Make the low cutoff frequency of the SSB filter variable. Change spectrum overlay accordingly.

Readme.md

@@ -78,7 +78,8 @@ Done since the fork
   - SSB bandwidth can now be tuned in steps of 100 Hz
   - NFM and SSB receiver in focus trigger the display of the central frequency line on the spectrum frequency scale thus facilitating its identification
   - Added AM demod so now you can listen to air traffic!
-  - Added the possibility to change the brightness and/or color of the grid. 
+  - Added the possibility to change the brightness and/or color of the grid.
+  - Make the low cutoff frequency of the SSB filter variable so it can be used for CW also.
     
 =====
 To Do

include-gpl/gui/glspectrum.h

@@ -54,11 +54,13 @@ private:
 	struct ChannelMarkerState {
 		ChannelMarker* m_channelMarker;
 		QRectF m_glRect;
+		QRectF m_glRectDsb;
 		QRect m_rect;
 
 		ChannelMarkerState(ChannelMarker* channelMarker) :
 			m_channelMarker(channelMarker),
-			m_glRect()
+			m_glRect(),
+			m_glRectDsb()
 		{ }
 	};
 	QList<ChannelMarkerState*> m_channelMarkerStates;
@@ -150,8 +152,6 @@ private:
 	void enterEvent(QEvent* event);
 	void leaveEvent(QEvent* event);
 
-	float getCenterFreqLineRelPos(ChannelMarker *channelMarker);
-
 private slots:
 	void tick();
 	void channelMarkerChanged();

include/dsp/channelmarker.h

@@ -27,6 +27,9 @@ public:
 	void setBandwidth(int bandwidth);
 	int getBandwidth() const { return m_bandwidth; }
 
+	void setLowCutoff(int lowCutoff);
+	int getLowCutoff() const { return m_lowCutoff; }
+
 	void setSidebands(sidebands_t sidebands);
 	sidebands_t getSidebands() const { return m_sidebands; }
 
@@ -46,6 +49,7 @@ protected:
 	QString m_title;
 	int m_centerFrequency;
 	int m_bandwidth;
+	int m_lowCutoff;
 	sidebands_t m_sidebands;
 	bool m_visible;
 	bool m_highlighted;

plugins/channel/ssb/ssbdemod.cpp

@@ -22,6 +22,8 @@
 #include "audio/audiooutput.h"
 #include "dsp/dspcommands.h"
 
+#include <iostream>
+
 MESSAGE_CLASS_DEFINITION(SSBDemod::MsgConfigureSSBDemod, Message)
 
 SSBDemod::SSBDemod(AudioFifo* audioFifo, SampleSink* sampleSink) :
@@ -29,6 +31,7 @@ SSBDemod::SSBDemod(AudioFifo* audioFifo, SampleSink* sampleSink) :
 	m_audioFifo(audioFifo)
 {
 	m_Bandwidth = 5000;
+	m_LowCutoff = 300;
 	m_volume = 2.0;
 	m_sampleRate = 96000;
 	m_frequency = 0;
@@ -41,7 +44,7 @@ SSBDemod::SSBDemod(AudioFifo* audioFifo, SampleSink* sampleSink) :
 	m_undersampleCount = 0;
 
 	m_usb = true;
-	SSBFilter = new fftfilt(0.01, m_Bandwidth / 48000.0, ssbFftLen);
+	SSBFilter = new fftfilt(m_LowCutoff / 48000.0, m_Bandwidth / 48000.0, ssbFftLen);
 	// if (!USBFilter) segfault;
 }
 
@@ -50,9 +53,9 @@ SSBDemod::~SSBDemod()
 	if (SSBFilter) delete SSBFilter;
 }
 
-void SSBDemod::configure(MessageQueue* messageQueue, Real Bandwidth, Real volume)
+void SSBDemod::configure(MessageQueue* messageQueue, Real Bandwidth, Real LowCutoff, Real volume)
 {
-	Message* cmd = MsgConfigureSSBDemod::create(Bandwidth, volume);
+	Message* cmd = MsgConfigureSSBDemod::create(Bandwidth, LowCutoff, volume);
 	cmd->submit(messageQueue, this);
 }
 
