diff --git a/plugins/channelrx/sigmffilesink/CMakeLists.txt b/plugins/channelrx/sigmffilesink/CMakeLists.txt
index 447d4ba65..32fd0fe1d 100644
--- a/plugins/channelrx/sigmffilesink/CMakeLists.txt
+++ b/plugins/channelrx/sigmffilesink/CMakeLists.txt
@@ -5,6 +5,7 @@ set(sigmffilesink_SOURCES
     sigmffilesinkbaseband.cpp
     sigmffilesinksink.cpp
     sigmffilesinksettings.cpp
+    sigmffilesinkmessages.cpp
     sigmffilesinkwebapiadapter.cpp
     sigmffilesinkplugin.cpp
 )
@@ -14,6 +15,7 @@ set(sigmffilesink_HEADERS
     sigmffilesinkbaseband.h
     sigmffilesinksink.h
     sigmffilesinksettings.h
+    sigmffilesinkmessages.h
     sigmffilesinkwebapiadapter.h
 	sigmffilesinkplugin.h
 )
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesink.cpp b/plugins/channelrx/sigmffilesink/sigmffilesink.cpp
index 45ed13e66..4e2c8a1fa 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesink.cpp
+++ b/plugins/channelrx/sigmffilesink/sigmffilesink.cpp
@@ -47,11 +47,13 @@ SigMFFileSink::SigMFFileSink(DeviceAPI *deviceAPI) :
         m_deviceAPI(deviceAPI),
         m_centerFrequency(0),
         m_frequencyOffset(0),
+        m_spectrumVis(SDR_RX_SCALEF),
         m_basebandSampleRate(48000)
 {
     setObjectName(m_channelId);
 
     m_basebandSink = new SigMFFileSinkBaseband();
+    m_basebandSink->setSpectrumSink(&m_spectrumVis);
     m_basebandSink->moveToThread(&m_thread);
 
     applySettings(m_settings, true);
@@ -92,6 +94,7 @@ void SigMFFileSink::start()
 {
 	qDebug("SigMFFileSink::start");
     m_basebandSink->reset();
+    m_basebandSink->setMessageQueueToGUI(getMessageQueueToGUI());
     m_basebandSink->startWork();
     m_thread.start();
 
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesink.h b/plugins/channelrx/sigmffilesink/sigmffilesink.h
index c61d7edf5..3a0038af1 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesink.h
+++ b/plugins/channelrx/sigmffilesink/sigmffilesink.h
@@ -24,6 +24,7 @@
 #include <QNetworkRequest>
 
 #include "dsp/basebandsamplesink.h"
+#include "dsp/spectrumvis.h"
 #include "channel/channelapi.h"
 
 #include "sigmffilesinksettings.h"
@@ -108,6 +109,7 @@ public:
 
     void getLocalDevices(std::vector<uint32_t>& indexes);
     uint32_t getNumberOfDeviceStreams() const;
+    SpectrumVis *getSpectrumVis() { return &m_spectrumVis; }
     void record(bool record);
     uint64_t getMsCount() const;
     uint64_t getByteCount() const;
@@ -121,6 +123,7 @@ private:
     QThread m_thread;
     SigMFFileSinkBaseband *m_basebandSink;
     SigMFFileSinkSettings m_settings;
+    SpectrumVis m_spectrumVis;
 
     uint64_t m_centerFrequency;
     int64_t m_frequencyOffset;
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkbaseband.h b/plugins/channelrx/sigmffilesink/sigmffilesinkbaseband.h
index 25db34410..b4759cf19 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinkbaseband.h
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkbaseband.h
@@ -29,6 +29,7 @@
 #include "sigmffilesinksettings.h"
 
 class DownChannelizer;
+class SpectrumVis;
 
