diff --git a/CMakeLists.txt b/CMakeLists.txt
index cb3cdf8e2..79355857e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -278,6 +278,7 @@ set (wsjt_FSRCS
   lib/decjt9.f90
   lib/deep4.f90
   lib/deg2grid.f90
+  lib/degrade_snr.f90
   lib/demod64a.f90
   lib/determ.f90
   lib/downsam9.f90
diff --git a/Configuration.cpp b/Configuration.cpp
index 668188a87..c03b34a3a 100644
--- a/Configuration.cpp
+++ b/Configuration.cpp
@@ -357,7 +357,6 @@ public:
   Q_SLOT void reject () override;
   Q_SLOT void done (int) override;
 
-
 private:
   typedef QList<QAudioDeviceInfo> AudioDevices;
 
@@ -521,6 +520,7 @@ private:
   qint32 id_interval_;
   qint32 ntrials_;
   qint32 aggressive_;
+  double degrade_;
   bool id_after_73_;
   bool tx_QSY_allowed_;
   bool spot_to_psk_reporter_;
@@ -601,6 +601,7 @@ QFont Configuration::decoded_text_font () const {return m_->decoded_text_font_;}
 qint32 Configuration::id_interval () const {return m_->id_interval_;}
 qint32 Configuration::ntrials() const {return m_->ntrials_;}
 qint32 Configuration::aggressive() const {return m_->aggressive_;}
+double Configuration::degrade() const {return m_->degrade_;}
 bool Configuration::id_after_73 () const {return m_->id_after_73_;}
 bool Configuration::tx_QSY_allowed () const {return m_->tx_QSY_allowed_;}
 bool Configuration::spot_to_psk_reporter () const {return m_->spot_to_psk_reporter_;}
@@ -1026,6 +1027,7 @@ void Configuration::impl::initialize_models ()
   ui_->CW_id_interval_spin_box->setValue (id_interval_);  
   ui_->sbNtrials->setValue (ntrials_);
   ui_->sbAggressive->setValue (aggressive_);
+  ui_->sbDegrade->setValue (degrade_);
   ui_->PTT_method_button_group->button (rig_params_.ptt_type)->setChecked (true);
   ui_->save_path_display_label->setText (save_directory_.absolutePath ());
   ui_->azel_path_display_label->setText (azel_directory_.absolutePath ());
@@ -1158,7 +1160,6 @@ void Configuration::impl::read_settings ()
   id_interval_ = settings_->value ("IDint", 0).toInt ();
   ntrials_ = settings_->value ("nTrials", 6).toInt ();
   aggressive_ = settings_->value ("Aggressive", 0).toInt ();
-
   save_directory_ = settings_->value ("SaveDir", default_save_directory_.absolutePath ()).toString ();
   azel_directory_ = settings_->value ("AzElDir", default_azel_directory_.absolutePath ()).toString ();
 
