#536 Add Bias-T support for Airspy, Airspy HF and Funcube Dongles. (#2599)

Co-authored-by: denny <dennis.sheirer@gmail.com>

src/main/java/io/github/dsheirer/source/tuner/airspy/AirspyTunerConfiguration.java

@@ -32,6 +32,7 @@ public class AirspyTunerConfiguration extends TunerConfiguration
     private int mLNAGain = AirspyTunerController.LNA_GAIN_DEFAULT;
     private boolean mMixerAGC = false;
     private boolean mLNAAGC = false;
+    private boolean mBiasT = false;
 
     /**
      * Default constructor for JAXB
@@ -129,4 +130,15 @@ public class AirspyTunerConfiguration extends TunerConfiguration
     {
         mLNAAGC = enabled;
     }
+
+    @JacksonXmlProperty(isAttribute = true, localName = "bias_t")
+    public boolean isBiasT()
+    {
+        return mBiasT;
+    }
+
+    public void setBiasT(boolean enabled)
+    {
+        mBiasT = enabled;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/airspy/AirspyTunerController.java

@@ -183,13 +183,22 @@ public class AirspyTunerController extends TunerController
     }
 
     /**
-     * Closes the device, which also stops streaming.
+     * Turns off the bias-T and closes the device, which also stops streaming.
      * @param device to close, or null
      */
     private static void closeDevice(AirspyDevice device)
     {
         if(device != null)
         {
+            try
+            {
+                device.setBiasTee(false);
+            }
+            catch(AirspyException | RuntimeException e)
+            {
+                mLog.warn("Error turning off Airspy bias-T before closing the device - " + e.getMessage());
+            }
+
             try
             {
                 device.close();
@@ -462,6 +471,7 @@ public class AirspyTunerController extends TunerController
                 setLNAGain(config.getLNAGain());
                 setMixerAGC(config.isMixerAGC());
                 setLNAAGC(config.isLNAAGC());
+                setBiasT(config.isBiasT());
 
                 //Set the gain mode last, so custom values are already set, and linearity and sensitivity modes will
                 //automatically override the custom values.
@@ -620,6 +630,17 @@ public class AirspyTunerController extends TunerController
         execute(device -> device.setLnaAgc(enabled));
     }
 
+    /**
+     * Enables/disables the Bias-T (RF bias tee) power output for active antennas
+     *
+     * @param enabled true to enable Bias-T, false to disable
+     * @throws SourceException on error
+     */
+    public void setBiasT(boolean enabled) throws SourceException
+    {
+        execute(device -> device.setBiasTee(enabled));
+    }
+
     public void setGain(Gain gain) throws SourceException
     {
         if(gain != Gain.CUSTOM)

src/main/java/io/github/dsheirer/source/tuner/airspy/AirspyTunerEditor.java

@@ -66,6 +66,7 @@ public class AirspyTunerEditor extends TunerEditor<AirspyTuner, AirspyTunerConfi
     private JLabel mMixerGainValueLabel;
     private JCheckBox mLNAAGCCheckBox;
     private JCheckBox mMixerAGCCheckBox;
+    private JCheckBox mBiasTCheckBox;
 
     /**
      * Constructs an instance
@@ -116,6 +117,8 @@ public class AirspyTunerEditor extends TunerEditor<AirspyTuner, AirspyTunerConfi
         getFrequencyPanel().updateControls();
         getSampleRateCombo().setEnabled(hasTuner() && !getTuner().getTunerController().isLockedSampleRate());
         getTunerInfoButton().setEnabled(hasTuner());
+        getBiasTCheckBox().setEnabled(hasTuner());
+        getBiasTCheckBox().setSelected(hasTuner() && hasConfiguration() && getConfiguration().isBiasT());
         updateGainComponents((hasTuner() && hasConfiguration()) ? getConfiguration().getGain() : null);
 
         if(hasTuner())
@@ -159,6 +162,9 @@ public class AirspyTunerEditor extends TunerEditor<AirspyTuner, AirspyTunerConfi
         add(new JLabel("Sample Rate:"));
         add(getSampleRateCombo(), "wrap");
 
+        add(new JLabel(""));
+        add(getBiasTCheckBox(), "wrap");
+
         add(new JSeparator(), "span,growx,push");
         add(new JLabel("Gain Control"), "wrap");
 
@@ -182,6 +188,37 @@ public class AirspyTunerEditor extends TunerEditor<AirspyTuner, AirspyTunerConfi
         add(getLNAGainValueLabel());
     }
 
