Audio adjust

* Added Tx/Rx audio adjustment details

fldigi_doxygen/user_src_docs/Doxyfile

@@ -42,6 +42,7 @@ INPUT                = index.txt \
 	fldigi_macros.txt fldigi_modems.txt fldigi_operating.txt \
 	fldigi_developer.txt \
 	New-Install.txt thumb_drive.txt colorsandfonts.txt \
+	audio-adjust.txt \
 	configcallsigndb.txt configContestia.txt configCW.txt \
 	configDomEX.txt configFH.txt \
 	configFSQ.txt configIFKP.txt \
@@ -58,7 +59,7 @@ INPUT                = index.txt \
 	DominoEX.txt hell.txt Contestia.txt MFSK.txt MT63.txt \
 	FSQ.txt IFKP.txt \
 	Navtex.txt psk.txt Olivia.txt RTTYFSK.txt Thor.txt \
-	throb.txt tune.txt WEFAX.txt WWV-xmt.txt FrequencyAnalysis.txt \
+	throb.txt WEFAX.txt WWV-xmt.txt FrequencyAnalysis.txt \
 	DigiscopeDisplay.txt DigiWWV.txt MousingKeyboardShortcuts.txt \
 	Multiples.txt Notifier.txt OperatingControls.txt RST-RSQ.txt \
 	Spotter.txt Synop.txt TransceiverControl.txt UTF8.txt \

fldigi_doxygen/user_src_docs/Menus.txt

@@ -538,7 +538,7 @@ See \ref configuration_page Page
 	<li>Tune button - toggles the "Tune" mode which causes fldigi to
 	insert a tone at the current waterfall frequency.  The peak-to-peak
 	amplitude of this tone is the standard by which you should
-	\ref tune_page "set your transmitter drive" or adjust your antenna
+	\ref audio_adjust_page "set your transmitter drive" or adjust your antenna
 	matching network.</li>
 	<li>The right most button is normally not visible.  This is the
 	count-down timer button that is enabled when a macro button has been

