diff --git a/plugins/channeltx/modchirpchat/chirpchatmod.cpp b/plugins/channeltx/modchirpchat/chirpchatmod.cpp
index bf18f2871..fe07de693 100644
--- a/plugins/channeltx/modchirpchat/chirpchatmod.cpp
+++ b/plugins/channeltx/modchirpchat/chirpchatmod.cpp
@@ -362,7 +362,7 @@ void ChirpChatMod::applySettings(const ChirpChatModSettings& settings, bool forc
 
         if (getMessageQueueToGUI())
         {
-            MsgReportPayloadTime *rpt = MsgReportPayloadTime::create(m_currentPayloadTime);
+            MsgReportPayloadTime *rpt = MsgReportPayloadTime::create(m_currentPayloadTime, symbols.size());
             getMessageQueueToGUI()->push(rpt);
         }
     }
@@ -1095,7 +1095,7 @@ void ChirpChatMod::udpRx()
 
             if (getMessageQueueToGUI())
             {
-                MsgReportPayloadTime *rpt = MsgReportPayloadTime::create(m_currentPayloadTime);
+                MsgReportPayloadTime *rpt = MsgReportPayloadTime::create(m_currentPayloadTime, symbols.size());
                 getMessageQueueToGUI()->push(rpt);
             }
         }
diff --git a/plugins/channeltx/modchirpchat/chirpchatmod.h b/plugins/channeltx/modchirpchat/chirpchatmod.h
index 583118235..e2b990183 100644
--- a/plugins/channeltx/modchirpchat/chirpchatmod.h
+++ b/plugins/channeltx/modchirpchat/chirpchatmod.h
@@ -74,16 +74,19 @@ public:
 
     public:
         float getPayloadTimeMs() const { return m_timeMs; }
-        static MsgReportPayloadTime* create(float timeMs) {
-            return new MsgReportPayloadTime(timeMs);
+        std::size_t getNbSymbols() const { return m_nbSymbols; }
+        static MsgReportPayloadTime* create(float timeMs, std::size_t nbSymbols) {
+            return new MsgReportPayloadTime(timeMs, nbSymbols);
         }
 
     private:
         float m_timeMs; //!< time in milliseconds
+        std::size_t m_nbSymbols; //!< number of symbols
 
-        MsgReportPayloadTime(float timeMs) :
+        MsgReportPayloadTime(float timeMs, std::size_t nbSymbols) :
             Message(),
-            m_timeMs(timeMs)
+            m_timeMs(timeMs),
+            m_nbSymbols(nbSymbols)
         {}
     };
 