 class SigMFFileSinkBaseband : public QObject
 {
@@ -88,9 +89,11 @@ public:
     int getChannelSampleRate() const;
     void setBasebandSampleRate(int sampleRate);
     bool isRunning() const { return m_running; }
+    void setSpectrumSink(SpectrumVis* spectrumSink) { m_sink.setSpectrumSink(spectrumSink); }
     uint64_t getMsCount() const { return m_sink.getMsCount(); }
     uint64_t getByteCount() const { return m_sink.getByteCount(); }
     unsigned int getNbTracks() const { return m_sink.getNbTracks(); }
+    void setMessageQueueToGUI(MessageQueue *messageQueue) { m_sink.setMessageQueueToGUI(messageQueue); }
 
 private:
     SampleSinkFifo m_sampleFifo;
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.cpp b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.cpp
index 033b6b3f5..e6c23033a 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.cpp
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.cpp
@@ -27,8 +27,9 @@
 #include "dsp/dspcommands.h"
 #include "mainwindow.h"
 
-#include "sigmffilesinkgui.h"
+#include "sigmffilesinkmessages.h"
 #include "sigmffilesink.h"
+#include "sigmffilesinkgui.h"
 #include "ui_sigmffilesinkgui.h"
 
 SigMFFileSinkGUI* SigMFFileSinkGUI::create(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, BasebandSampleSink *channelRx)
@@ -117,6 +118,12 @@ bool SigMFFileSinkGUI::handleMessage(const Message& message)
         blockApplySettings(false);
         return true;
     }
+    else if (SigMFFileSinkMessages::MsgConfigureSpectrum::match(message))
+    {
+        const SigMFFileSinkMessages::MsgConfigureSpectrum& cfg = (SigMFFileSinkMessages::MsgConfigureSpectrum&) message;
+        ui->glSpectrum->setSampleRate(cfg.getSampleRate());
+        ui->glSpectrum->setCenterFrequency(cfg.getCenterFrequency());
+    }
     else
     {
         return false;
@@ -140,12 +147,15 @@ SigMFFileSinkGUI::SigMFFileSinkGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISe
     connect(this, SIGNAL(customContextMenuRequested(const QPoint &)), this, SLOT(onMenuDialogCalled(const QPoint &)));
 
     m_sigMFFileSink = (SigMFFileSink*) channelrx;
+    m_spectrumVis = m_sigMFFileSink->getSpectrumVis();
+	m_spectrumVis->setGLSpectrum(ui->glSpectrum);
     m_sigMFFileSink->setMessageQueueToGUI(getInputMessageQueue());
 
 	ui->deltaFrequencyLabel->setText(QString("%1f").arg(QChar(0x94, 0x03)));
     ui->deltaFrequency->setColorMapper(ColorMapper(ColorMapper::GrayGold));
     ui->deltaFrequency->setValueRange(false, 8, -99999999, 99999999);
     ui->position->setEnabled(m_fixedPosition);
+    ui->glSpectrumGUI->setBuddies(m_spectrumVis, ui->glSpectrum);
 
     m_channelMarker.blockSignals(true);
     m_channelMarker.setColor(m_settings.m_rgbColor);
@@ -155,7 +165,7 @@ SigMFFileSinkGUI::SigMFFileSinkGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISe
     m_channelMarker.blockSignals(false);
     m_channelMarker.setVisible(true); // activate signal on the last setting only
 
-    m_settings.setChannelMarker(&m_channelMarker);
+    m_settings.setSpectrumGUI(ui->glSpectrumGUI);
 
     m_deviceUISet->registerRxChannelInstance(SigMFFileSink::m_channelIdURI, this);
     m_deviceUISet->addChannelMarker(&m_channelMarker);
@@ -346,14 +356,11 @@ void SigMFFileSinkGUI::on_decimationFactor_currentIndexChanged(int index)
     applyDecimation();
     displayRate();
     displayPos();
+    applySettings();
 
-    if (m_fixedPosition)
-    {
+    if (m_fixedPosition) {
         setFrequencyFromPos();
-        applySettings();
-    }
-    else
-    {
+    } else {
         setPosFromFrequency();
     }
 }
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.h b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.h
index 670554b09..ef3c1b33f 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.h
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.h
@@ -33,6 +33,7 @@ class PluginAPI;
 class DeviceUISet;
 class SigMFFileSink;
 class BasebandSampleSink;
+class SpectrumVis;
 
 namespace Ui {
     class SigMFFileSinkGUI;
@@ -72,6 +73,7 @@ private:
     bool m_doApplySettings;
 