@@ -110,7 +113,7 @@ void SSBDemod::stop()
 
 bool SSBDemod::handleMessage(Message* cmd)
 {
-	float band;
+	float band, lowCutoff;
 
 	if(DSPSignalNotification::match(cmd)) {
 		DSPSignalNotification* signal = (DSPSignalNotification*)cmd;
@@ -125,17 +128,26 @@ bool SSBDemod::handleMessage(Message* cmd)
 		MsgConfigureSSBDemod* cfg = (MsgConfigureSSBDemod*)cmd;
 
 		band = cfg->getBandwidth();
+		lowCutoff = cfg->getLoCutoff();
+
 		if (band < 0) {
 			band = -band;
+			lowCutoff = -lowCutoff;
 			m_usb = false;
 		} else
 			m_usb = true;
-		if (band < 500.0f)
+
-			band = 500.0f;
+		if (band < 100.0f)
+		{
+			band = 100.0f;
+			lowCutoff = 0;
+		}
+
 		m_Bandwidth = band;
+		m_LowCutoff = lowCutoff;
 
 		m_interpolator.create(16, m_sampleRate, band * 2.0f);
-		SSBFilter->create_filter(0.3f / 48.0f, m_Bandwidth / 48000.0f);
+		SSBFilter->create_filter(m_LowCutoff / 48000.0f, m_Bandwidth / 48000.0f);
 
 		m_volume = cfg->getVolume();
 		m_volume *= m_volume * 0.1;

plugins/channel/ssb/ssbdemod.h

@@ -35,7 +35,7 @@ public:
 	SSBDemod(AudioFifo* audioFifo, SampleSink* sampleSink);
 	~SSBDemod();
 
-	void configure(MessageQueue* messageQueue, Real Bandwidth, Real volume);
+	void configure(MessageQueue* messageQueue, Real Bandwidth, Real LowCutoff, Real volume);
 
 	void feed(SampleVector::const_iterator begin, SampleVector::const_iterator end, bool positiveOnly);
 	void start();
@@ -48,20 +48,23 @@ private:
 
 	public:
 		Real getBandwidth() const { return m_Bandwidth; }
+		Real getLoCutoff() const { return m_LowCutoff; }
 		Real getVolume() const { return m_volume; }
 
-		static MsgConfigureSSBDemod* create(Real Bandwidth, Real volume)
+		static MsgConfigureSSBDemod* create(Real Bandwidth, Real LowCutoff, Real volume)
 		{
-			return new MsgConfigureSSBDemod(Bandwidth, volume);
+			return new MsgConfigureSSBDemod(Bandwidth, LowCutoff, volume);
 		}
 
 	private:
 		Real m_Bandwidth;
+		Real m_LowCutoff;
 		Real m_volume;
 
-		MsgConfigureSSBDemod(Real Bandwidth, Real volume) :
+		MsgConfigureSSBDemod(Real Bandwidth, Real LowCutoff, Real volume) :
 			Message(),
 			m_Bandwidth(Bandwidth),
+			m_LowCutoff(LowCutoff),
 			m_volume(volume)
 		{ }
 	};
@@ -73,6 +76,7 @@ private:
 	typedef std::vector<AudioSample> AudioVector;
 
 	Real m_Bandwidth;
+	Real m_LowCutoff;
 	Real m_volume;
 	int m_undersampleCount;
 	int m_sampleRate;

plugins/channel/ssb/ssbdemodgui.cpp

@@ -13,6 +13,8 @@
 #include "util/simpleserializer.h"
 #include "gui/basicchannelsettingswidget.h"
 