fldigi_doxygen/user_src_docs/audio-adjust.txt

@@ -0,0 +1,188 @@
+/**
+\page audio_adjust_page RX/TX Audio Adjustment
+
+\tableofcontents
+
+\section rx_audio Receive audio
+
+Setting the correct hardware, operating system, and fldigi received audio
+levels is not difficult, but it is the one setup procedure most often done
+incorrectly.  The most commonly used sound card devices contain either a
+16 or 24 bit analog to digital (a/d) converter.  A 16 bit a/d can provide
+approximately 90 db of signal conversion.  For the 16 bit converter, if the 
+peak audio signal that the a/d can handle is +/- 1 volt then the minimum 
+discernable signal (1 bit) will be +/- 30.5 microvolts.  If more than a +/- 1 volt
+signal is applied to the a/d input then either one of two things may occur,
+(1) the audio is clipped, or (2) the audio is wrapped, large positive signals
+wrap to large negative signals and vice versa.
+
+The objective in adjusting the Rx audio is to use the full dynamic range of the
+a/d without incurring overdrive.  fldigi provides a number of display controls to
+assist in setting up the Rx audio.  There are two controls that ONLY adjust the
+visual appearance of the waterfall and DO NOT effect the a/d or the signal decoders.
+These controls are below and to the left of the waterfall, "Upper signal level (dB)", and
+"Signal range (dB)".
+
+<center>
+\image html win10-fldigi-wf-adjust.png "Waterfall level/range controls"
+\image latex win10-fldigi-wf-adjust.png "Waterfall level/range controls" width=1.5in
+</center>
+
+Change the waterfall display to the "Scope" view.  Do this by pressing the "WF" button twice if
+it is currently displaying the waterfall.  You can also right click once on that button.  That
+button acts as a rotary and is left/right click sensitive.  The display should show what looks 
+like an oscilloscope view of the received audio.  This is the entire audio signal and not just 
+the signal that is currently decoded.
+
+<center>
+\image html win10-fldigi-signal.png "Scope view"
+\image latex win10-fldigi-signal.png "Scope view" width=1.5in
+</center>
+
+If your sound card a/d (also referred to as codec) is functioning correctly there
+should be no signal offset and the signal will be centered vertically about the y-axis.  Set your
+transceiver to a portion of the band with digital signals, 14.070 MHz is a good spot.  Now adjust
+the transceiver audio output and the operating system mixer controls so that the peak signals do
+not exceed the upper/lower gray lines on the display.  The diamond indicator to the left of the 
+fldigi AFC button will be colored as follows:
+<ul>
+<li>BLACK - no signal, or insufficient Rx audio</li>
+<li>GREEN - signals are in the correct range</li>
+<li>YELLOW - signals are exceed 75% of maximum, but are less than 90% of maximum</li>
+<li>RED - signals exceed 90% of maximum a/d capability - WARNING WILL ROBINSON!</li>
+</ul>
+You can then proceed to adjust the waterfall/fft appearance when you have the audio Rx level adjusted correctly.
+
+The three signal views should be similar to this with the level/range controls set to 0 and 60 respectively.  The 
+waterfall palette used is "default.pal", and the received signal is about 20 dB above the noise floor.
+<center>
+<table>
+  <tr>
+    <td>
+      \image html win10-fldigi-wf.png "Waterfall"
+      \image latex win10-fldigi-wf.png "Waterfal" width=1.5in
+    </td>
+    <td>
+      \image html win10-fldigi-fft.png "FFT"
+      \image latex win10-fldigi-fft.png "FFT" width=1.5in
+    </td>
+    <td>
+      \image html win10-fldigi-signal.png "Scope"
+      \image latex win10-fldigi-signal.png "Scope" width=1.5in
+    </td>
+  </tr>
+</table>
+</center>
+\section rx_win10 Windows Audio Properties
+A combination of the Windows operating system and certain audio codecs needs to be accommodated.  The codecs
+used by devices like the SignaLink-USB, the TS590S, and recent Icom transceivers are identified by the
+Windows operating system as "microphone" devices.  The Windows mixer controls for that device
+are then set to insert about 30 dB of gain in the signal path.  To compensate most users simply lower the
+transceiver audio output.  The result is very poor decoding.  The correct procedure is to force the Windows
+mixer controls to remove that 30 dB of gain.  This procedure is for Windows 10, but is similar on Windows 7,
+and Windows 8.
+
+Right click on the task bar speaker icon and select the "Recording devices" menu item.  This will open the 
+Sound devices dialog:
+<center>
+\image html win10-rec-properties.png "Sound Devices"
+\image latex win10-rec-properties.png "Sound Devices" width=3.5in
+</center>
+This is the dialog on my Windows 10 test computer with a SignaLink-USB connected to a USB hub.  The 
+SignaLink-USB shows up as a <b>Microphone</b> USB Audio CODEC.  Right click on the device entry and
+select Properties.  This opens up the Microphone Properties dialog:
+<center>
+\image html win10-mic-properties.png "Microphone Properties"
+\image latex win10-mic-properties.png "Microphone Properties" width=3.5in
+</center>
+Select the "Levels" tab and set the level to as close to 0 dB as is available:
+<center>
+\image html win10-mic-levels.png "Microphone Level"
+\image latex win10-mic-levels.png "Microphone Level" width=3.5in
+</center>
+Then select the "Advanced" tab and change the type of converter.
+<center>
+\image html win10-mic-advanced.png "Microphone Advanced Tab"
+\image latex win10-mic-advanced.png "Microphone Advanced Tab" width=3.5in
+</center>
+Apply and save the changes.  The last step is
+usually needed to insure that the settings are not lost when the operating system is closed and restarted.
+
+
+\section tx_audio Transmit audio
+
+Too often you see an overdriven signals on the digital sub-bands;
+multiple audio sidebands on PSK, splatter from overdriven MFSK and
+RTTY. There is absolutely no reason for a transceiver driven
+by fldigi to exhibit this type of performance. You can set up
+your computer / transceiver for good solid performance without excessive
+drive.
+<br>
+
+The "TUNE" button generates a continuous single frequency audio signal
+at the exact frequency to which the waterfall cursor has been set. The peak
+amplitude of this signal is the peak amplitude of every modem signal
+generated by fldigi. None will exceed this value, even the simultaneous
+multi-tone modes like Throb. Every modern SSB transmitter uses some automatic
+level control ALC for preventing overdrive for SSB voice. A little overdrive
+on a voice channel can be tolerated to a degree. In fact, that is what
+an analog RF compressor does, overdrive and then subsequent filtering.
+But you absolutely cannot tolerate that with the digital modes. Here is the
+way to set up your transceiver for a clean signal. I recommend starting out
+with a dummy load, but an "off hour" for a band might work just as well if
+you do not have a dummy load.
+<br>
+
+<ul>
+	<li>For Windows users</li>
+	<ul>
+		<li>Set your sound card output level to the minimum on the Windows
+			mixer</li>
+	</ul>
+	<li>For Linux users</li>
+	<ul>
+		<li>Set your PCM level to about 80%</li>
+		<li>Set your Transmit Level control for minimum output level.</li>
+	</ul>
+	<li>Set the fldigi transmit attenuator to -3 dB (control to the left of the AFC button)</li>
+	<li>Set the waterfall cursor to 1000 Hz</li>
+	<li>Enable the "Tune" mode in fldigi ... you do have CAT or PTT set up ...right?</li>
+	<li>Make sure your transceiver's speech compression control is OFF</li>
+	<li>Slowly bring up the Mixer audio out until your rig's ALC just starts
+		to function (a light blinking or a meter showing this condition).</li>
+	<li>Reduce the Mixer audio output until the ALC is disabled.</li>
+	<li>You are now transmitting at maximum output power without distortion.</li>
+	<li>You can use the fldigi transmit attenuator to make small adjustments 
+	in the output power to compensate for variations in the SSB transmit filter.</li>
+</ul>
+
+You can use any level below this and be assured that your output signal
+will be clean. All digital signals that fldigi generates will be limited to
+this peak-to-peak voltage. You should always use the minimum power necessary
+to maintain good comms, remember that even if you are clean at 100 W you
+signal will be so strong among the QRP signals that it will overpower the
+AGC on many receivers that are working another digital station within the
+same SSB bandwidth that you are on. You will appreciate this the first
+time that you are working a weak PSK DX station and someone blasts through
+and captures your AGC.
+<br>
+
+You should try the the above adjustments at different audio
+frequencies. Transceivers that achieve the SSB filtering with crystal or
+mechanical filters will have a considerable amount of variation across the
+passband of the filter. This will show up as a varying amount of ALC that is
+dependent on the audio frequency. Once you are comfortable with the process
+you can very quickly repeat the "Tune" and set the power for the frequency
+to which the waterfall is set.  The fldigi transmit attenuator control should
+have sufficient range to compensate for transmit SSB filter variation.  You
+do not want to transmit (or receive) near the cutoff frequencies of the SSB
+filter.  The transceiver filter will introduce both phase and amplitude 
+distortion over the signal bandwidth.
+<br>
+
+\ref tune_page "Return to Top of Page"
+<br>
+\ref main_page "Return to Main Page"
+
+
+*/

