Controls & Displays</span></h1>
</div>
<span style="font-weight: bold;"><br>
</span>
<div style="text-align: center;"><span style="font-weight: bold;"><img style="width: 743px; height: 182px;" alt="" src="images/fldigi-controls.png"></span><br>
<span style="font-weight: bold;"></span></div>
<span style="font-weight: bold;">
<span style="font-weight: bold;"><span style="font-weight: bold;"><span style="font-weight: bold;"><br>
<span style="font-weight: bold;"><span style="font-weight: bold;"></span></span></span></span></span></span>The
main display for fldigi is the waterfall display shown above in color
and in scale x1. The above display shows fldigi configured by invoking the following command line switches:<br>
<br>
<div style="margin-left: 40px;">fldigi -bg2 black -fg white -bg
grey40 --wfall-height 150
--wfall-width 3000 --font sans:12<br><br>
The macro button colors are set to the default on the colors-fonts dialog.<br><br>You
don't have to remember all of those switch settings every time you
start fldigi. Just enter them on the Command Line, Launcher tab
for the desktop icon properties (Gnome desktop).<br><br>Or
from Windows XP on the Target Line, of the Shortcut tab for the
properties dialog associated with the fldigi desktop icon. The
fg, bg and bg2 specification on Windows is not the same as Linux.
On Windows those three <a href="CommandLine.html">command line parameters</a> need to be:<br><br><div style="margin-left: 40px;">-bg2 FFFFFF -fg 000000 -bg 606060<br><br></div>where each color is specified by its RRGGBB component as a hexadecimal value.</div>
<br>The button <span style="font-weight: bold;">Wtr</span>
toggles the display between a waterfall and a spectrum display.
This button acts as a rotary. Left clicking moves the
display selection in one direction and right clicking in the other
direction. The three display modes are <span style="font-weight: bold;">Wtr</span> - waterfall, <span style="font-weight: bold;">FFT</span> - spectrum (Fast Fourier Transform) and <span style="font-weight: bold;">Sig</span> - oscilloscope time domain. Let the mouse cursor hover over any one of the controls and a
small hint box will open to help you navigate the various controls.
<br><br>The <span style="font-weight: bold;">Norm</span>
button controls the
speed of the waterfall drop. This is also a rotary type of
button control. The speeds available are SLOW, NORM, FAST
and PAUSE. The load on the cpu will be directly proportional to
this
selection. If your cpu is slow you might want to select the SLOW
or PAUSE
option for the waterfall.<br>
<br>
The scale control (X1, X2, X4) expands or contracts the view into the
fast fourier transform that is displayed on the waterfall or the FFT
display. fldigi always computes the FFT to a 1 Hz resolution, and
displays the results according to the scale control.<br>
<br>
<table style="width: 75%; text-align: left; margin-left: auto; margin-right: auto;" border="0" cellpadding="4" cellspacing="2">
<tbody>
<tr>
<td style="text-align: center;"><img style="width: 181px; height: 114px;" alt="" src="images/psk-waterfallx1.png" hspace="5"></td>
<td style="text-align: center;"><img style="width: 252px; height: 118px;" alt="" src="images/psk-waterfallx2.png" hspace="5"></td>
<td style="text-align: center;"><img style="width: 301px; height: 116px;" alt="" src="images/psk-waterfallx4.png" hspace="5"></td>
</tr>
<tr>
<td style="text-align: center;">X1 scale</td>
<td style="text-align: center;">X2 scale</td>
<td style="text-align: center;">X4 scale</td>
</tr>
</tbody>
</table>
<br>
The
next three controls are positional conrols for the waterfall. The
waterfall can display 4096 data points, where each one can be thought
of as a spectral line at the equivalent Hertz. The ratio is
actually
8000/8192 and is related to the ratio of sound card sampling rate to
Fast Fourier Transform length. This ratio changes for some modems
that
require a sampling rate other than 8000 Hz. The left arrow key
will
shift the display to the right (displays a lower section of the
spectrum). The right arrow key moves the display higher in
frequency.
These two buttons are repeating buttons. Hold them down and
the
display slews at about 20 shifts / sec. The center button with
the two
vertical block lines is a "center the signal" button. The current
cursor (red signal cursor in the waterfall) will be centered in the
display area. NOTE: these controls are only functional if
the current waterfall or spectrum view is smaller than the full view
available. This is usually the case when the X2 or X4 expansion
is selected. But it also might be the case when the width of the
main dialog is reduced so that the waterfall display does not extend
over the entire available width.<br>
<br>
Try moving the cursor around in the waterfall
area. You will see a set of yellow cursor blocks that show the center
point and bandwidth of the current operating mode (psk31 = 31.25 Hz for
example). To capture a received signal just click near the signal and
the AFC will perform a multi-step acquisition. This will be very fast
and should not require additional operator intervention. <span style="font-weight: bold; font-style: italic;">Casual tuning</span>
You can take a look at any received signal on the waterfall by
right-clicking and holding the mouse button on or near the signal.
