diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.cpp b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.cpp
index ea6102c72..d06829c8d 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.cpp
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.cpp
@@ -224,14 +224,20 @@ void SDRdaemonSinkGui::updateSampleRateAndFrequency()
     ui->deviceRateText->setText(tr("%1k").arg((float)(m_sampleRate*(1<<m_settings.m_log2Interp)) / 1000));
 }
 
+void SDRdaemonSinkGui::updateTxDelayTooltip()
+{
+    double delay = ((127*127*m_settings.m_txDelay) / m_settings.m_sampleRate)/(128 + m_settings.m_nbFECBlocks);
+    ui->txDelayText->setToolTip(tr("%1 us").arg(QString::number(delay*1e6, 'f', 0)));
+}
+
 void SDRdaemonSinkGui::displaySettings()
 {
     ui->centerFrequency->setValue(m_settings.m_centerFrequency / 1000);
     ui->sampleRate->setValue(m_settings.m_sampleRate);
     ui->deviceRateText->setText(tr("%1k").arg((float)(m_sampleRate*(1<<m_settings.m_log2Interp)) / 1000));
     ui->interp->setCurrentIndex(m_settings.m_log2Interp);
-    ui->txDelay->setValue(m_settings.m_txDelay/10);
-    ui->txDelayText->setText(tr("%1").arg(m_settings.m_txDelay));
+    ui->txDelay->setValue(m_settings.m_txDelay*100);
+    ui->txDelayText->setText(tr("%1").arg(m_settings.m_txDelay*100));
     ui->nbFECBlocks->setValue(m_settings.m_nbFECBlocks);
 
     QString s0 = QString::number(128 + m_settings.m_nbFECBlocks, 'f', 0);
@@ -389,6 +395,7 @@ void SDRdaemonSinkGui::on_centerFrequency_changed(quint64 value)
 void SDRdaemonSinkGui::on_sampleRate_changed(quint64 value)
 {
     m_settings.m_sampleRate = value;
+    updateTxDelayTooltip();
     sendControl();
     sendSettings();
 }
@@ -406,8 +413,9 @@ void SDRdaemonSinkGui::on_interp_currentIndexChanged(int index)
 
 void SDRdaemonSinkGui::on_txDelay_valueChanged(int value)
 {
-    m_settings.m_txDelay = value * 10;
-    ui->txDelayText->setText(tr("%1").arg(10*value));
+    m_settings.m_txDelay = value / 100.0;
+    ui->txDelayText->setText(tr("%1").arg(value));
+    updateTxDelayTooltip();
     sendSettings();
 }
 
@@ -419,6 +427,7 @@ void SDRdaemonSinkGui::on_nbFECBlocks_valueChanged(int value)
     QString s = QString::number(nbOriginalBlocks + nbFECBlocks, 'f', 0);
     QString s1 = QString::number(nbFECBlocks, 'f', 0);
     ui->nominalNbBlocksText->setText(tr("%1/%2").arg(s).arg(s1));
+    updateTxDelayTooltip();
     sendSettings();
 }
 
diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.h b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.h
index 2f10bf23d..adc1137b9 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.h
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.h
@@ -85,6 +85,7 @@ private:
 	void sendSettings();
 	void updateWithStreamTime();
 	void updateSampleRateAndFrequency();
+	void updateTxDelayTooltip();
 	void displayEventCounts();
     void displayEventTimer();
 
diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.ui b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.ui
index fcab4e84d..6f8e1e5e7 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.ui
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkgui.ui
@@ -293,16 +293,19 @@
         </size>
        </property>
        <property name="toolTip">
-        <string>Delay in microseconds between consecutive UDP packets</string>
+        <string>Delay between consecutive UDP packets in percentage of nominal UDP packet process time</string>
        </property>
        <property name="minimum">
-        <number>1</number>
+        <number>10</number>
        </property>
        <property name="maximum">
-        <number>200</number>
+        <number>90</number>
        </property>
        <property name="pageStep">
-        <number>1</number>
+        <number>0</number>
+       </property>
+       <property name="value">
+        <number>50</number>
        </property>
       </widget>
      </item>
@@ -310,12 +313,18 @@
       <widget class="QLabel" name="txDelayText">
        <property name="minimumSize">
         <size>
-         <width>32</width>
+         <width>20</width>
          <height>0</height>
         </size>
        </property>
+       <property name="maximumSize">
+        <size>
+         <width>20</width>
+         <height>16777215</height>
+        </size>
+       </property>
        <property name="text">
-        <string>0000</string>
+        <string>90</string>
        </property>
        <property name="alignment">
         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkoutput.cpp b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkoutput.cpp
index 27497f51f..2457b16bd 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkoutput.cpp
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinkoutput.cpp
@@ -64,11 +64,13 @@ bool SDRdaemonSinkOutput::start()
 	m_sdrDaemonSinkThread->setRemoteAddress(m_settings.m_address, m_settings.m_dataPort);
 	m_sdrDaemonSinkThread->setCenterFrequency(m_settings.m_centerFrequency);
 	m_sdrDaemonSinkThread->setSamplerate(m_settings.m_sampleRate);
-	m_sdrDaemonSinkThread->setTxDelay(m_settings.m_txDelay);
 	m_sdrDaemonSinkThread->setNbBlocksFEC(m_settings.m_nbFECBlocks);
 	m_sdrDaemonSinkThread->connectTimer(m_masterTimer);
 	m_sdrDaemonSinkThread->startWork();
 
+    double delay = ((127*127*m_settings.m_txDelay) / m_settings.m_sampleRate)/(128 + m_settings.m_nbFECBlocks);
+    m_sdrDaemonSinkThread->setTxDelay((int) (delay*1e6));
+
 	mutexLocker.unlock();
 	//applySettings(m_generalSettings, m_settings, true);
 	qDebug("SDRdaemonSinkOutput::start: started");
@@ -171,6 +173,7 @@ void SDRdaemonSinkOutput::applySettings(const SDRdaemonSinkSettings& settings, b
 {
     QMutexLocker mutexLocker(&m_mutex);
     bool forwardChange = false;
+    bool changeTxDelay = false;
 
     if (force || (m_settings.m_address != settings.m_address) || (m_settings.m_dataPort != settings.m_dataPort))
     {
@@ -205,6 +208,7 @@ void SDRdaemonSinkOutput::applySettings(const SDRdaemonSinkSettings& settings, b
         }
 
         forwardChange = true;
+        changeTxDelay = true;
     }
 
     if (force || (m_settings.m_log2Interp != settings.m_log2Interp))
@@ -213,16 +217,6 @@ void SDRdaemonSinkOutput::applySettings(const SDRdaemonSinkSettings& settings, b
         forwardChange = true;
     }
 
-    if (force || (m_settings.m_txDelay != settings.m_txDelay))
-    {
-        m_settings.m_txDelay = settings.m_txDelay;
-
-        if (m_sdrDaemonSinkThread != 0)
-        {
-            m_sdrDaemonSinkThread->setTxDelay(m_settings.m_txDelay);
-        }
-    }
-
     if (force || (m_settings.m_nbFECBlocks != settings.m_nbFECBlocks))
     {
         m_settings.m_nbFECBlocks = settings.m_nbFECBlocks;
@@ -231,11 +225,34 @@ void SDRdaemonSinkOutput::applySettings(const SDRdaemonSinkSettings& settings, b
         {
             m_sdrDaemonSinkThread->setNbBlocksFEC(m_settings.m_nbFECBlocks);
         }
+
+        changeTxDelay = true;
+    }
+
+    if (force || (m_settings.m_txDelay != settings.m_txDelay))
+    {
+        m_settings.m_txDelay = settings.m_txDelay;
+        changeTxDelay = true;
+    }
+
+    if (changeTxDelay)
+    {
+        double delay = ((127*127*m_settings.m_txDelay) / m_settings.m_sampleRate)/(128 + m_settings.m_nbFECBlocks);
+        qDebug("SDRdaemonSinkOutput::applySettings: Tx delay: %f us", delay*1e6);
+
+        if (m_sdrDaemonSinkThread != 0)
+        {
+            // delay is calculated as a fraction of the nominal UDP block process time
+            // frame size: 127 * 127 samples
+            // divided by sample rate gives the frame process time
+            // divided by the number of actual blocks including FEC blocks gives the block (i.e. UDP block) process time
+            m_sdrDaemonSinkThread->setTxDelay((int) (delay*1e6));
+        }
     }
 
     mutexLocker.unlock();
 