     SigMFFileSink* m_sigMFFileSink;
+    SpectrumVis* m_spectrumVis;
     MessageQueue m_inputMessageQueue;
 
     uint32_t m_tickCount;
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.ui b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.ui
index e14ec374e..84e0642e8 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinkgui.ui
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkgui.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>522</width>
-    <height>102</height>
+    <height>458</height>
    </rect>
   </property>
   <property name="minimumSize">
@@ -46,7 +46,7 @@
    <property name="windowTitle">
     <string>Settings</string>
    </property>
-   <layout class="QVBoxLayout" name="verticalLayout" stretch="0,0,0,0">
+   <layout class="QVBoxLayout" name="verticalLayout" stretch="0,0,0">
     <property name="leftMargin">
      <number>2</number>
     </property>
@@ -383,18 +383,39 @@
       </item>
      </layout>
     </item>
+   </layout>
+  </widget>
+  <widget class="QWidget" name="verticalLayoutWidget">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>100</y>
+     <width>521</width>
+     <height>351</height>
+    </rect>
+   </property>
+   <layout class="QVBoxLayout" name="SpectrumLayout">
+    <property name="spacing">
+     <number>10</number>
+    </property>
     <item>
-     <spacer name="verticalSpacer">
-      <property name="orientation">
-       <enum>Qt::Vertical</enum>
-      </property>
-      <property name="sizeHint" stdset="0">
+     <widget class="GLSpectrum" name="glSpectrum" native="true">
+      <property name="minimumSize">
        <size>
-        <width>20</width>
-        <height>40</height>
+        <width>0</width>
+        <height>300</height>
        </size>
       </property>
-     </spacer>
+      <property name="font">
+       <font>
+        <family>Liberation Mono</family>
+        <pointsize>8</pointsize>
+       </font>
+      </property>
+     </widget>
+    </item>
+    <item>
+     <widget class="GLSpectrumGUI" name="glSpectrumGUI" native="true"/>
     </item>
    </layout>
   </widget>
@@ -417,6 +438,18 @@
    <header>gui/valuedialz.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>
   <include location="../../../sdrgui/resources/res.qrc"/>
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.cpp b/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.cpp
new file mode 100644
index 000000000..9c48fed21
--- /dev/null
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.cpp
@@ -0,0 +1,20 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB.                                  //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "sigmffilesinkmessages.h"
+
+MESSAGE_CLASS_DEFINITION(SigMFFileSinkMessages::MsgConfigureSpectrum, Message)
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.h b/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.h
new file mode 100644
index 000000000..1198c9b75
--- /dev/null
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinkmessages.h
@@ -0,0 +1,51 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB.                                  //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_SIGMFFILESINKMESSAGES_H_
+#define INCLUDE_SIGMFFILESINKMESSAGES_H_
+
+#include <QObject>
+
+#include "util/message.h"
+
+class SigMFFileSinkMessages : public QObject {
+    Q_OBJECT
+public:
+    class MsgConfigureSpectrum : public Message {
+        MESSAGE_CLASS_DECLARATION
+
+    public:
+        int64_t getCenterFrequency() const { return m_centerFrequency; }
+        int getSampleRate() const { return m_sampleRate; }
+
+        static MsgConfigureSpectrum* create(int64_t centerFrequency, int sampleRate) {
+            return new MsgConfigureSpectrum(centerFrequency, sampleRate);
+        }
+
+    private:
+        int64_t m_centerFrequency;
+        int m_sampleRate;
+
+        MsgConfigureSpectrum(int64_t centerFrequency, int sampleRate) :
+            Message(),
+            m_centerFrequency(centerFrequency),
+            m_sampleRate(sampleRate)
+        { }
+    };
+};
+
+#endif // INCLUDE_SIGMFFILESINKMESSAGES_H_
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinksettings.cpp b/plugins/channelrx/sigmffilesink/sigmffilesinksettings.cpp
index 38b978f7d..8d0a04dbe 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinksettings.cpp
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinksettings.cpp
@@ -35,7 +35,7 @@ void SigMFFileSinkSettings::resetToDefaults()
     m_rgbColor = QColor(140, 4, 4).rgb();
     m_title = "SigMF File Sink";
     m_log2Decim = 0;
-    m_channelMarker = nullptr;
+    m_spectrumGUI = nullptr;
     m_streamIndex = 0;
     m_useReverseAPI = false;
     m_reverseAPIAddress = "127.0.0.1";
@@ -60,6 +60,10 @@ QByteArray SigMFFileSinkSettings::serialize() const
     s.writeU32(11, m_reverseAPIChannelIndex);
     s.writeU32(12, m_log2Decim);
 