The modem will begin to decode that signal if it is in the
currently selected mode. The text will be a unique color on the
Rx text widget so that you can discern the difference between casual
and normal tracking. Release the mouse button and the tracking
returns to the previously selected normal tracking point.<br>
<br>
<span style="font-weight: bold;">Audio History</span> Fldigi maintains
a history buffer of the received audio. This buffer is
approximately 2 minutes in duration. After tracking commences on
a signal you can decode the audio history for that signal. The
audio history is invoked by a Ctrl-Left click anywhere on the
waterfall. You can also invoke the audio history for the casual
tuning mode by pressing Ctrl-Right click on the waterfall.<br>
<br>
The
next control is your transceive audio frequency. In the display above
you can see that the audio signal is 1679 Hz. The red cursor is
centered beneath 14071.679 Mhz. The transceiver was set to 14070 Mhz. The
arrow key pairs move up/down in cycles and tens of cycles. You can
fine tune the receive point using this control.<br>
<br>
The next two
controls to the right of the audio frequency control are for the
receive signal processing. The one that reads -10 is the max
signal
level for the waterfall/spectrum display. The one that reads 51
is for
the range over which that control will display signals. Both of
these
are in dB. The default of -10 / 40 is a good starting point, but
you
need to adjust these for band conditions. You can see the impact
of
these controls most easily by putting the main display area in the
spectrum mode. Changes in these controls will effect the
waterfall instantly and for all past history displayed on the
waterfall. You do not have to wait for new signal data to observe
the effect.<br>
<br>
<a name="QSY"></a>
The <span style="font-weight: bold;">QSY</span> button is very specific to rigs
interfaced with either hamlib or the memory mapped i/o. Each rig has a
sweet spot associated with its bandwidth controller. For the Argonaut
V this is 1100 Hz. For the the Kachina it is 1000 Hz. As the
transceivers bandwidth is changed the changes occur centered at this
frequency. So .... let's say that I just started copying a rare dx at
1758 Hz and I wanted to put the signal at the sweet spot so I could
easily narrow the receiver bandwidth. Click on the signal on the
waterfall. Let the AFC capture and then press the QSY button. The
tranceiver frequency will be shifted and the fldigi audio tracking
point shifted in unison such that the signal is now at the receivers
sweet spot. Very fast and very convenient! If you do not have hamlib
enabled for your transceiver this button will be dimmed and not
activated.<br>
<br>
The <span style="font-weight: bold;">M></span> button allows you to
store, recall and manage mode/frequency pairs. If you want to
save the current mode and frequency simply left click the button.
A right click will enable a popup menu from which you can select
a previously stored set. You can quickly move between modes and
audio sub carrier using this technique. A shift-left click will
clear the memory. When the popup menu is visible you left click
on an entry to select it. You can shift-left click on an entry to
delete that single entry.<br>
<br>
The <span style="font-weight: bold;">T/R</span>
button should be self-explanatory. It's your transmit/receive button.
Action is immediate, so if you were transmiting some text and hit the
button the PTT is disabled, the transmit text area cleared and the
program returned to receive mode. The T/R button is a "lighted button" that shows <span style="color: rgb(204, 0, 0);">RED <span style="color: rgb(0, 0, 0);">when transmitting. All other lighted buttons show YELLOW when they are in the active state.</span></span><br>
<br>
The <span style="font-weight: bold;">Lck</span>
button locks the transmit audio frequency to its present value. You
can then continue to QSY around your transmit position. I have used this to
reply to a DX station that wanted a +500 Hz response. The DX was at
690 Hz audio, and wanted a response at +500. I moved the display
cursor (or the audio frequency control) to 1190 Hz. Hit the Lck button
and then went back to 690 with the waterfall cursor. Now the program
is receiving on 690 Hz and transmitting on 1190 Hz. Caught him on the
first try. Use this button also as a <span style="font-style: italic;">Master Station</span>
control. Not all rigs are equal in their VFO performance. Some
exhibit a shift between receive and transmit. If this occurs then the
stations find themselves chasing each other with every t/r exchange.
