diff --git a/plugins/samplesink/hackrfoutput/hackrfoutput.cpp b/plugins/samplesink/hackrfoutput/hackrfoutput.cpp
index 4220ca1e0..3ec4170ef 100644
--- a/plugins/samplesink/hackrfoutput/hackrfoutput.cpp
+++ b/plugins/samplesink/hackrfoutput/hackrfoutput.cpp
@@ -187,11 +187,21 @@ bool HackRFOutput::handleMessage(const Message& message)
 
 		if (!success)
 		{
-			qDebug("HackRFOutput::handleMessage: config error");
+			qDebug("HackRFOutput::handleMessage: MsgConfigureHackRF: config error");
 		}
 
 		return true;
 	}
+    else if (DeviceHackRFShared::MsgConfigureFrequencyDelta::match(message))
+    {
+        DeviceHackRFShared::MsgConfigureFrequencyDelta& conf = (DeviceHackRFShared::MsgConfigureFrequencyDelta&) message;
+        HackRFOutputSettings newSettings = m_settings;
+        newSettings.m_centerFrequency = m_settings.m_centerFrequency + conf.getFrequencyDelta();
+        qDebug() << "HackRFOutput::handleMessage: DeviceHackRFShared::MsgConfigureFrequencyDelta: newFreq: " << newSettings.m_centerFrequency;
+        applySettings(newSettings, false);
+
+        return true;
+    }
 	else
 	{
 		return false;
diff --git a/plugins/samplesink/hackrfoutput/hackrfoutputgui.cpp b/plugins/samplesink/hackrfoutput/hackrfoutputgui.cpp
index 0902d038c..8d342ab92 100644
--- a/plugins/samplesink/hackrfoutput/hackrfoutputgui.cpp
+++ b/plugins/samplesink/hackrfoutput/hackrfoutputgui.cpp
@@ -38,7 +38,8 @@ HackRFOutputGui::HackRFOutputGui(DeviceSinkAPI *deviceAPI, QWidget* parent) :
 	m_deviceAPI(deviceAPI),
 	m_settings(),
 	m_deviceSampleSink(0),
-	m_lastEngineState((DSPDeviceSinkEngine::State)-1)
+	m_lastEngineState((DSPDeviceSinkEngine::State)-1),
+	m_doApplySettings(true)
 {
     m_deviceSampleSink = (HackRFOutput*) m_deviceAPI->getSampleSink();
 
@@ -55,6 +56,7 @@ HackRFOutputGui::HackRFOutputGui(DeviceSinkAPI *deviceAPI, QWidget* parent) :
 
 	displaySettings();
 	displayBandwidths();
+	sendSettings();
 
 	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);
 }
@@ -118,6 +120,12 @@ bool HackRFOutputGui::deserialize(const QByteArray& data)
 	}
 }
 
+void HackRFOutputGui::blockApplySettings(bool block)
+{
+    m_doApplySettings = !block;
+}
+
+
 bool HackRFOutputGui::handleMessage(const Message& message)
 {
     if (HackRFOutput::MsgReportHackRF::match(message))
@@ -151,8 +159,10 @@ void HackRFOutputGui::handleInputMessages()
         }
         else if (DeviceHackRFShared::MsgConfigureFrequencyDelta::match(*message))
         {
+            blockApplySettings(true);
             DeviceHackRFShared::MsgConfigureFrequencyDelta* deltaMsg = (DeviceHackRFShared::MsgConfigureFrequencyDelta *) message;
             ui->centerFrequency->setValue(ui->centerFrequency->getValue() + (deltaMsg->getFrequencyDelta()/1000));
+            blockApplySettings(false);
 
             delete message;
         }
@@ -175,6 +185,7 @@ void HackRFOutputGui::updateSampleRateAndFrequency()
 
 void HackRFOutputGui::displaySettings()
 {
+    blockApplySettings(true);
 	ui->centerFrequency->setValue(m_settings.m_centerFrequency / 1000);
 
 	ui->LOppm->setValue(m_settings.m_LOppmTenths);
@@ -192,10 +203,12 @@ void HackRFOutputGui::displaySettings()
 
     unsigned int bandwidthIndex = HackRFBandwidths::getBandwidthIndex(m_settings.m_bandwidth/1000);
 	ui->bbFilter->setCurrentIndex(bandwidthIndex);
+	blockApplySettings(false);
 }
 