diff --git a/plugins/channeltx/modchirpchat/chirpchatmodgui.cpp b/plugins/channeltx/modchirpchat/chirpchatmodgui.cpp
index f7215e70d..29fa32f64 100644
--- a/plugins/channeltx/modchirpchat/chirpchatmodgui.cpp
+++ b/plugins/channeltx/modchirpchat/chirpchatmodgui.cpp
@@ -97,6 +97,7 @@ bool ChirpChatModGUI::handleMessage(const Message& message)
         fourthsChirps += m_settings.hasSyncWord() ? 8 : 0;
         fourthsChirps += m_settings.getNbSFDFourths();
         float controlMs = fourthsChirps * fourthsMs; // preamble + sync word + SFD
+        ui->timeMessageLengthText->setText(tr("%1").arg(rpt.getNbSymbols()));
         ui->timePayloadText->setText(tr("%1 ms").arg(QString::number(rpt.getPayloadTimeMs(), 'f', 0)));
         ui->timeTotalText->setText(tr("%1 ms").arg(QString::number(rpt.getPayloadTimeMs() + controlMs, 'f', 0)));
         ui->timeSymbolText->setText(tr("%1 ms").arg(QString::number(4.0*fourthsMs, 'f', 1)));
diff --git a/plugins/channeltx/modchirpchat/chirpchatmodgui.ui b/plugins/channeltx/modchirpchat/chirpchatmodgui.ui
index feb0f9db1..03915bf8e 100644
--- a/plugins/channeltx/modchirpchat/chirpchatmodgui.ui
+++ b/plugins/channeltx/modchirpchat/chirpchatmodgui.ui
@@ -722,12 +722,12 @@
        </widget>
       </item>
       <item>
-       <widget class="QLineEdit" name="report">
+       <widget class="QLineEdit" name="myLocator">
         <property name="focusPolicy">
          <enum>Qt::ClickFocus</enum>
         </property>
         <property name="toolTip">
-         <string>Report to callee</string>
+         <string>Caller QRA locator</string>
         </property>
         <property name="text">
          <string/>
@@ -751,12 +751,12 @@
        </widget>
       </item>
       <item>
-       <widget class="QLineEdit" name="myLocator">
+       <widget class="QLineEdit" name="report">
         <property name="focusPolicy">
          <enum>Qt::ClickFocus</enum>
         </property>
         <property name="toolTip">
-         <string>Caller QRA locator</string>
+         <string>Report to callee</string>
         </property>
         <property name="text">
          <string/>
@@ -1028,6 +1028,23 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QLabel" name="timeMessageLengthLabel">
+        <property name="text">
+         <string>ML</string>
+        </property>
+        <property name="alignment">
+         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="timeMessageLengthText">
+        <property name="text">
+         <string>000</string>
+        </property>
+       </widget>
+      </item>
       <item>
        <spacer name="horizontalSpacer_6">
         <property name="orientation">
diff --git a/plugins/samplemimo/audiocatsiso/audiocatoutputworker.cpp b/plugins/samplemimo/audiocatsiso/audiocatoutputworker.cpp
index 963cc1446..8f23521bf 100644
--- a/plugins/samplemimo/audiocatsiso/audiocatoutputworker.cpp
+++ b/plugins/samplemimo/audiocatsiso/audiocatoutputworker.cpp
@@ -25,7 +25,7 @@
 
 #include "audiocatoutputworker.h"
 
-#define AUDIOOUTPUT_THROTTLE_MS 50
+#define AUDIOOUTPUT_THROTTLE_MS 100
 
 AudioCATOutputWorker::AudioCATOutputWorker(SampleMOFifo* sampleFifo, AudioFifo *fifo, QObject* parent) :
     QObject(parent),
@@ -41,7 +41,7 @@ AudioCATOutputWorker::AudioCATOutputWorker(SampleMOFifo* sampleFifo, AudioFifo *
     m_sampleFifo(sampleFifo),
     m_audioFifo(fifo)
 {
-    m_audioBuffer.resize(1<<15);
+    m_audioBuffer.resize(12000);
     m_audioBufferFill = 0;
     setSamplerate(48000);
 }
diff --git a/plugins/samplemimo/audiocatsiso/audiocatsiso.cpp b/plugins/samplemimo/audiocatsiso/audiocatsiso.cpp
index ca580280b..4347d6936 100644
--- a/plugins/samplemimo/audiocatsiso/audiocatsiso.cpp
+++ b/plugins/samplemimo/audiocatsiso/audiocatsiso.cpp
@@ -46,7 +46,7 @@ MESSAGE_CLASS_DEFINITION(AudioCATSISO::MsgStartStop, Message)
 AudioCATSISO::AudioCATSISO(DeviceAPI *deviceAPI) :
     m_deviceAPI(deviceAPI),
     m_inputFifo(48000),
-    m_outputFifo(48000),
+    m_outputFifo(24000),
 	m_settings(),
     m_inputWorker(nullptr),
     m_outputWorker(nullptr),
diff --git a/plugins/samplemimo/audiocatsiso/audiocatsisogui.cpp b/plugins/samplemimo/audiocatsiso/audiocatsisogui.cpp
index 918c868f4..bb0b23098 100644
--- a/plugins/samplemimo/audiocatsiso/audiocatsisogui.cpp
+++ b/plugins/samplemimo/audiocatsiso/audiocatsisogui.cpp
@@ -257,6 +257,14 @@ void AudioCATSISOGUI::on_streamLock_toggled(bool checked)
     }
 }
 