+#include <iostream>
+
 SSBDemodGUI* SSBDemodGUI::create(PluginAPI* pluginAPI)
 {
 	SSBDemodGUI* gui = new SSBDemodGUI(pluginAPI);
@@ -42,6 +44,7 @@ QByteArray SSBDemodGUI::serialize() const
 	SimpleSerializer s(1);
 	s.writeS32(1, m_channelMarker->getCenterFrequency());
 	s.writeS32(2, ui->BW->value());
+	s.writeS32(6, ui->lowCut->value());
 	s.writeS32(3, ui->volume->value());
 	s.writeBlob(4, ui->spectrumGUI->serialize());
 	s.writeU32(5, m_channelMarker->getColor().rgb());
@@ -63,8 +66,10 @@ bool SSBDemodGUI::deserialize(const QByteArray& data)
 		qint32 tmp;
 		d.readS32(1, &tmp, 0);
 		m_channelMarker->setCenterFrequency(tmp);
-		d.readS32(2, &tmp, 3);
+		d.readS32(2, &tmp, 30);
 		ui->BW->setValue(tmp);
+		d.readS32(6, &tmp, 3);
+		ui->lowCut->setValue(tmp);
 		d.readS32(3, &tmp, 20);
 		ui->volume->setValue(tmp);
 		d.readBlob(4, &bytetmp);
@@ -114,11 +119,48 @@ void SSBDemodGUI::on_BW_valueChanged(int value)
 	QString s = QString::number(value/10.0, 'f', 1);
 	ui->BWText->setText(s);
 	m_channelMarker->setBandwidth(value * 100 * 2);
+
 	if (value < 0) {
 		m_channelMarker->setSidebands(ChannelMarker::lsb);
 	} else {
 		m_channelMarker->setSidebands(ChannelMarker::usb);
 	}
+
+	on_lowCut_valueChanged(m_channelMarker->getLowCutoff()/100);
+}
+
+int SSBDemodGUI::getEffectiveLowCutoff(int lowCutoff)
+{
+	int ssbBW = m_channelMarker->getBandwidth() / 2;
+	int effectiveLowCutoff = lowCutoff;
+	const int guard = 100;
+
+	if (ssbBW < 0) {
+		if (effectiveLowCutoff < ssbBW + guard) {
+			effectiveLowCutoff = ssbBW + guard;
+		}
+		if (effectiveLowCutoff > 0)	{
+			effectiveLowCutoff = 0;
+		}
+	} else {
+		if (effectiveLowCutoff > ssbBW - guard)	{
+			effectiveLowCutoff = ssbBW - guard;
+		}
+		if (effectiveLowCutoff < 0)	{
+			effectiveLowCutoff = 0;
+		}
+	}
+
+	return effectiveLowCutoff;
+}
+
+void SSBDemodGUI::on_lowCut_valueChanged(int value)
+{
+	int lowCutoff = getEffectiveLowCutoff(value * 100);
+	m_channelMarker->setLowCutoff(lowCutoff);
+	QString s = QString::number(lowCutoff/1000.0, 'f', 1);
+	ui->lowCutText->setText(s);
+	ui->lowCut->setValue(lowCutoff/100);
 	applySettings();
 }
 
@@ -207,6 +249,7 @@ void SSBDemodGUI::applySettings()
 		m_channelMarker->getCenterFrequency());
 	m_ssbDemod->configure(m_threadedSampleSink->getMessageQueue(),
 		ui->BW->value() * 100.0,
+		ui->lowCut->value() * 100.0,
 		ui->volume->value() / 10.0 );
 }
 

plugins/channel/ssb/ssbdemodgui.h

@@ -37,6 +37,7 @@ private slots:
 	void on_deltaFrequency_changed(quint64 value);
 	void on_deltaMinus_clicked(bool minus);
 	void on_BW_valueChanged(int value);
+	void on_lowCut_valueChanged(int value);
 	void on_volume_valueChanged(int value);
 	void onWidgetRolled(QWidget* widget, bool rollDown);
 	void onMenuDoubleClicked();
@@ -56,6 +57,7 @@ private:
 	explicit SSBDemodGUI(PluginAPI* pluginAPI, QWidget* parent = NULL);
 	~SSBDemodGUI();
 
+	int  getEffectiveLowCutoff(int lowCutoff);
 	void applySettings();
 
 	void leaveEvent(QEvent*);

