diff --git a/plugins/channelrx/demodfreedv/freedvdemod.cpp b/plugins/channelrx/demodfreedv/freedvdemod.cpp
index 9a47dfa9b..dee62ae3b 100644
--- a/plugins/channelrx/demodfreedv/freedvdemod.cpp
+++ b/plugins/channelrx/demodfreedv/freedvdemod.cpp
@@ -611,6 +611,10 @@ void FreeDVDemod::applyFreeDVMode(FreeDVDemodSettings::FreeDVMode mode)
         freedv_set_ext_vco(m_freeDV, 0);
         freedv_set_sync(m_freeDV, manualsync);
 
+        freedv_set_callback_txt(m_freeDV, nullptr, nullptr, nullptr);
+        freedv_set_callback_protocol(m_freeDV, nullptr, nullptr, nullptr);
+        freedv_set_callback_data(m_freeDV, nullptr, nullptr, nullptr);
+
         int nSpeechSamples = freedv_get_n_speech_samples(m_freeDV);
         int nMaxModemSamples = freedv_get_n_max_modem_samples(m_freeDV);
         int Fs = freedv_get_modem_sample_rate(m_freeDV);
diff --git a/plugins/channelrx/demodfreedv/freedvdemodgui.ui b/plugins/channelrx/demodfreedv/freedvdemodgui.ui
index cfa9699ca..aaf1f1a2f 100644
--- a/plugins/channelrx/demodfreedv/freedvdemodgui.ui
+++ b/plugins/channelrx/demodfreedv/freedvdemodgui.ui
@@ -259,6 +259,9 @@
           <pointsize>8</pointsize>
          </font>
         </property>
+        <property name="toolTip">
+         <string>Channel power</string>
+        </property>
        </widget>
       </item>
      </layout>
@@ -320,7 +323,7 @@
          </size>
         </property>
         <property name="toolTip">
-         <string>Modem input volume</string>
+         <string>Modem input volume level</string>
         </property>
         <property name="text">
          <string>2.0</string>
@@ -350,6 +353,9 @@
           <pointsize>8</pointsize>
          </font>
         </property>
+        <property name="toolTip">
+         <string>Modem input volume</string>
+        </property>
        </widget>
       </item>
       <item>
@@ -373,6 +379,9 @@
           <height>24</height>
          </size>
         </property>
+        <property name="toolTip">
+         <string>Audio output volume control</string>
+        </property>
         <property name="maximum">
          <number>99</number>
         </property>
@@ -389,6 +398,9 @@
           <height>16777215</height>
          </size>
         </property>
+        <property name="toolTip">
+         <string>Audio output volume level </string>
+        </property>
         <property name="text">
          <string>2.0</string>
         </property>
@@ -600,7 +612,7 @@
       <item>
        <widget class="QSlider" name="spanLog2">
         <property name="toolTip">
-         <string>Demod frequency span</string>
+         <string>Spectrum display frequency span</string>
         </property>
         <property name="minimum">
          <number>0</number>
@@ -636,6 +648,9 @@
           <height>16777215</height>
          </size>
         </property>
+        <property name="toolTip">
+         <string>Spectrum display frequency span (kHz)</string>
+        </property>
         <property name="text">
          <string>6.0k</string>
         </property>
diff --git a/plugins/channeltx/modfreedv/freedvmod.cpp b/plugins/channeltx/modfreedv/freedvmod.cpp
index ef209b971..dacafa678 100644
--- a/plugins/channeltx/modfreedv/freedvmod.cpp
+++ b/plugins/channeltx/modfreedv/freedvmod.cpp
@@ -691,6 +691,10 @@ void FreeDVMod::applyFreeDVMode(FreeDVModSettings::FreeDVMode mode)
         freedv_set_tx_bpf(m_freeDV, 1);
         freedv_set_ext_vco(m_freeDV, 0);
 
+        freedv_set_callback_txt(m_freeDV, nullptr, nullptr, nullptr);
+        freedv_set_callback_protocol(m_freeDV, nullptr, nullptr, nullptr);
+        freedv_set_callback_data(m_freeDV, nullptr, nullptr, nullptr);
+
         int nSpeechSamples = freedv_get_n_speech_samples(m_freeDV);
         int nNomModemSamples = freedv_get_n_nom_modem_samples(m_freeDV);
         int Fs = freedv_get_modem_sample_rate(m_freeDV);