+    /**
+     * Checkbox to enable/disable Bias-T power for active antennas
+     */
+    private JCheckBox getBiasTCheckBox()
+    {
+        if(mBiasTCheckBox == null)
+        {
+            mBiasTCheckBox = new JCheckBox("Bias-T");
+            mBiasTCheckBox.setEnabled(false);
+            mBiasTCheckBox.setToolTipText("Enable Bias-T power output for active antennas");
+            mBiasTCheckBox.addActionListener(e ->
+            {
+                if(hasTuner() && !isLoading())
+                {
+                    try
+                    {
+                        getTuner().getController().setBiasT(mBiasTCheckBox.isSelected());
+                        save();
+                    }
+                    catch(Exception e1)
+                    {
+                        mLog.error("Error setting Bias-T", e1);
+                        JOptionPane.showMessageDialog(mBiasTCheckBox, "Couldn't set Bias-T: " + e1.getMessage());
+                    }
+                }
+            });
+        }
+
+        return mBiasTCheckBox;
+    }
+
     private JCheckBox getLNAAGCCheckBox()
     {
         if(mLNAAGCCheckBox == null)
@@ -607,6 +644,7 @@ public class AirspyTunerEditor extends TunerEditor<AirspyTuner, AirspyTunerConfi
             getConfiguration().setLNAGain(getLNAGainSlider().getValue());
             getConfiguration().setMixerAGC(getMixerAGCCheckBox().isSelected());
             getConfiguration().setLNAAGC(getLNAAGCCheckBox().isSelected());
+            getConfiguration().setBiasT(getBiasTCheckBox().isSelected());
             saveConfiguration();
         }
     }

src/main/java/io/github/dsheirer/source/tuner/airspy/hf/AirspyHfTunerConfiguration.java

@@ -32,6 +32,7 @@ public class AirspyHfTunerConfiguration extends TunerConfiguration
     private boolean mAgc;
     private boolean mLna;
     private int mAttenuation;
+    private boolean mBiasT;
 
     /**
      * Default constructor for JAXB
@@ -114,6 +115,25 @@ public class AirspyHfTunerConfiguration extends TunerConfiguration
         mLna = lna;
     }
 
+    /**
+     * Indicates if the Bias-T power output is enabled.  Only applies to devices whose firmware supports a bias-T.
+     * @return bias-T enabled state
+     */
+    @JacksonXmlProperty(isAttribute = true, localName = "bias_t")
+    public boolean isBiasT()
+    {
+        return mBiasT;
+    }
+
+    /**
+     * Sets the Bias-T power output enabled state
+     * @param enabled true to enable
+     */
+    public void setBiasT(boolean enabled)
+    {
+        mBiasT = enabled;
+    }
+
     /**
      * Attenuation setting.
      * @return attenuation setting index value.

src/main/java/io/github/dsheirer/source/tuner/airspy/hf/AirspyHfTunerController.java

@@ -73,6 +73,8 @@ public class AirspyHfTunerController extends TunerController
     private Attenuation mAttenuation = Attenuation.A0;
     private boolean mAgcEnabled;
     private boolean mLnaEnabled;
+    private boolean mBiasTSupported;
+    private boolean mBiasTEnabled;
     private volatile float mSamplesPerMillisecond = DEFAULT_SAMPLE_RATE.getSampleRate() / 1000.0f;
     private volatile int mBufferSampleCount = DEFAULT_BUFFER_SAMPLE_COUNT;
     private boolean mStreaming = false;
@@ -116,6 +118,8 @@ public class AirspyHfTunerController extends TunerController
 
         try
         {
+            mBiasTSupported = false;
+            mBiasTEnabled = false;
             mDevice = AirspyHf.open(serialNumber);
 
             BoardInfo boardInfo = mDevice.boardInfo();
@@ -139,6 +143,8 @@ public class AirspyHfTunerController extends TunerController
             }
 
             mAvailableSampleRates = Collections.unmodifiableList(sampleRates);
+            mBiasTSupported = detectBiasTSupport(mDevice);
+            mBiasTEnabled = false;
 
             //Force the sample rate to be applied, since the rate discovery leaves the device at the last rate.
             mCurrentSampleRate = null;
@@ -161,6 +167,7 @@ public class AirspyHfTunerController extends TunerController
     public void stop()
     {
         AirspyHfDevice device;
+        boolean biasTEnabled;
 
         getLock().lock();
 