+    if (m_spectrumGUI) {
+        s.writeBlob(13, m_spectrumGUI->serialize());
+    }
+
     return s.final();
 }
 
@@ -77,6 +81,7 @@ bool SigMFFileSinkSettings::deserialize(const QByteArray& data)
     {
         uint32_t tmp;
         QString strtmp;
+        QByteArray bytetmp;
 
         d.readS32(1, &m_inputFrequencyOffset, 0);
         d.readBool(2, &m_ncoMode, false);
@@ -101,6 +106,12 @@ bool SigMFFileSinkSettings::deserialize(const QByteArray& data)
         d.readU32(12, &tmp, 0);
         m_log2Decim = tmp > 6 ? 6 : tmp;
 
+        if (m_spectrumGUI)
+        {
+            d.readBlob(13, &bytetmp);
+            m_spectrumGUI->deserialize(bytetmp);
+        }
+
         return true;
     }
     else
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinksettings.h b/plugins/channelrx/sigmffilesink/sigmffilesinksettings.h
index 5b72a3fc6..0aaffb409 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinksettings.h
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinksettings.h
@@ -38,11 +38,11 @@ struct SigMFFileSinkSettings
     uint16_t m_reverseAPIDeviceIndex;
     uint16_t m_reverseAPIChannelIndex;
 
-    Serializable *m_channelMarker;
+    Serializable *m_spectrumGUI;
 
     SigMFFileSinkSettings();
     void resetToDefaults();
-    void setChannelMarker(Serializable *channelMarker) { m_channelMarker = channelMarker; }
+    void setSpectrumGUI(Serializable *spectrumGUI) { m_spectrumGUI = spectrumGUI; }
     QByteArray serialize() const;
     bool deserialize(const QByteArray& data);
 
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinksink.cpp b/plugins/channelrx/sigmffilesink/sigmffilesinksink.cpp
index ab90c715c..21a1b866f 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinksink.cpp
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinksink.cpp
@@ -19,10 +19,14 @@
 
 #include "dsp/dspcommands.h"
 #include "dsp/sigmffilerecord.h"
+#include "dsp/spectrumvis.h"
 
+#include "sigmffilesinkmessages.h"
 #include "sigmffilesinksink.h"
 
 SigMFFileSinkSink::SigMFFileSinkSink() :
+    m_spectrumSink(nullptr),
+    m_msgQueueToGUI(nullptr),
     m_recordEnabled(false),
     m_record(false),
     m_msCount(0),
@@ -81,6 +85,10 @@ void SigMFFileSinkSink::feed(const SampleVector::const_iterator& begin, const Sa
         }
     }
 
+    if (m_spectrumSink) {
+		m_spectrumSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), false);
+	}
+
     m_sampleBuffer.clear();
 }
 