plugins/channel/ssb/ssbdemodgui.ui

@@ -41,6 +41,41 @@
     <property name="spacing">
      <number>3</number>
     </property>
+    <item row="1" column="1">
+     <widget class="QSlider" name="BW">
+      <property name="minimum">
+       <number>-60</number>
+      </property>
+      <property name="maximum">
+       <number>60</number>
+      </property>
+      <property name="pageStep">
+       <number>1</number>
+      </property>
+      <property name="value">
+       <number>30</number>
+      </property>
+      <property name="orientation">
+       <enum>Qt::Horizontal</enum>
+      </property>
+     </widget>
+    </item>
+    <item row="3" column="2">
+     <widget class="QLabel" name="volumeText">
+      <property name="minimumSize">
+       <size>
+        <width>50</width>
+        <height>0</height>
+       </size>
+      </property>
+      <property name="text">
+       <string>2.0</string>
+      </property>
+      <property name="alignment">
+       <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+      </property>
+     </widget>
+    </item>
     <item row="1" column="2">
      <widget class="QLabel" name="BWText">
       <property name="minimumSize">
@@ -57,7 +92,7 @@
       </property>
      </widget>
     </item>
-    <item row="2" column="1">
+    <item row="3" column="1">
      <widget class="QSlider" name="volume">
       <property name="maximum">
        <number>100</number>
@@ -70,65 +105,6 @@
       </property>
      </widget>
     </item>
-    <item row="1" column="1">
-     <widget class="QSlider" name="BW">
-      <property name="minimum">
-       <number>-60</number>
-      </property>
-      <property name="maximum">
-       <number>60</number>
-      </property>
-      <property name="pageStep">
-       <number>10</number>
-      </property>
-      <property name="value">
-       <number>30</number>
-      </property>
-      <property name="orientation">
-       <enum>Qt::Horizontal</enum>
-      </property>
-     </widget>
-    </item>
-    <item row="2" column="0">
-     <widget class="QLabel" name="label_2">
-      <property name="text">
-       <string>Volume</string>
-      </property>
-     </widget>
-    </item>
-    <item row="2" column="2">
-     <widget class="QLabel" name="volumeText">
-      <property name="minimumSize">
-       <size>
-        <width>50</width>
-        <height>0</height>
-       </size>
-      </property>
-      <property name="text">
-       <string>2.0</string>
-      </property>
-      <property name="alignment">
-       <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-      </property>
-     </widget>
-    </item>
-    <item row="1" column="0">
-     <widget class="QLabel" name="label">
-      <property name="text">
-       <string>Bandwidth</string>
-      </property>
-     </widget>
-    </item>
-    <item row="0" column="0">
-     <widget class="QRadioButton" name="deltaMinus">
-      <property name="layoutDirection">
-       <enum>Qt::RightToLeft</enum>
-      </property>
-      <property name="text">
-       <string>Minus</string>
-      </property>
-     </widget>
-    </item>
     <item row="0" column="1">
      <widget class="ValueDial" name="deltaFrequency" native="true">
       <property name="sizePolicy">
@@ -160,6 +136,20 @@
       </property>
      </widget>
     </item>
+    <item row="1" column="0">
+     <widget class="QLabel" name="BWLabel">
+      <property name="text">
+       <string>Bandwidth</string>
+      </property>
+     </widget>
+    </item>
+    <item row="3" column="0">
+     <widget class="QLabel" name="volumeLabel">
+      <property name="text">
+       <string>Volume</string>
+      </property>
+     </widget>
+    </item>
     <item row="0" column="2">
      <widget class="QLabel" name="deltaUnits">
       <property name="text">
@@ -167,6 +157,58 @@
       </property>
      </widget>
     </item>
+    <item row="0" column="0">
+     <widget class="QRadioButton" name="deltaMinus">
+      <property name="layoutDirection">
+       <enum>Qt::RightToLeft</enum>
+      </property>
+      <property name="text">
+       <string>Minus</string>
+      </property>
+     </widget>
+    </item>
+    <item row="2" column="0">
+     <widget class="QLabel" name="lowCutLabel">
+      <property name="text">
+       <string>Low cutoff</string>
+      </property>
+     </widget>
+    </item>
+    <item row="2" column="1">
+     <widget class="QSlider" name="lowCut">
+      <property name="minimum">
+       <number>-60</number>
+      </property>
+      <property name="maximum">
+       <number>60</number>
+      </property>
+      <property name="pageStep">
+       <number>1</number>
+      </property>
+      <property name="value">
+       <number>3</number>
+      </property>
+      <property name="orientation">
+       <enum>Qt::Horizontal</enum>
+      </property>
+     </widget>
+    </item>
+    <item row="2" column="2">
+     <widget class="QLabel" name="lowCutText">
+      <property name="minimumSize">
+       <size>
+        <width>50</width>
+        <height>0</height>
+       </size>
+      </property>
+      <property name="text">
+       <string>0.3 kHz</string>
+      </property>
+      <property name="alignment">
+       <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+      </property>
+     </widget>
+    </item>
    </layout>
   </widget>
   <widget class="QWidget" name="spectrumContainer" native="true">
@@ -214,18 +256,6 @@
   </widget>
  </widget>
  <customwidgets>
-  <customwidget>
-   <class>GLSpectrum</class>
-   <extends>QWidget</extends>
-   <header>gui/glspectrum.h</header>
-   <container>1</container>
-  </customwidget>
-  <customwidget>
-   <class>GLSpectrumGUI</class>
-   <extends>QWidget</extends>
-   <header>gui/glspectrumgui.h</header>
-   <container>1</container>
-  </customwidget>
   <customwidget>
    <class>RollupWidget</class>
    <extends>QWidget</extends>
@@ -238,6 +268,18 @@
    <header>gui/valuedial.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>GLSpectrum</class>
+   <extends>QWidget</extends>
+   <header>gui/glspectrum.h</header>
+   <container>1</container>
+  </customwidget>
+  <customwidget>
+   <class>GLSpectrumGUI</class>
+   <extends>QWidget</extends>
+   <header>gui/glspectrumgui.h</header>
+   <container>1</container>
+  </customwidget>
  </customwidgets>
  <resources/>
  <connections/>