@@ -169,6 +176,8 @@ public class AirspyHfTunerController extends TunerController
             device = mDevice;
             mDevice = null;
             mStreaming = false;
+            biasTEnabled = mBiasTEnabled;
+            mBiasTEnabled = false;
         }
         finally
         {
@@ -176,9 +185,58 @@ public class AirspyHfTunerController extends TunerController
         }
 
         mNativeBufferBroadcaster.clear();
+
+        if(device != null && biasTEnabled)
+        {
+            try
+            {
+                device.setBiasTee(0);
+            }
+            catch(AirspyHfException | RuntimeException e)
+            {
+                mLog.warn("Error turning off Airspy HF bias-T before closing the device - " + e.getMessage());
+            }
+        }
+
         closeDevice(device);
     }
 
+    /**
+     * Detects if the device firmware supports a bias-T.  Firmware without bias-T support rejects the bias-T commands.
+     * Some firmware (HF+ Discovery R5.0.1) rejects the bias-T count request, so this falls back to turning the bias-T
+     * off, which is a safe probe since the bias-T should be off at startup anyway.
+     * @param device to probe
+     * @return true if the device accepts bias-T commands
+     */
+    private static boolean detectBiasTSupport(AirspyHfDevice device)
+    {
+        try
+        {
+            if(device.biasTeeCount() > 0)
+            {
+                device.setBiasTee(0);
+                return true;
+            }
+
+            return false;
+        }
+        catch(AirspyHfException | RuntimeException e)
+        {
+            //Bias-T count not supported - fall through and probe with a bias-T off command.
+        }
+
+        try
+        {
+            device.setBiasTee(0);
+            return true;
+        }
+        catch(AirspyHfException | RuntimeException e)
+        {
+            mLog.debug("Airspy HF firmware doesn't support bias-T - " + e.getMessage());
+            return false;
+        }
+    }
+
     /**
      * Closes the device, which also stops streaming.
      * @param device to close, or null
@@ -448,6 +506,11 @@ public class AirspyHfTunerController extends TunerController
                 setLna(airspyConfig.isLna());
                 setAttenuation(airspyConfig.getAttenuation());
                 setAgc(airspyConfig.isAgc());
+
+                if(isBiasTSupported())
+                {
+                    setBiasT(airspyConfig.isBiasT());
+                }
             }
             catch(SourceException se)
             {
@@ -670,4 +733,38 @@ public class AirspyHfTunerController extends TunerController
         execute(device -> device.setAttenuationStep(attenuation.getValue()));
         mAttenuation = attenuation;
     }
+
+    /**
+     * Indicates if the device firmware supports a bias-T, available once the tuner is started.
+     * @return true if supported
+     */
+    public boolean isBiasTSupported()
+    {
+        return mBiasTSupported;
+    }
+
+    /**
+     * Indicates if the Bias-T power output is enabled.
+     * @return enabled state
+     */
+    public boolean getBiasT()
+    {
+        return mBiasTEnabled;
+    }
+
+    /**
+     * Enables/disables the Bias-T (RF bias tee) power output for active antennas
+     * @param enabled true to enable Bias-T, false to disable
+     * @throws SourceException if the device doesn't support a bias-T or there is an error
+     */
+    public void setBiasT(boolean enabled) throws SourceException
+    {
+        if(!mBiasTSupported)
+        {
+            throw new SourceException("Airspy HF firmware doesn't support bias-T");
+        }
+
+        execute(device -> device.setBiasTee(enabled ? 1 : 0));
+        mBiasTEnabled = enabled;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/airspy/hf/AirspyHfTunerEditor.java

@@ -46,6 +46,7 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
     private JComboBox<Attenuation> mAttenuationCombo;
     private JToggleButton mAgcToggleButton;
     private JToggleButton mLnaToggleButton;
+    private JToggleButton mBiasTToggleButton;
 
     /**
      * Constructs an instance
@@ -100,6 +101,7 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
         buttonPanel.setLayout(new MigLayout("insets 0", "[left]", ""));
         buttonPanel.add(getAgcToggleButton());
         buttonPanel.add(getLnaToggleButton());
+        buttonPanel.add(getBiasTToggleButton());
         add(new JLabel(" "));
         add(buttonPanel, "wrap");
 
@@ -125,6 +127,12 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
             getConfiguration().setAgc(getAgcToggleButton().isSelected());
             getConfiguration().setLna(getLnaToggleButton().isSelected());
 