@@ -107,7 +115,7 @@ void SigMFFileSinkSink::applyChannelSettings(
     if ((m_channelSampleRate != channelSampleRate)
      || (m_sinkSampleRate != sinkSampleRate) || force)
     {
-        m_interpolator.create(16, channelSampleRate, channelSampleRate / 2.2f);
+        m_interpolator.create(16, channelSampleRate, channelSampleRate / 2.0f);
         m_interpolatorDistanceRemain = 0;
         m_interpolatorDistance = (Real) channelSampleRate / (Real) sinkSampleRate;
     }
@@ -116,8 +124,17 @@ void SigMFFileSinkSink::applyChannelSettings(
      || (m_channelFrequencyOffset != channelFrequencyOffset)
      || (m_sinkSampleRate != sinkSampleRate) || force)
     {
-        DSPSignalNotification *notif = new DSPSignalNotification(sinkSampleRate, centerFrequency + m_settings.m_inputFrequencyOffset);
+        DSPSignalNotification *notif = new DSPSignalNotification(sinkSampleRate, centerFrequency);
+        DSPSignalNotification *notifToSpectrum = new DSPSignalNotification(*notif);
         m_fileSink.getInputMessageQueue()->push(notif);
+        m_spectrumSink->getInputMessageQueue()->push(notifToSpectrum);
+
+        if (m_msgQueueToGUI)
+        {
+            SigMFFileSinkMessages::MsgConfigureSpectrum *msg = SigMFFileSinkMessages::MsgConfigureSpectrum::create(
+                centerFrequency, sinkSampleRate);
+            m_msgQueueToGUI->push(msg);
+        }
     }
 
     m_channelSampleRate = channelSampleRate;
@@ -129,8 +146,6 @@ void SigMFFileSinkSink::applyChannelSettings(
 void SigMFFileSinkSink::applySettings(const SigMFFileSinkSettings& settings, bool force)
 {
     qDebug() << "SigMFFileSinkSink::applySettings:"
-        << "m_log2Decim:" << settings.m_log2Decim
-        << "m_inputFrequencyOffset:" << settings.m_inputFrequencyOffset
         << "m_fileRecordName: " << settings.m_fileRecordName
         << "force: " << force;
 
@@ -152,11 +167,5 @@ void SigMFFileSinkSink::applySettings(const SigMFFileSinkSettings& settings, boo
         }
     }
 
-    if ((settings.m_inputFrequencyOffset != m_settings.m_inputFrequencyOffset) || force)
-    {
-        DSPSignalNotification *notif = new DSPSignalNotification(m_sinkSampleRate, m_centerFrequency + m_settings.m_inputFrequencyOffset);
-        m_fileSink.getInputMessageQueue()->push(notif);
-    }
-
     m_settings = settings;
 }
diff --git a/plugins/channelrx/sigmffilesink/sigmffilesinksink.h b/plugins/channelrx/sigmffilesink/sigmffilesinksink.h
index 8adb457c1..57fe7d11a 100644
--- a/plugins/channelrx/sigmffilesink/sigmffilesinksink.h
+++ b/plugins/channelrx/sigmffilesink/sigmffilesinksink.h
@@ -26,6 +26,7 @@
 #include "sigmffilesinksettings.h"
 
 class FileRecordInterface;
+class SpectrumVis;
 
 class SigMFFileSinkSink : public ChannelSampleSink {
 public:
@@ -35,6 +36,7 @@ public:
 	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end);
 
     SigMFFileRecord *getFileSink() { return &m_fileSink; }
+    void setSpectrumSink(SpectrumVis* spectrumSink) { m_spectrumSink = spectrumSink; }
     void startRecording();
     void stopRecording();
     void setDeviceHwId(const QString& hwId) { m_deviceHwId = hwId; }
@@ -49,6 +51,7 @@ public:
     uint64_t getMsCount() const { return m_msCount; }
     uint64_t getByteCount() const { return m_byteCount; }
     unsigned int getNbTracks() const { return m_fileSink.getNbCaptures(); }
+    void setMessageQueueToGUI(MessageQueue *messageQueue) { m_msgQueueToGUI = messageQueue; }
 
 private:
     int m_channelSampleRate;
@@ -62,6 +65,8 @@ private:
     SampleVector m_sampleBuffer;
     SigMFFileSinkSettings m_settings;
     SigMFFileRecord m_fileSink;
+    SpectrumVis* m_spectrumSink;
+    MessageQueue *m_msgQueueToGUI;
     bool m_recordEnabled;
     bool m_record;
     QString m_deviceHwId;