-    qDebug("SDRdaemonSinkOutput::applySettings: %s m_centerFrequency: %llu m_sampleRate: %llu m_log2Interp: %d m_txDelay: %d m_nbFECBlocks: %d",
+    qDebug("SDRdaemonSinkOutput::applySettings: %s m_centerFrequency: %llu m_sampleRate: %llu m_log2Interp: %d m_txDelay: %f m_nbFECBlocks: %d",
             forwardChange ? "forward change" : "",
             m_settings.m_centerFrequency,
             m_settings.m_sampleRate,
diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.cpp b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.cpp
index e757b1397..65e814510 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.cpp
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.cpp
@@ -27,7 +27,7 @@ void SDRdaemonSinkSettings::resetToDefaults()
     m_centerFrequency = 435000*1000;
     m_sampleRate = 192000;
     m_log2Interp = 4;
-    m_txDelay = 300;
+    m_txDelay = 0.5;
     m_nbFECBlocks = 0;
     m_address = "127.0.0.1";
     m_dataPort = 9092;
@@ -41,7 +41,7 @@ QByteArray SDRdaemonSinkSettings::serialize() const
 
     s.writeU64(1, m_sampleRate);
     s.writeU32(2, m_log2Interp);
-    s.writeU32(3, m_txDelay);
+    s.writeFloat(3, m_txDelay);
     s.writeU32(4, m_nbFECBlocks);
     s.writeString(5, m_address);
     s.writeU32(6, m_dataPort);
@@ -66,7 +66,7 @@ bool SDRdaemonSinkSettings::deserialize(const QByteArray& data)
         quint32 uintval;
         d.readU64(1, &m_sampleRate, 48000);
         d.readU32(2, &m_log2Interp, 0);
-        d.readU32(3, &m_txDelay, 300);
+        d.readFloat(3, &m_txDelay, 0.5);
         d.readU32(4, &m_nbFECBlocks, 0);
         d.readString(5, &m_address, "127.0.0.1");
         d.readU32(6, &uintval, 9090);
diff --git a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.h b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.h
index 05d73e844..5f20970f2 100644
--- a/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.h
+++ b/plugins/samplesink/sdrdaemonsink/sdrdaemonsinksettings.h
@@ -23,7 +23,7 @@ struct SDRdaemonSinkSettings {
     quint64 m_centerFrequency;
     quint64 m_sampleRate;
     quint32 m_log2Interp;
-    quint32 m_txDelay;
+    float   m_txDelay;
     quint32 m_nbFECBlocks;
     QString m_address;
     quint16 m_dataPort;
diff --git a/plugins/samplesource/sdrdaemonfec/sdrdaemonfecgui.ui b/plugins/samplesource/sdrdaemonfec/sdrdaemonfecgui.ui
index cc19b66ea..cadf5a5c1 100644
--- a/plugins/samplesource/sdrdaemonfec/sdrdaemonfecgui.ui
+++ b/plugins/samplesource/sdrdaemonfec/sdrdaemonfecgui.ui
@@ -178,13 +178,6 @@
    </item>
    <item>
     <layout class="QHBoxLayout" name="gridLayout_corr">
-     <item>
-      <widget class="QLabel" name="label">
-       <property name="text">
-        <string>Auto Corr</string>
-       </property>
-      </widget>
-     </item>
      <item>
       <widget class="ButtonSwitch" name="dcOffset">
        <property name="toolTip">
@@ -218,6 +211,64 @@
        </property>
       </spacer>
      </item>
+     <item>
+      <widget class="QLabel" name="bufferLenSecsText">
+       <property name="sizePolicy">
+        <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+         <horstretch>0</horstretch>
+         <verstretch>0</verstretch>
+        </sizepolicy>
+       </property>
+       <property name="minimumSize">
+        <size>
+         <width>28</width>
+         <height>0</height>
+        </size>
+       </property>
+       <property name="toolTip">
+        <string>Buffer length in seconds</string>
+       </property>
+       <property name="text">
+        <string>00.0</string>
+       </property>
+       <property name="alignment">
+        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="Line" name="lineStream7">
+       <property name="orientation">
+        <enum>Qt::Vertical</enum>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QLabel" name="bufferRWBalanceText">
+       <property name="minimumSize">
+        <size>
+         <width>22</width>
+         <height>0</height>
