diff --git a/Readme.md b/Readme.md
index 90d3fa11c..f7600dfa6 100644
--- a/Readme.md
+++ b/Readme.md
@@ -39,6 +39,7 @@ Since version 2 SDRangel can integrate more than one hardware device running con
 Since version 3 transmission or signal generation is supported for BladeRF, HackRF (since version 3.1), LimeSDR (since version 3.4) and PlutoSDR (since version 3.7.8) using a sample sink plugin. These plugins are:
 
   - [BladeRF1 output plugin](https://github.com/f4exb/sdrangel/tree/dev/plugins/samplesink/bladerf1output)
+  - [BladeRF2 output plugin](https://github.com/f4exb/sdrangel/tree/dev/plugins/samplesink/bladerf2output)
   - [HackRF output plugin](https://github.com/f4exb/sdrangel/tree/dev/plugins/samplesink/hackrfoutput)
   - [LimeSDR output plugin](https://github.com/f4exb/sdrangel/tree/dev/plugins/samplesink/limesdroutput)
   - [PlutoSDR output plugin](https://github.com/f4exb/sdrangel/tree/dev/plugins/samplesink/plutosdroutput)
@@ -114,7 +115,7 @@ The plugins used to support BladeRF classic are specific to this version of the
 
 <h2>BladeRF micro (v.2)</h2>
 
-From version 4.2.0. Output (Tx) for Linux only.
+From version 4.2.0.
 
 [BladeRF 2 micro](https://www.nuand.com/bladerf-2-0-micro/) is also supported using libbladeRF library that should be installed and configured in the same way as for BladeRF1.
 
diff --git a/debian/changelog b/debian/changelog
index a977768c6..10534c313 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,7 +1,14 @@
+sdrangel (4.2.2-1) unstable; urgency=medium
+
+  * Spectrum: option to get max over a number of FFTs. Implements issue #207
+
+ -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Sun, 14 Oct 2018 21:14:18 +0200
+
 sdrangel (4.2.1-1) unstable; urgency=medium
 
   * FileRecord improvement with robust header and some fixes. Fixes issue #206
   * BladeRF2 MO Tx fix so that the two channels are used effectively. Fixes issue #225
+  * NFM demod: set squelch step to 1 dB
 
  -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Wed, 10 Oct 2018 21:14:18 +0200
 
diff --git a/plugins/samplesink/bladerf2output/readme.md b/plugins/samplesink/bladerf2output/readme.md
index 070ffc554..8719e7163 100644
--- a/plugins/samplesink/bladerf2output/readme.md
+++ b/plugins/samplesink/bladerf2output/readme.md
@@ -2,7 +2,7 @@
 
 <h2>Introduction</h2>
 
-This output sample sink plugin sends its samples to a [BladeRF2 device](https://www.nuand.com/bladerf-2). This is available since v4.2.0 in Linux distributions only.
+This output sample sink plugin sends its samples to a [BladeRF2 device](https://www.nuand.com/bladerf-2). This is available since v4.2.0.
 
 <h2>Build</h2>
 
diff --git a/sdrbase/util/fixedaverage2d.h b/sdrbase/util/fixedaverage2d.h
index 192dcfe6a..c9f7b0ffa 100644
--- a/sdrbase/util/fixedaverage2d.h
+++ b/sdrbase/util/fixedaverage2d.h
@@ -24,7 +24,7 @@ template<typename T>
 class FixedAverage2D
 {
 public:
-    FixedAverage2D() : m_sum(0), m_sumSize(0), m_width(0), m_size(0), m_avgIndex(0) {}
+    FixedAverage2D() : m_sum(0), m_maxSize(0), m_width(0), m_size(0), m_maxIndex(0) {}
 
     ~FixedAverage2D()
     {
@@ -35,20 +35,20 @@ public:
 
     void resize(unsigned int width, unsigned int size)
     {
-        if (width > m_sumSize)
+        if (width > m_maxSize)
         {
-            m_sumSize = width;
+            m_maxSize = width;
             if (m_sum) {
                 delete[] m_sum;
             }
-            m_sum = new T[m_sumSize];
+            m_sum = new T[m_maxSize];
         }
 
         m_width = width;
         m_size = size;
 
         std::fill(m_sum, m_sum+m_width, 0);
-        m_avgIndex = 0;
+        m_maxIndex = 0;
     }
 
     bool storeAndGetAvg(T& avg, T v, unsigned int index)
@@ -61,7 +61,7 @@ public:
 
         m_sum[index] += v;
 