fldigi_doxygen/user_src_docs/fldigi_configuration.txt

@@ -23,6 +23,7 @@ You should initially configure the following:
 	<li> \subpage operator_configuration_page </li>
 	<li> \subpage sound_card_configuration_page </li>
 	<li> \subpage rig_control_page </li>
+	<li> \subpage audio_adjust_page </li>
 	<li> \subpage new_installation_page </li>
 	<li> \subpage config_io_page </li>
 </ul>

fldigi_doxygen/user_src_docs/fldigi_modems.txt

@@ -17,7 +17,6 @@
 	<li> \subpage rtty_page </li>
 	<li> \subpage thor_page </li>
 	<li> \subpage throb_page </li>
-	<li> \subpage tune_page </li>
 	<li> \subpage wefax_page </li>
 	<li> \subpage wwv_tx_mode </li>
 	<li> \subpage mode_table_page </li>

fldigi_doxygen/user_src_docs/index_order.txt

@@ -1,6 +1,7 @@
 fldigi_configuration.txt fldigi_developer.txt fldigi_logging.txt \
 fldigi_macros.txt fldigi_modems.txt fldigi_operating.txt \
 New-Install.txt thumb_drive.txt colorsandfonts.txt \
+audio-adjust.txt \
 configcallsigndb.txt configContestia.txt configCW.txt \
 configDomEX.txt configFSQ.txt configFH.txt ConfigID.txt \
 configIFKP.txt ConfigMisc.txt \
@@ -14,7 +15,7 @@ InlineMacroTags.txt atMacroTags.txt advanced_qsy.txt execmacro.txt CW.txt \
 DominoEX.txt hell.txt Contestia.txt MFSK.txt MT63.txt \
 FSQ.txt IFKP.txt \
 Navtex.txt psk.txt Olivia.txt RTTYFSK.txt Thor.txt \
-throb.txt tune.txt WEFAX.txt WWV-xmt.txt FrequencyAnalysis.txt \
+throb.txt WEFAX.txt WWV-xmt.txt FrequencyAnalysis.txt \
 DigiscopeDisplay.txt DigiWWV.txt map.txt MousingKeyboardShortcuts.txt \
 Multiples.txt Notifier.txt OperatingControls.txt RST-RSQ.txt \
 Spotter.txt Synop.txt TransceiverControl.txt UTF8.txt \