+void AudioCATSISOGUI::on_freqRxToTx_clicked()
+{
+    m_settings.m_txCenterFrequency = m_settings.m_rxCenterFrequency;
+    displayFrequency();
+    m_settingsKeys.append("txCenterFrequency");
+    sendSettings();
+}
+
 void AudioCATSISOGUI::on_centerFrequency_changed(quint64 value)
 {
     if (m_rxElseTx)
@@ -771,7 +779,8 @@ void AudioCATSISOGUI::makeUIConnections()
 	QObject::connect(ui->streamSide, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &AudioCATSISOGUI::on_streamSide_currentIndexChanged);
     QObject::connect(ui->spectrumSide, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &AudioCATSISOGUI::on_spectrumSide_currentIndexChanged);
     QObject::connect(ui->streamLock, &QToolButton::toggled, this, &AudioCATSISOGUI::on_streamLock_toggled);
-	QObject::connect(ui->startStop, &ButtonSwitch::toggled, this, &AudioCATSISOGUI::on_startStop_toggled);
+	QObject::connect(ui->freqRxToTx, &QPushButton::clicked, this, &AudioCATSISOGUI::on_freqRxToTx_clicked);
+    QObject::connect(ui->startStop, &ButtonSwitch::toggled, this, &AudioCATSISOGUI::on_startStop_toggled);
 	QObject::connect(ui->ptt, &ButtonSwitch::toggled, this, &AudioCATSISOGUI::on_ptt_toggled);
 	QObject::connect(ui->catConnect, &ButtonSwitch::toggled, this, &AudioCATSISOGUI::on_catConnect_toggled);
     QObject::connect(ui->centerFrequency, &ValueDial::changed, this, &AudioCATSISOGUI::on_centerFrequency_changed);
diff --git a/plugins/samplemimo/audiocatsiso/audiocatsisogui.h b/plugins/samplemimo/audiocatsiso/audiocatsisogui.h
index c750714a8..a8a300140 100644
--- a/plugins/samplemimo/audiocatsiso/audiocatsisogui.h
+++ b/plugins/samplemimo/audiocatsiso/audiocatsisogui.h
@@ -89,6 +89,7 @@ private slots:
     void on_streamSide_currentIndexChanged(int index);
     void on_spectrumSide_currentIndexChanged(int index);
     void on_streamLock_toggled(bool checked);
+    void on_freqRxToTx_clicked();
 	void on_startStop_toggled(bool checked);
     void on_ptt_toggled(bool checked);
     void on_pttSpectrumLinkToggled(bool checked);
diff --git a/plugins/samplemimo/audiocatsiso/audiocatsisogui.ui b/plugins/samplemimo/audiocatsiso/audiocatsisogui.ui
index 4fc028312..7c2bf51d4 100644
--- a/plugins/samplemimo/audiocatsiso/audiocatsisogui.ui
+++ b/plugins/samplemimo/audiocatsiso/audiocatsisogui.ui
@@ -160,6 +160,23 @@
        </property>
       </widget>
      </item>
+     <item>
+      <widget class="QPushButton" name="freqRxToTx">
+       <property name="toolTip">
+        <string>Send Rx frequency to Tx</string>
+       </property>
+       <property name="text">
+        <string/>
+       </property>
+       <property name="icon">
+        <iconset resource="../../../sdrgui/resources/res.qrc">
+         <normaloff>:/arrow_left.png</normaloff>:/arrow_left.png</iconset>
+       </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
+      </widget>
+     </item>
      <item>
       <widget class="ButtonSwitch" name="txEnable">
        <property name="toolTip">