+        </size>
+       </property>
+       <property name="toolTip">
+        <string>Main buffer read/write positions unbalance (%): positive means read leads</string>
+       </property>
+       <property name="text">
+        <string>-00</string>
+       </property>
+       <property name="alignment">
+        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="Line" name="lineStream2">
+       <property name="orientation">
+        <enum>Qt::Vertical</enum>
+       </property>
+      </widget>
+     </item>
      <item>
       <widget class="QLabel" name="absTimeText">
        <property name="enabled">
@@ -441,38 +492,6 @@
        </property>
       </widget>
      </item>
-     <item>
-      <widget class="QLabel" name="bufferLenSecsText">
-       <property name="sizePolicy">
-        <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
-         <horstretch>0</horstretch>
-         <verstretch>0</verstretch>
-        </sizepolicy>
-       </property>
-       <property name="minimumSize">
-        <size>
-         <width>28</width>
-         <height>0</height>
-        </size>
-       </property>
-       <property name="toolTip">
-        <string>Buffer length in seconds</string>
-       </property>
-       <property name="text">
-        <string>00.0</string>
-       </property>
-       <property name="alignment">
-        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="Line" name="lineStream7">
-       <property name="orientation">
-        <enum>Qt::Vertical</enum>
-       </property>
-      </widget>
-     </item>
      <item>
       <widget class="QLabel" name="nominalNbBlocksText">
        <property name="minimumSize">
@@ -492,32 +511,6 @@
        </property>
       </widget>
      </item>
-     <item>
-      <widget class="Line" name="lineStream2">
-       <property name="orientation">
-        <enum>Qt::Vertical</enum>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QLabel" name="bufferRWBalanceText">
-       <property name="minimumSize">
-        <size>
-         <width>22</width>
-         <height>0</height>
-        </size>
-       </property>
-       <property name="toolTip">
-        <string>Main buffer read/write positions unbalance (%): positive means read leads</string>
-       </property>
-       <property name="text">
-        <string>-00</string>
-       </property>
-       <property name="alignment">
-        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-       </property>
-      </widget>
-     </item>
      <item>
       <spacer name="horizontalSpacer">
        <property name="orientation">
@@ -570,9 +563,12 @@
        <property name="toolTip">
         <string>Local data connection IP address</string>
        </property>
-       <property name="text">
+       <property name="inputMask">
         <string>000.000.000.000</string>
        </property>
+       <property name="text">
+        <string>0.0.0.0</string>
+       </property>
        <property name="alignment">
         <set>Qt::AlignLeading|Qt::AlignLeft|Qt::AlignVCenter</set>
        </property>
@@ -599,9 +595,12 @@
        <property name="toolTip">
         <string>Local data connection port</string>
        </property>
-       <property name="text">
+       <property name="inputMask">
         <string>00000</string>
        </property>
+       <property name="text">
+        <string>0</string>
+       </property>
        <property name="alignment">
         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
        </property>
@@ -619,9 +618,12 @@
        <property name="toolTip">
         <string>Remote control port</string>
        </property>
-       <property name="text">
+       <property name="inputMask">
         <string>00000</string>
        </property>
+       <property name="text">
+        <string>0</string>
+       </property>
        <property name="alignment">
         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
        </property>