@@ -1741,6 +1742,7 @@ void Configuration::impl::accept ()
   id_interval_ = ui_->CW_id_interval_spin_box->value ();
   ntrials_ = ui_->sbNtrials->value ();
   aggressive_ = ui_->sbAggressive->value ();
+  degrade_ = ui_->sbDegrade->value ();
   id_after_73_ = ui_->CW_id_after_73_check_box->isChecked ();
   tx_QSY_allowed_ = ui_->tx_QSY_check_box->isChecked ();
   monitor_off_at_startup_ = ui_->monitor_off_check_box->isChecked ();
diff --git a/Configuration.hpp b/Configuration.hpp
index e441fa47e..b011d5cf5 100644
--- a/Configuration.hpp
+++ b/Configuration.hpp
@@ -93,6 +93,7 @@ public:
   qint32 id_interval () const;
   qint32 ntrials() const;
   qint32 aggressive() const;
+  double degrade() const;
   bool id_after_73 () const;
   bool tx_QSY_allowed () const;
   bool spot_to_psk_reporter () const;
diff --git a/Configuration.ui b/Configuration.ui
index e7b3123bf..11284cbe1 100644
--- a/Configuration.ui
+++ b/Configuration.ui
@@ -20,7 +20,7 @@
       <string>Select tab to change configuration parameters.</string>
      </property>
      <property name="currentIndex">
-      <number>0</number>
+      <number>7</number>
      </property>
      <widget class="QWidget" name="general_tab">
       <attribute name="title">
@@ -2127,7 +2127,7 @@ Right click for insert and delete options.</string>
       <attribute name="title">
        <string>Advanced</string>
       </attribute>
-      <layout class="QGridLayout" name="gridLayout_15">
+      <layout class="QGridLayout" name="gridLayout_9">
        <item row="0" column="0">
         <widget class="QGroupBox" name="groupBox_5">
          <property name="toolTip">
@@ -2268,6 +2268,33 @@ Right click for insert and delete options.</string>
               </property>
              </widget>
             </item>
+            <item row="1" column="0" colspan="2">
+             <layout class="QHBoxLayout" name="horizontalLayout_12">
+              <item>
+               <widget class="QLabel" name="label_3">
+                <property name="text">
+                 <string>Degrade S/N of .wav file: </string>
+                </property>
+                <property name="buddy">
+                 <cstring>sbDegrade</cstring>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QDoubleSpinBox" name="sbDegrade">
+                <property name="suffix">
+                 <string> dB</string>
+                </property>
+                <property name="decimals">
+                 <number>1</number>
+                </property>
+                <property name="singleStep">
+                 <double>0.100000000000000</double>
+                </property>
+               </widget>
+              </item>
+             </layout>
+            </item>
            </layout>
           </item>
          </layout>
@@ -2286,7 +2313,7 @@ Right click for insert and delete options.</string>
          </property>
         </spacer>
        </item>
-       <item row="1" column="0" colspan="2">
+       <item row="1" column="0">
         <spacer name="verticalSpacer_8">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
@@ -2468,12 +2495,12 @@ soundcard changes</string>
   </connection>
  </connections>
  <buttongroups>
-  <buttongroup name="CAT_handshake_button_group"/>
   <buttongroup name="split_mode_button_group"/>
-  <buttongroup name="CAT_data_bits_button_group"/>
-  <buttongroup name="TX_audio_source_button_group"/>
   <buttongroup name="TX_mode_button_group"/>
-  <buttongroup name="CAT_stop_bits_button_group"/>
   <buttongroup name="PTT_method_button_group"/>
+  <buttongroup name="TX_audio_source_button_group"/>
+  <buttongroup name="CAT_stop_bits_button_group"/>
+  <buttongroup name="CAT_handshake_button_group"/>
+  <buttongroup name="CAT_data_bits_button_group"/>
  </buttongroups>
 </ui>
diff --git a/lib/fqso_first.f90 b/lib/fqso_first.f90
new file mode 100644
index 000000000..d75dac9b8
--- /dev/null
+++ b/lib/fqso_first.f90
@@ -0,0 +1,31 @@
+subroutine fqso_first(nfqso,ntol,ca,ncand)
+
+! If a candidate was found within +/- ntol of nfqso, move it into ca(1).
+
+  type candidate
+     real freq
+     real dt
+     real sync
+  end type candidate
+  type(candidate) ca(300),cb
+
+  dmin=1.e30
+  i0=0
+  do i=1,ncand
+     d=abs(ca(i)%freq-nfqso)
+     if(d.lt.dmin) then
+        i0=i
+        dmin=d
+     endif
+  enddo
+
+  if(dmin.lt.float(ntol)) then
+     cb=ca(i0)
+     do i=i0,2,-1
+        ca(i)=ca(i-1)
+     enddo
+     ca(1)=cb
+  endif
+
+  return
+end subroutine fqso_first
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 1a68e2a7f..fabc9731e 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1531,6 +1531,9 @@ void MainWindow::diskDat()                                   //diskDat()
   int kstep=3456;
   m_diskData=true;
 
+  float db=m_config.degrade();
+  if(db > 0.0) degrade_snr_(jt9com_.d2,&jt9com_.kin,&db);
+
   for(int n=1; n<=m_hsymStop; n++) {                      // Do the waterfall spectra
     k=(n+1)*kstep;
     if(k > jt9com_.kin) break;
diff --git a/mainwindow.h b/mainwindow.h
index 91a02f5e5..7b39dc523 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -604,6 +604,7 @@ extern "C" {
                 float* width);
 
   void fast_decode_(short id2[], int narg[], char msg[], int len);
+  void degrade_snr_(short d2[], int* n, float* db);
 }
 
 #endif // MAINWINDOW_H