Locking your transmit frequency with this control will inhibit that
from happening. Be sure to disable the control when that qso is over or
<span style="font-weight: bold;">you may forget and transmit over top of another qso!<br>
<br>
</span>If the "Lck" is enabled the TX
frequency does not follow the AFC action applied to the RX frequency.<br>
<br>
For transceivers which are either hamlib or memmap enabled, if the "Qsy" button is pressed BOTH the RX and TX frequencies are
changed to synchronize to where the RX was positioned.<br>
<br>
Perhaps some numbers will help to make that a little clearer.<br>
<br>
<table style="width: 75%; text-align: left; margin-left: auto; margin-right: auto;" border="1" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td style="vertical-align: top;">"Lck"<br>
</td>
<td valign="top">Before "Qsy"<br>
</td>
<td valign="top"><br>
</td>
<td valign="top">After "Qsy"<br>
</td>
<td valign="top"><br>
</td>
</tr>
<tr>
<td valign="top"><br>
</td>
<td valign="top">RX<br>
</td>
<td valign="top">TX<br>
</td>
<td valign="top">RX<br>
</td>
<td valign="top">TX<br>
</td>
</tr>
<tr>
<td valign="top">OFF<br>
</td>
<td valign="top">1002 / 7071.002<br>
</td>
<td valign="top">1002 / 7071.002<br>
</td>
<td valign="top">1500 / 7071.002<br>
</td>
<td valign="top">1500 / 7071.002<br>
</td>
</tr>
<tr>
<td valign="top">ON<br>
</td>
<td valign="top">1002 / 7071.002<br>
</td>
<td valign="top">1000 / 7071.000<br>
</td>
<td valign="top">1500 / 7071.002<br>
</td>
<td valign="top">1500 / 7071.002<br>
</td>
</tr>
<tr>
<td valign="top">ON<br>
</td>
<td valign="top">1000 / 7071.000<br>
</td>
<td valign="top">1800 / 7071.800<br>
</td>
<td valign="top">1500 / 7071.000<br>
</td>
<td valign="top">1500 / 7071.000<br>
</td>
</tr>
</tbody>
</table>
<br>
With "Lck" off the TX audio frequency is always synchronized with the
RX frequency.<br>
<br>
With "Lck" on the TX audio frequency is fixed with respect to the RX
frequency UNLESS the "Qsy" button is pressed in which case it shifts to
the RX frequency, the Transceiver VFO is shifted and both the RX and TX
audio frequencies are shifted to put both into the middle of the
transceiver passband. The TX continues to be locked, but at the new
audio frequency.<br>
<br>
If the "Lck" is ON moving the cursor around will ONLY EFFECT the RX
frequency and NOT the TX frequency.<br>
<br>
The <span style="font-weight: bold;">AFC </span>and <span style="font-weight: bold;">SQL</span>
buttons enable or disable the respective function in the software.
The
slider just above the AFC & SQL controls is the squelch level
control.
The bar indicator just above it is the equivalent of received
signal
level and relates on a 1:1 basis with the squelch level slider.
The SQL button illuminates YELLOW when the SQL is selected, but
the signal is below the squelch level. It illuminates GREEN when
the the SQL is selected and the signal is above the squelch level.<br>
<br>
The indicator just to the left of the AFC button is the overload
indicator. It will be GREEN if your audio drive to sound card is satisfactory, YELLOW if the audio signal is
marginally high and turn red when it is in overload. Back
down the mixer control or the audio pad from the rig to computer.
Fldigi will not perform well if the sound card is over driven.
You will see ghost signals on the waterfall and the modem
decoders will not work correctly.<br><br>
Receive audio level should be adjusted so that the overload indicator does not illuminate red. When
observing the received signals on the oscilloscope view you should
expect that they do not exceed a peak-to-peak amplitude of 3/4 of the
full display height.<br><h3>Mode Status Indicators</h3>The
lower left corner of the main display (MFSK-16) in the view above is
actually a button disquised as a status panel. This button
responds to the mouse in several ways:<br><ul><li>Left Click - opens a quick pick list of associated modem types; you can switch to a new modem type from this popup menu</li><li>Right Click - opens the configuration dialog at the tab associated with the current modem type</li><li>Scroll
Wheel - rotates forward and backwards through the various modem types
in accordanced with the modem menu heirarchy. Stop at the one you
want and you are now in that mode</li></ul>The next status indicator to
the right provides information relative to the current modem, for PSK
it indicates the received signal strength in dB.<br>The third status
indicator from the left provides additional information relative to the
current modem, IMD for PSK measured in dB.<br>Note that for PSK these values are only measured during periods when the PSK idle signal is being received.<br><div style="text-align: center;"><a href="index.html">Contents</a><br></div>
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