 void HackRFOutputGui::displayBandwidths()
 {
+    blockApplySettings(true);
 	unsigned int savedIndex = HackRFBandwidths::getBandwidthIndex(m_settings.m_bandwidth/1000);
 	ui->bbFilter->blockSignals(true);
 	ui->bbFilter->clear();
@@ -215,6 +228,7 @@ void HackRFOutputGui::displayBandwidths()
 	{
 		ui->bbFilter->setCurrentIndex((int) HackRFBandwidths::m_nb_bw-1);
 	}
+	blockApplySettings(false);
 }
 
 void HackRFOutputGui::sendSettings()
@@ -305,10 +319,13 @@ void HackRFOutputGui::on_startStop_toggled(bool checked)
 
 void HackRFOutputGui::updateHardware()
 {
-	qDebug() << "HackRFOutputGui::updateHardware";
-	HackRFOutput::MsgConfigureHackRF* message = HackRFOutput::MsgConfigureHackRF::create(m_settings);
-    m_deviceSampleSink->getInputMessageQueue()->push(message);
-	m_updateTimer.stop();
+    if (m_doApplySettings)
+    {
+        qDebug() << "HackRFOutputGui::updateHardware";
+        HackRFOutput::MsgConfigureHackRF* message = HackRFOutput::MsgConfigureHackRF::create(m_settings);
+        m_deviceSampleSink->getInputMessageQueue()->push(message);
+        m_updateTimer.stop();
+    }
 }
 
 void HackRFOutputGui::updateStatus()
diff --git a/plugins/samplesink/hackrfoutput/hackrfoutputgui.h b/plugins/samplesink/hackrfoutput/hackrfoutputgui.h
index e51a63aed..5c62c7e25 100644
--- a/plugins/samplesink/hackrfoutput/hackrfoutputgui.h
+++ b/plugins/samplesink/hackrfoutput/hackrfoutputgui.h
@@ -73,11 +73,13 @@ private:
     quint64 m_deviceCenterFrequency; //!< Center frequency in device
 	int m_lastEngineState;
 	MessageQueue m_inputMessageQueue;
+    bool m_doApplySettings;
 
 	void displaySettings();
 	void displayBandwidths();
 	void sendSettings();
     void updateSampleRateAndFrequency();
+    void blockApplySettings(bool block);
 
 private slots:
     void handleInputMessages();
diff --git a/plugins/samplesource/hackrfinput/hackrfinput.cpp b/plugins/samplesource/hackrfinput/hackrfinput.cpp
index 8406a7054..768e5aff8 100644
--- a/plugins/samplesource/hackrfinput/hackrfinput.cpp
+++ b/plugins/samplesource/hackrfinput/hackrfinput.cpp
@@ -312,13 +312,16 @@ bool HackRFInput::applySettings(const HackRFInputSettings& settings, bool force)
 	    if (m_settings.m_linkTxFrequency && (m_deviceAPI->getSinkBuddies().size() > 0))
 	    {
 	        DeviceSinkAPI *buddy = m_deviceAPI->getSinkBuddies()[0];
+            DeviceHackRFShared::MsgConfigureFrequencyDelta *deltaMsg = DeviceHackRFShared::MsgConfigureFrequencyDelta::create(
+                    settings.m_centerFrequency - m_settings.m_centerFrequency);
 
 	        if (buddy->getSampleSinkGUIMessageQueue())
 	        {
-                DeviceHackRFShared::MsgConfigureFrequencyDelta *deltaMsg = DeviceHackRFShared::MsgConfigureFrequencyDelta::create(settings.m_centerFrequency - m_settings.m_centerFrequency);
-                buddy->getSampleSinkGUIMessageQueue()->push(deltaMsg);
+	            DeviceHackRFShared::MsgConfigureFrequencyDelta *deltaMsgToGUI = new DeviceHackRFShared::MsgConfigureFrequencyDelta(*deltaMsg);
+                buddy->getSampleSinkGUIMessageQueue()->push(deltaMsgToGUI);
 	        }
-	        // TODO: send to buddy sample sink
+
+	        buddy->getSampleSinkInputMessageQueue()->push(deltaMsg);
 	    }
 	}