sdrbase/dsp/channelmarker.cpp

@@ -1,5 +1,7 @@
 #include "dsp/channelmarker.h"
 
+#include <iostream>
+
 QRgb ChannelMarker::m_colorTable[] = {
 	qRgb(0xc0, 0x00, 0x00),
 	qRgb(0x00, 0xc0, 0x00),
@@ -29,6 +31,7 @@ ChannelMarker::ChannelMarker(QObject* parent) :
 	QObject(parent),
 	m_centerFrequency(0),
 	m_bandwidth(0),
+	m_lowCutoff(0),
 	m_sidebands(dsb),
 	m_visible(false),
 	m_highlighted(false),
@@ -57,6 +60,12 @@ void ChannelMarker::setBandwidth(int bandwidth)
 	emit changed();
 }
 
+void ChannelMarker::setLowCutoff(int lowCutoff)
+{
+	m_lowCutoff = lowCutoff;
+	emit changed();
+}
+
 void ChannelMarker::setSidebands(sidebands_t sidebands)
 {
 	m_sidebands = sidebands;

sdrbase/gui/glspectrum.cpp

@@ -551,20 +551,10 @@ void GLSpectrum::paintGL()
 
 		// paint channels
 		if(m_mouseInside) {
+			// Effective BW overlays
 			for(int i = 0; i < m_channelMarkerStates.size(); ++i) {
 				ChannelMarkerState* dv = m_channelMarkerStates[i];
 				if(dv->m_channelMarker->getVisible()) {
-					/*
-					ChannelMarker::sidebands_t sidebands = dv->m_channelMarker->getSidebands();
-					float fcLineRelativePos;
-					if (sidebands == ChannelMarker::usb) {
-						fcLineRelativePos = 0.0;
-					} else if (sidebands == ChannelMarker::lsb) {
-						fcLineRelativePos = 1.0;
-					} else {
-						fcLineRelativePos = 0.5;
-					}
-					*/
 					glEnable(GL_BLEND);
 					glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 					glColor4f(dv->m_channelMarker->getColor().redF(), dv->m_channelMarker->getColor().greenF(), dv->m_channelMarker->getColor().blueF(), 0.3f);
@@ -577,11 +567,22 @@ void GLSpectrum::paintGL()
 					glVertex2f(1, 1);
 					glVertex2f(0, 1);
 					glEnd();
+					glPopMatrix();
+				}
+			}
+
+			// Center line overlays based on DSB enveloppe
+			for(int i = 0; i < m_channelMarkerStates.size(); ++i) {
+				ChannelMarkerState* dv = m_channelMarkerStates[i];
+				if(dv->m_channelMarker->getVisible()) {
 					glDisable(GL_BLEND);
 					glColor3f(0.8f, 0.8f, 0.6f);
+					glPushMatrix();
+					glTranslatef(dv->m_glRectDsb.x(), dv->m_glRectDsb.y(), 0);
+					glScalef(dv->m_glRectDsb.width(), dv->m_glRectDsb.height(), 1);
 					glBegin(GL_LINE_LOOP);
-					glVertex2f(getCenterFreqLineRelPos(dv->m_channelMarker), 0);
+					glVertex2f(0.5, 0);
-					glVertex2f(getCenterFreqLineRelPos(dv->m_channelMarker), 1);
+					glVertex2f(0.5, 1);
 					glEnd();
 					glPopMatrix();
 				}
@@ -662,6 +663,8 @@ void GLSpectrum::paintGL()
 		glPushMatrix();
 		glTranslatef(m_glWaterfallRect.x(), m_glFrequencyScaleRect.y(), 0);
 		glScalef(m_glWaterfallRect.width(), m_glFrequencyScaleRect.height(), 1);
+
+		// Effective bandwidth overlays
 		for(int i = 0; i < m_channelMarkerStates.size(); ++i) {
 			ChannelMarkerState* dv = m_channelMarkerStates[i];
 			if(dv->m_channelMarker->getVisible()) {
@@ -677,19 +680,29 @@ void GLSpectrum::paintGL()
 				glVertex2f(1, 0.5);
 				glVertex2f(0, 0.5);
 				glEnd();
-
-				if (dv->m_channelMarker->getHighlighted()) {
-					glColor3f(0.8f, 0.8f, 0.6f);
-					glBegin(GL_LINE_LOOP);
-					glVertex2f(getCenterFreqLineRelPos(dv->m_channelMarker), 0);
-					glVertex2f(getCenterFreqLineRelPos(dv->m_channelMarker), 1);
-					glEnd();
-				}
-
 				glDisable(GL_BLEND);
 				glPopMatrix();
 			}
 		}
+
+		// Center frequency mark on highlighted channels based on DSB enveloppe
+		for(int i = 0; i < m_channelMarkerStates.size(); ++i) {
+			ChannelMarkerState* dv = m_channelMarkerStates[i];
+			if(dv->m_channelMarker->getVisible()) {
+				if (dv->m_channelMarker->getHighlighted()) {
+					glColor3f(0.8f, 0.8f, 0.6f);
+					glPushMatrix();
+					glTranslatef(dv->m_glRectDsb.x(), dv->m_glRectDsb.y(), 0);
+					glScalef(dv->m_glRectDsb.width(), dv->m_glRectDsb.height(), 1);
+					glBegin(GL_LINE_LOOP);
+					glVertex2f(0.5, 0);
+					glVertex2f(0.5, 1);
+					glEnd();
+					glPopMatrix();
+				}
+			}
+		}
+
 		glPopMatrix();
 	}
 