+            //Only update bias-T when the device supports it, so the saved setting isn't lost on unsupported firmware.
+            if(getTuner().getController().isBiasTSupported())
+            {
+                getConfiguration().setBiasT(getBiasTToggleButton().isSelected());
+            }
+
             saveConfiguration();
         }
     }
@@ -158,6 +166,11 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
             getAgcToggleButton().setSelected(getTuner().getController().getAgc());
             getLnaToggleButton().setEnabled(true);
             getLnaToggleButton().setSelected(getTuner().getController().getLna());
+            boolean biasTSupported = getTuner().getController().isBiasTSupported();
+            getBiasTToggleButton().setEnabled(biasTSupported);
+            getBiasTToggleButton().setSelected(biasTSupported && getTuner().getController().getBiasT());
+            getBiasTToggleButton().setToolTipText(biasTSupported ? "Enable Bias-T power output for active antennas" :
+                    "Bias-T not supported by this device or firmware");
             getSampleRateCombo().setSelectedItem(getTuner().getController().getCurrentAirspySampleRate());
             getAttenuationCombo().setEnabled(!getTuner().getController().getAgc());
             getAttenuationCombo().setSelectedItem(getTuner().getController().getAttenuation());
@@ -169,6 +182,9 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
             getAgcToggleButton().setSelected(false);
             getLnaToggleButton().setEnabled(false);
             getLnaToggleButton().setSelected(false);
+            getBiasTToggleButton().setEnabled(false);
+            getBiasTToggleButton().setSelected(false);
+            getBiasTToggleButton().setToolTipText("No tuner available");
             getSampleRateCombo().setEnabled(false);
             getAttenuationCombo().setEnabled(false);
             getAttenuationCombo().setSelectedItem(Attenuation.A0);
@@ -344,4 +360,36 @@ public class AirspyHfTunerEditor extends TunerEditor<AirspyHfTuner,AirspyHfTuner
 
         return mLnaToggleButton;
     }
+
+    /**
+     * Bias-T toggle button, enabled only when the device firmware supports a bias-T.
+     */
+    private JToggleButton getBiasTToggleButton()
+    {
+        if(mBiasTToggleButton == null)
+        {
+            mBiasTToggleButton = new JToggleButton("Bias-T");
+            mBiasTToggleButton.setToolTipText("Enable Bias-T power output for active antennas");
+            mBiasTToggleButton.setEnabled(false);
+            mBiasTToggleButton.addActionListener(e -> {
+                if(hasTuner() && !isLoading())
+                {
+                    try
+                    {
+                        getTuner().getController().setBiasT(mBiasTToggleButton.isSelected());
+                        save();
+                    }
+                    catch(SourceException se)
+                    {
+                        mLog.error("Error setting Airspy HF Bias-T", se);
+                        mBiasTToggleButton.setSelected(getTuner().getController().getBiasT());
+                        JOptionPane.showMessageDialog(AirspyHfTunerEditor.this,
+                                "Airspy HF Tuner Controller - couldn't change Bias-T setting " + se.getLocalizedMessage());
+                    }
+                }
+            });
+        }
+
+        return mBiasTToggleButton;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/fcd/proV1/FCD1TunerConfiguration.java

@@ -35,6 +35,7 @@ public class FCD1TunerConfiguration extends TunerConfiguration
     private LNAGain mLNAGain = LNAGain.LNA_GAIN_PLUS_20_0;
     private LNAEnhance mLNAEnhance = LNAEnhance.LNA_ENHANCE_OFF;
     private MixerGain mMixerGain = MixerGain.MIXER_GAIN_PLUS_12_0;
+    private boolean mBiasT = false;
 
     /**
      * Default constructor for JAXB
@@ -132,4 +133,15 @@ public class FCD1TunerConfiguration extends TunerConfiguration
     {
         mGainCorrection = value;
     }
+
+    @JacksonXmlProperty(isAttribute = true, localName = "bias_t")
+    public boolean isBiasT()
+    {
+        return mBiasT;
+    }
+
+    public void setBiasT(boolean enabled)
+    {
+        mBiasT = enabled;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/fcd/proV1/FCD1TunerController.java

@@ -49,6 +49,7 @@ public class FCD1TunerController extends FCDTunerController
     private LNAGain mLNAGain;
     private LNAEnhance mLNAEnhance;
     private MixerGain mMixerGain;
+    private boolean mBiasTEnabled = false;
 