-        if (m_avgIndex == m_size - 1)
+        if (m_maxIndex == m_size - 1)
         {
             avg = m_sum[index]/m_size;
             return true;
@@ -82,7 +82,7 @@ public:
 
         m_sum[index] += v;
 
-        if (m_avgIndex < m_size - 1)
+        if (m_maxIndex < m_size - 1)
         {
             sum = m_sum[index];
             return true;
@@ -99,25 +99,25 @@ public:
             return true;
         }
 
-        if (m_avgIndex == m_size - 1)
+        if (m_maxIndex == m_size - 1)
         {
-            m_avgIndex = 0;
+            m_maxIndex = 0;
             std::fill(m_sum, m_sum+m_width, 0);
             return true;
         }
         else
         {
-            m_avgIndex++;
+            m_maxIndex++;
             return false;
         }
     }
 
 private:
     T *m_sum;
-    unsigned int m_sumSize;
+    unsigned int m_maxSize;
     unsigned int m_width;
     unsigned int m_size;
-    unsigned int m_avgIndex;
+    unsigned int m_maxIndex;
 };
 
 
diff --git a/sdrbase/util/max2d.h b/sdrbase/util/max2d.h
new file mode 100644
index 000000000..58be966c9
--- /dev/null
+++ b/sdrbase/util/max2d.h
@@ -0,0 +1,107 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 F4EXB                                                      //
+// written by Edouard Griffiths                                                  //
+//                                                                               //
+// 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                  //
+//                                                                               //
+// 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 SDRBASE_UTIL_MAX2D_H_
+#define SDRBASE_UTIL_MAX2D_H_
+
+#include <algorithm>
+
+template<typename T>
+class Max2D
+{
+public:
+    Max2D() : m_max(0), m_maxSize(0), m_width(0), m_size(0), m_maxIndex(0) {}
+
+    ~Max2D()
+    {
+        if (m_max) {
+            delete[] m_max;
+        }
+    }
+
+    void resize(unsigned int width, unsigned int size)
+    {
+        if (width > m_maxSize)
+        {
+            m_maxSize = width;
+            if (m_max) {
+                delete[] m_max;
+            }
+            m_max = new T[m_maxSize];
+        }
+
+        m_width = width;
+        m_size = size;
+
+        std::fill(m_max, m_max+m_width, 0);
+        m_maxIndex = 0;
+    }
+
+    bool storeAndGetMax(T& max, T v, unsigned int index)
+    {
+        if (m_size <= 1)
+        {
+            max = v;
+            return true;
+        }
+
+        if (m_maxIndex == 0)
+        {
+            m_max[index] = v;
+            return false;
+        }
+        else if (m_maxIndex == m_size - 1)
+        {
+            m_max[index] = std::max(m_max[index], v);
+            max = m_max[index];
+            return true;
+        }
+        else
+        {
+            m_max[index] = std::max(m_max[index], v);
+            return false;
+        }
+    }
+
+    bool nextMax()
+    {
+        if (m_size <= 1) {
+            return true;
+        }
+
+        if (m_maxIndex == m_size - 1)
+        {
+            m_maxIndex = 0;
+            std::fill(m_max, m_max+m_width, 0);
+            return true;
+        }
+        else
+        {
+            m_maxIndex++;
+            return false;
+        }
+    }
+
+private:
+    T *m_max;
+    unsigned int m_maxSize;
+    unsigned int m_width;
+    unsigned int m_size;
+    unsigned int m_maxIndex;
+};
+
+#endif /* SDRBASE_UTIL_MAX2D_H_ */
diff --git a/sdrgui/dsp/spectrumvis.cpp b/sdrgui/dsp/spectrumvis.cpp
index 7bc7f5426..0389cdc91 100644
--- a/sdrgui/dsp/spectrumvis.cpp
+++ b/sdrgui/dsp/spectrumvis.cpp
@@ -26,7 +26,7 @@ SpectrumVis::SpectrumVis(Real scalef, GLSpectrum* glSpectrum) :
 	m_scalef(scalef),
 	m_glSpectrum(glSpectrum),
 	m_averageNb(0),
-	m_averagingMode(AvgModeNone),
+	m_avgMode(AvgModeNone),
 	m_linear(false),
 	m_ofs(0),
     m_powFFTDiv(1.0),
@@ -114,7 +114,7 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
 			Real v;
 			std::size_t halfSize = m_fftSize / 2;
 