@@ -1026,23 +1039,31 @@ void GLSpectrum::applyChanges()
 	for(int i = 0; i < m_channelMarkerStates.size(); ++i) {
 		ChannelMarkerState* dv = m_channelMarkerStates[i];
 
-		qreal xc, pw, nw;
+		qreal xc, pw, nw, dsbw;
 		ChannelMarker::sidebands_t sidebands = dv->m_channelMarker->getSidebands();
 		xc = m_centerFrequency + dv->m_channelMarker->getCenterFrequency(); // marker center frequency
+		dsbw = dv->m_channelMarker->getBandwidth();
 
 		if (sidebands == ChannelMarker::usb) {
-			nw = 0;                                       // negative bandwidth
+			nw = dv->m_channelMarker->getLowCutoff();     // negative bandwidth
 			pw = dv->m_channelMarker->getBandwidth() / 2; // positive bandwidth
 		} else if (sidebands == ChannelMarker::lsb) {
-			pw = 0;
+			pw = dv->m_channelMarker->getLowCutoff();
 			nw = dv->m_channelMarker->getBandwidth() / 2;
 		} else {
-			pw = dv->m_channelMarker->getBandwidth() / 2;
+			pw = dsbw / 2;
 			nw = -pw;
 		}
 
-		//std::cerr << xc << "; " << nw << "; " << pw << std::endl;
 
+		// draw the DSB rectangle
+		dv->m_glRectDsb.setRect(
+			m_frequencyScale.getPosFromValue(xc - (dsbw/2)) / (float)(width() - leftMargin - rightMargin),
+			0,
+			dsbw / (float)m_sampleRate,
+			1);
+
+		// draw the effective BW rectangle
 		dv->m_glRect.setRect(
 			m_frequencyScale.getPosFromValue(xc + nw) / (float)(width() - leftMargin - rightMargin),
 			0,
@@ -1366,16 +1387,3 @@ void GLSpectrum::channelMarkerDestroyed(QObject* object)
 {
 	removeChannelMarker((ChannelMarker*)object);
 }
-
-float GLSpectrum::getCenterFreqLineRelPos(ChannelMarker *channelMarker)
-{
-	ChannelMarker::sidebands_t sidebands = channelMarker->getSidebands();
-
-	if (sidebands == ChannelMarker::usb) {
-		return 0.0;
-	} else if (sidebands == ChannelMarker::lsb) {
-		return 1.0;
-	} else {
-		return 0.5;
-	}
-}