     /**
      * Constructs an instance
@@ -123,9 +124,61 @@ public class FCD1TunerController extends FCDTunerController
                 //Re-cast any usb exceptions as source exceptions
                 throw new SourceException("FCD 1 Controller error applying tuner config - " + e.getLocalizedMessage());
             }
+
+            //Apply the bias-T separately so that a bias-T error doesn't prevent the tuner from starting.
+            try
+            {
+                setBiasT(fcd1.isBiasT());
+            }
+            catch(SourceException se)
+            {
+                mLog.warn("FCD 1 Controller couldn't apply bias-T setting - " + se.getMessage());
+            }
         }
    }
 
+    /**
+     * Enables/disables the Bias-T (RF bias tee) power output for active antennas
+     *
+     * @param enabled true to enable Bias-T, false to disable
+     * @throws SourceException on error
+     */
+    public void setBiasT(boolean enabled) throws SourceException
+    {
+        try
+        {
+            send(FCDCommand.APP_SET_BIAS_TEE, enabled ? 1 : 0);
+            mBiasTEnabled = enabled;
+        }
+        catch(Exception e)
+        {
+            throw new SourceException("Couldn't set FCD Pro bias-T", e);
+        }
+    }
+
+    /**
+     * Turns off the bias-T, when enabled, before closing the device.
+     */
+    @Override
+    public void stop()
+    {
+        if(mBiasTEnabled)
+        {
+            try
+            {
+                setBiasT(false);
+            }
+            catch(Exception e)
+            {
+                mLog.warn("Error turning off FCD Pro bias-T before closing the device - " + e.getMessage());
+            }
+
+            mBiasTEnabled = false;
+        }
+
+        super.stop();
+    }
+
     /**
      * Gets the current LNA Gain value from the controller and stores it
      */

src/main/java/io/github/dsheirer/source/tuner/fcd/proV1/FCD1TunerEditor.java

@@ -19,6 +19,7 @@
 package io.github.dsheirer.source.tuner.fcd.proV1;
 
 import io.github.dsheirer.preference.UserPreferences;
+import io.github.dsheirer.source.SourceException;
 import io.github.dsheirer.source.tuner.fcd.FCDTuner;
 import io.github.dsheirer.source.tuner.fcd.proV1.FCD1TunerController.LNAEnhance;
 import io.github.dsheirer.source.tuner.fcd.proV1.FCD1TunerController.LNAGain;
@@ -32,6 +33,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.swing.JButton;
+import javax.swing.JCheckBox;
 import javax.swing.JComboBox;
 import javax.swing.JLabel;
 import javax.swing.JOptionPane;
@@ -52,6 +54,7 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
     private JComboBox<LNAGain> mLnaGainCombo;
     private JComboBox<LNAEnhance> mLnaEnhanceCombo;
     private JComboBox<MixerGain> mMixerGainCombo;
+    private JCheckBox mBiasTCheckBox;
     private CorrectionSpinner mCorrectionDCI;
     private CorrectionSpinner mCorrectionDCQ;
     private CorrectionSpinner mGainCorrectionSpinner;
@@ -121,6 +124,7 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
             getMixerGainCombo().setSelectedItem(getConfiguration().getMixerGain());
             getLnaEnhanceCombo().setSelectedItem(getConfiguration().getLNAEnhance());
             getLnaGainCombo().setSelectedItem(getConfiguration().getLNAGain());
+            getBiasTCheckBox().setSelected(getConfiguration().isBiasT());
             getDcCorrectionSpinnerI().setValue(getConfiguration().getInphaseDCCorrection());
             getDcCorrectionSpinnerQ().setValue(getConfiguration().getQuadratureDCCorrection());
             getPhaseCorrectionSpinner().setValue(getConfiguration().getGainCorrection());
@@ -130,6 +134,7 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
         getMixerGainCombo().setEnabled(hasTuner());
         getLnaEnhanceCombo().setEnabled(hasTuner());
         getLnaGainCombo().setEnabled(hasTuner());
+        getBiasTCheckBox().setEnabled(hasTuner());
         getDcCorrectionSpinnerI().setEnabled(hasTuner());
         getDcCorrectionSpinnerQ().setEnabled(hasTuner());
         getPhaseCorrectionSpinner().setEnabled(hasTuner());
@@ -164,6 +169,8 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
         add(getLnaEnhanceCombo(), "wrap");
         add(new JLabel("Mixer:"));
         add(getMixerGainCombo(), "wrap");
+        add(new JLabel(""));
+        add(getBiasTCheckBox(), "wrap");
 
         add(new JSeparator(), "span,growx,push");
         add(new JLabel("Correction"), "span,align center");
@@ -209,6 +216,37 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
         return mLnaGainCombo;
     }
 