-			if (m_averagingMode == AvgModeNone)
+			if (m_avgMode == AvgModeNone)
 			{
                 if ( positiveOnly )
                 {
@@ -146,7 +146,7 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
                 // send new data to visualisation
                 m_glSpectrum->newSpectrum(m_powerSpectrum, m_fftSize);
 			}
-			else if (m_averagingMode == AvgModeMoving)
+			else if (m_avgMode == AvgModeMovingAvg)
 			{
 	            if ( positiveOnly )
 	            {
@@ -182,7 +182,7 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
 	            m_glSpectrum->newSpectrum(m_powerSpectrum, m_fftSize);
 	            m_movingAverage.nextAverage();
 			}
-			else if (m_averagingMode == AvgModeFixed)
+			else if (m_avgMode == AvgModeFixedAvg)
 			{
 			    double avg;
 
@@ -195,7 +195,7 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
 
                         if (m_fixedAverage.storeAndGetAvg(avg, v, i))
                         {
-                            avg = m_linear ? v/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
+                            avg = m_linear ? avg/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
                             m_powerSpectrum[i * 2] = avg;
                             m_powerSpectrum[i * 2 + 1] = avg;
                         }
@@ -210,7 +210,7 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
 
                         if (m_fixedAverage.storeAndGetAvg(avg, v, i+halfSize))
                         { // result available
-                            avg = m_linear ? v/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
+                            avg = m_linear ? avg/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
                             m_powerSpectrum[i] = avg;
                         }
 
@@ -219,16 +219,61 @@ void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleV
 
                         if (m_fixedAverage.storeAndGetAvg(avg, v, i))
                         { // result available
-                            avg = m_linear ? v/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
+                            avg = m_linear ? avg/m_powFFTDiv : m_mult * log2f(avg) + m_ofs;
                             m_powerSpectrum[i + halfSize] = avg;
                         }
                     }
                 }
 
-                if (m_fixedAverage.nextAverage())
-                { // result available
-                    // send new data to visualisation
-                    m_glSpectrum->newSpectrum(m_powerSpectrum, m_fftSize);
+                if (m_fixedAverage.nextAverage()) { // result available
+                    m_glSpectrum->newSpectrum(m_powerSpectrum, m_fftSize); // send new data to visualisation
+                }
+			}
+			else if (m_avgMode == AvgModeMax)
+			{
+			    double max;
+
+                if ( positiveOnly )
+                {
+                    for (std::size_t i = 0; i < halfSize; i++)
+                    {
+                        c = fftOut[i];
+                        v = c.real() * c.real() + c.imag() * c.imag();
+
+                        if (m_max.storeAndGetMax(max, v, i))
+                        {
+                            max = m_linear ? max/m_powFFTDiv : m_mult * log2f(max) + m_ofs;
+                            m_powerSpectrum[i * 2] = max;
+                            m_powerSpectrum[i * 2 + 1] = max;
+                        }
+                    }
+                }
+                else
+                {
+                    for (std::size_t i = 0; i < halfSize; i++)
+                    {
+                        c = fftOut[i + halfSize];
+                        v = c.real() * c.real() + c.imag() * c.imag();
+
+                        if (m_max.storeAndGetMax(max, v, i+halfSize))
+                        { // result available
+                            max = m_linear ? max/m_powFFTDiv : m_mult * log2f(max) + m_ofs;
+                            m_powerSpectrum[i] = max;
+                        }
+
+                        c = fftOut[i];
+                        v = c.real() * c.real() + c.imag() * c.imag();
+
+                        if (m_max.storeAndGetMax(max, v, i))
+                        { // result available
+                            max = m_linear ? max/m_powFFTDiv : m_mult * log2f(max) + m_ofs;
+                            m_powerSpectrum[i + halfSize] = max;
+                        }
+                    }
+                }
+
+                if (m_max.nextMax()) { // result available
+                    m_glSpectrum->newSpectrum(m_powerSpectrum, m_fftSize); // send new data to visualisation
                 }
 			}
 