fldigi_doxygen/user_src_docs/psk.txt

@@ -183,7 +183,7 @@ better decoding than CW.
 
 Setting up for a good clean on air signal that will receive the accolades
 of your QSO partners is easy. Follow the instructions on using the
-\ref tune_page "Tune" button</a> and you will have a clean on signal.
+\ref audio_adjust_page "Tune" button</a> and you will have a clean on signal.
 <br>
 
 Good reception of PSK signals requires that the demodulator be phase locked

fldigi_doxygen/user_src_docs/tune.txt

@@ -1,74 +0,0 @@
-/**
-\page tune_page TUNE - Transmit a single tone carrier.
-
-\tableofcontents
-
-\section tune TUNE Mode
-
-Too often you see an overdriven signals on the digital sub-bands;
-multiple audio sidebands on PSK, splatter from overdriven MFSK and
-RTTY. There is absolutely no reason for a transceiver driven
-by fldigi to exhibit this type of performance. You can set up
-your computer / transceiver for good solid performance without excessive
-drive.
-<br>
-
-The "TUNE" button generates a continuous single frequency audio signal
-at the exact frequency to which the waterfall cursor has been set. The peak
-amplitude of this signal is the peak amplitude of every modem signal
-generated by fldigi. None will exceed this value, even the simultaneous
-multi-tone modes like Throb. Every modern SSB transmitter uses some automatic
-level control ALC for preventing overdrive for SSB voice. A little overdrive
-on a voice channel can be tolerated to a degree. In fact, that is what
-an analog RF compressor does, overdrive and then subsequent filtering.
-But you absolutely cannot tolerate that with the digital modes. Here is the
-way to set up your transceiver for a clean signal. I recommend starting out
-with a dummy load, but an "off hour" for a band might work just as well if
-you do not have a dummy load.
-<br>
-
-<ul>
-	<li>For Windows users</li>
-	<ul>
-		<li>Set your sound card output level to the minimum on the Windows
-			mixer</li>
-	</ul>
-	<li>For Linux users</li>
-	<ul>
-		<li>Set your PCM level to about 80%</li>
-		<li>Set your Transmit Level control for minimum output level.</li>
-	</ul>
-	<li>Enable the "Tune" mode in fldigi ... you do have CAT or PTT set up ...right?</li>
-	<li>Make sure your transceiver's speech compression control is OFF</li>
-	<li>Slowly bring up the Mixer audio out until your rig's ALC just starts
-		to function (a light blinking or a meter showing this condition).</li>
-	<li>Reduce the Mixer audio output until the ALC is disabled.</li>
-	<li>You are now transmitting at maximum output power without distortion.</li>
-</ul>
-
-You can use any level below this and be assured that your output signal
-will be clean. All digital signals that fldigi generates will be limited to
-this peak-to-peak voltage. You should always use the minimum power necessary
-to maintain good comms, remember that even if you are clean at 100 W you
-signal will be so strong among the QRP signals that it will overpower the
-AGC on many receivers that are working another digital station within the
-same SSB bandwidth that you are on. You will appreciate this the first
-time that you are working a weak PSK DX station and someone blasts through
-and captures your AGC.
-<br>
-
-You should try the the above adjustments at different audio
-frequencies. Transceivers that achieve the SSB filtering with crystal or
-mechanical filters will have a considerable amount of variation across the
-passband of the filter. This will show up as a varying amount of ALC that is
-dependent on the audio frequency. Once you are comfortable with the process
-you can very quickly repeat the "Tune" and set the power for the frequency
-to which the waterfall is set.
-<br>
-
-\ref tune_page "Return to Top of Page"
-<br>
-\ref main_page "Return to Main Page"
-
-
-*/