@@ -269,7 +314,7 @@ bool SpectrumVis::handleMessage(const Message& message)
 		handleConfigure(conf.getFFTSize(),
 		        conf.getOverlapPercent(),
 		        conf.getAverageNb(),
-		        conf.getAveragingMode(),
+		        conf.getAvgMode(),
 		        conf.getWindow(),
 		        conf.getLinear());
 		return true;
@@ -283,10 +328,12 @@ bool SpectrumVis::handleMessage(const Message& message)
 void SpectrumVis::handleConfigure(int fftSize,
         int overlapPercent,
         unsigned int averageNb,
-        AveragingMode averagingMode,
+        AvgMode averagingMode,
         FFTWindow::Function window,
         bool linear)
 {
+//    qDebug("SpectrumVis::handleConfigure, fftSize: %d overlapPercent: %d averageNb: %u averagingMode: %d window: %d linear: %s",
+//            fftSize, overlapPercent, averageNb, (int) averagingMode, (int) window, linear ? "true" : "false");
 	QMutexLocker mutexLocker(&m_mutex);
 
 	if (fftSize > MAX_FFT_SIZE)
@@ -319,8 +366,9 @@ void SpectrumVis::handleConfigure(int fftSize,
 	m_fftBufferFill = m_overlapSize;
 	m_movingAverage.resize(fftSize, averageNb);
 	m_fixedAverage.resize(fftSize, averageNb);
+	m_max.resize(fftSize, averageNb);
 	m_averageNb = averageNb;
-	m_averagingMode = averagingMode;
+	m_avgMode = averagingMode;
 	m_linear = linear;
 	m_ofs = 20.0f * log10f(1.0f / m_fftSize);
 	m_powFFTDiv = m_fftSize*m_fftSize;
diff --git a/sdrgui/dsp/spectrumvis.h b/sdrgui/dsp/spectrumvis.h
index a86a5c0fd..b01c6459d 100644
--- a/sdrgui/dsp/spectrumvis.h
+++ b/sdrgui/dsp/spectrumvis.h
@@ -9,6 +9,7 @@
 #include "util/message.h"
 #include "util/movingaverage2d.h"
 #include "util/fixedaverage2d.h"
+#include "util/max2d.h"
 
 class GLSpectrum;
 class MessageQueue;
@@ -16,11 +17,12 @@ class MessageQueue;
 class SDRGUI_API SpectrumVis : public BasebandSampleSink {
 
 public:
-    enum AveragingMode
+    enum AvgMode
     {
         AvgModeNone,
-        AvgModeMoving,
-        AvgModeFixed
+        AvgModeMovingAvg,
+        AvgModeFixedAvg,
+        AvgModeMax
     };
 
 	class MsgConfigureSpectrumVis : public Message {
@@ -31,7 +33,7 @@ public:
 		        int fftSize,
 		        int overlapPercent,
 		        unsigned int averageNb,
-		        int averagingMode,
+		        int preProcessMode,
 		        FFTWindow::Function window,
 		        bool linear) :
 			Message(),
@@ -41,13 +43,13 @@ public:
 			m_window(window),
 			m_linear(linear)
 		{
-		    m_averagingMode = averagingMode < 0 ? AvgModeNone : averagingMode > 2 ? AvgModeFixed : (SpectrumVis::AveragingMode) averagingMode;
+		    m_avgMode = preProcessMode < 0 ? AvgModeNone : preProcessMode > 3 ? AvgModeMax : (SpectrumVis::AvgMode) preProcessMode;
 		}
 
 		int getFFTSize() const { return m_fftSize; }
 		int getOverlapPercent() const { return m_overlapPercent; }
 		unsigned int getAverageNb() const { return m_averageNb; }
-		SpectrumVis::AveragingMode getAveragingMode() const { return m_averagingMode; }
+		SpectrumVis::AvgMode getAvgMode() const { return m_avgMode; }
 		FFTWindow::Function getWindow() const { return m_window; }
 		bool getLinear() const { return m_linear; }
 
@@ -55,7 +57,7 @@ public:
 		int m_fftSize;
 		int m_overlapPercent;
 		unsigned int m_averageNb;
-		SpectrumVis::AveragingMode m_averagingMode;
+		SpectrumVis::AvgMode m_avgMode;
 		FFTWindow::Function m_window;
 		bool m_linear;
 	};
@@ -95,8 +97,9 @@ private:
 	GLSpectrum* m_glSpectrum;
 	MovingAverage2D<double> m_movingAverage;
 	FixedAverage2D<double> m_fixedAverage;
+	Max2D<double> m_max;
 	unsigned int m_averageNb;
-	AveragingMode m_averagingMode;
+	AvgMode m_avgMode;
 	bool m_linear;
 
 	Real m_ofs;
@@ -108,7 +111,7 @@ private:
 	void handleConfigure(int fftSize,
 	        int overlapPercent,
 	        unsigned int averageNb,
-	        AveragingMode averagingMode,
+	        AvgMode averagingMode,
 	        FFTWindow::Function window,
 	        bool linear);
 };
diff --git a/sdrgui/gui/glspectrumgui.cpp b/sdrgui/gui/glspectrumgui.cpp
index 62a200437..d0ba90b1d 100644
--- a/sdrgui/gui/glspectrumgui.cpp
+++ b/sdrgui/gui/glspectrumgui.cpp
@@ -141,7 +141,7 @@ bool GLSpectrumGUI::deserialize(const QByteArray& data)
 		Real waterfallShare;
 		d.readReal(18, &waterfallShare, 0.66);
 		d.readS32(19, &tmp, 0);
-		m_averagingMode = tmp < 0 ? AvgModeNone : tmp > 2 ? AvgModeFixed : (AveragingMode) tmp;
+		m_averagingMode = tmp < 0 ? AvgModeNone : tmp > 3 ? AvgModeMax : (AveragingMode) tmp;
 		d.readS32(20, &tmp, 0);
 		m_averagingIndex = getAveragingIndex(tmp);
 	    m_averagingNb = getAveragingValue(m_averagingIndex);
@@ -244,7 +244,7 @@ void GLSpectrumGUI::on_fftSize_currentIndexChanged(int index)
 
 void GLSpectrumGUI::on_averagingMode_currentIndexChanged(int index)
 {
-    m_averagingMode = index < 0 ? AvgModeNone : index > 2 ? AvgModeFixed : (AveragingMode) index;
+    m_averagingMode = index < 0 ? AvgModeNone : index > 3 ? AvgModeMax : (AveragingMode) index;
 
     if(m_spectrumVis != 0) {
         m_spectrumVis->configure(m_messageQueueToVis,
@@ -258,7 +258,7 @@ void GLSpectrumGUI::on_averagingMode_currentIndexChanged(int index)
 
     if (m_glSpectrum != 0)
     {
-        if (m_averagingMode == AvgModeFixed) {
+        if ((m_averagingMode == AvgModeFixed) || (m_averagingMode == AvgModeMax)) {
             m_glSpectrum->setTimingRate(m_averagingNb == 0 ? 1 : m_averagingNb);
         } else {
             m_glSpectrum->setTimingRate(1);
@@ -283,8 +283,10 @@ void GLSpectrumGUI::on_averaging_currentIndexChanged(int index)
 
     if (m_glSpectrum != 0)
     {
-        if (m_averagingMode == AvgModeFixed) {
+        if ((m_averagingMode == AvgModeFixed) || (m_averagingMode == AvgModeMax)) {
             m_glSpectrum->setTimingRate(m_averagingNb == 0 ? 1 : m_averagingNb);
+        } else {
+            m_glSpectrum->setTimingRate(1);
         }
     }
 
diff --git a/sdrgui/gui/glspectrumgui.h b/sdrgui/gui/glspectrumgui.h
index 13d305231..9cf02a20d 100644
--- a/sdrgui/gui/glspectrumgui.h
+++ b/sdrgui/gui/glspectrumgui.h
@@ -22,7 +22,8 @@ public:
     {
         AvgModeNone,
         AvgModeMoving,
-        AvgModeFixed
+        AvgModeFixed,
+        AvgModeMax
     };
 
 	explicit GLSpectrumGUI(QWidget* parent = NULL);
diff --git a/sdrgui/gui/glspectrumgui.ui b/sdrgui/gui/glspectrumgui.ui
index 277c560ed..a874c7068 100644
--- a/sdrgui/gui/glspectrumgui.ui
+++ b/sdrgui/gui/glspectrumgui.ui
@@ -565,6 +565,11 @@
          <string>Fix</string>
         </property>
        </item>
+       <item>
+        <property name="text">
+         <string>Max</string>
+        </property>
+       </item>
       </widget>
      </item>
      <item>