+    /**
+     * Checkbox to enable/disable Bias-T power for active antennas
+     */
+    public JCheckBox getBiasTCheckBox()
+    {
+        if(mBiasTCheckBox == null)
+        {
+            mBiasTCheckBox = new JCheckBox("Bias-T");
+            mBiasTCheckBox.setEnabled(false);
+            mBiasTCheckBox.setToolTipText("Enable Bias-T power output for active antennas");
+            mBiasTCheckBox.addActionListener(event ->
+            {
+                if(hasTuner() && !isLoading())
+                {
+                    try
+                    {
+                        getController().setBiasT(mBiasTCheckBox.isSelected());
+                        save();
+                    }
+                    catch(SourceException e)
+                    {
+                        mLog.error("Couldn't set bias-T for FCD Pro", e);
+                        JOptionPane.showMessageDialog(FCD1TunerEditor.this, "Couldn't set Bias-T: " + e.getMessage());
+                    }
+                }
+            });
+        }
+
+        return mBiasTCheckBox;
+    }
+
     public JComboBox getLnaEnhanceCombo()
     {
         if(mLnaEnhanceCombo == null)
@@ -386,6 +424,7 @@ public class FCD1TunerEditor extends TunerEditor<FCDTuner,FCD1TunerConfiguration
             getConfiguration().setLNAEnhance((LNAEnhance) mLnaEnhanceCombo.getSelectedItem());
             getConfiguration().setLNAGain((LNAGain) mLnaGainCombo.getSelectedItem());
             getConfiguration().setMixerGain((MixerGain) mMixerGainCombo.getSelectedItem());
+            getConfiguration().setBiasT(getBiasTCheckBox().isSelected());
             double dci = ((SpinnerNumberModel)mCorrectionDCI.getModel()).getNumber().doubleValue();
             getConfiguration().setInphaseDCCorrection(dci);
             double dcq = ((SpinnerNumberModel)mCorrectionDCQ.getModel()).getNumber().doubleValue();

src/main/java/io/github/dsheirer/source/tuner/fcd/proplusV2/FCD2TunerConfiguration.java

@@ -27,6 +27,7 @@ public class FCD2TunerConfiguration extends TunerConfiguration
 {
     private boolean mGainLNA = true;
     private boolean mGainMixer = true;
+    private boolean mBiasT = false;
 
     /**
      * Default constructor for JAXB
@@ -69,4 +70,15 @@ public class FCD2TunerConfiguration extends TunerConfiguration
     {
         mGainMixer = gain;
     }
+
+    @JacksonXmlProperty(isAttribute = true, localName = "bias_t")
+    public boolean isBiasT()
+    {
+        return mBiasT;
+    }
+
+    public void setBiasT(boolean enabled)
+    {
+        mBiasT = enabled;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/fcd/proplusV2/FCD2TunerController.java

@@ -43,6 +43,7 @@ public class FCD2TunerController extends FCDTunerController
     public static final int MINIMUM_TUNABLE_FREQUENCY_HZ = 150000;
     public static final int MAXIMUM_TUNABLE_FREQUENCY_HZ = 2050000000;
     public static final int SAMPLE_RATE = 192000;
+    private boolean mBiasTEnabled = false;
 
     /**
      * Constructs an instance
@@ -98,6 +99,48 @@ public class FCD2TunerController extends FCDTunerController
         send(FCDCommand.APP_SET_MIXER_GAIN, enabled ? 1 : 0);
     }
 
+    /**
+     * Enables/disables the Bias-T (RF bias tee) power output for active antennas
+     *
+     * @param enabled true to enable Bias-T, false to disable
+     * @throws SourceException on error
+     */
+    public void setBiasT(boolean enabled) throws SourceException
+    {
+        try
+        {
+            send(FCDCommand.APP_SET_BIAS_TEE, enabled ? 1 : 0);
+            mBiasTEnabled = enabled;
+        }
+        catch(Exception e)
+        {
+            throw new SourceException("Couldn't set FCD Pro Plus bias-T", e);
+        }
+    }
+
+    /**
+     * Turns off the bias-T, when enabled, before closing the device.
+     */
+    @Override
+    public void stop()
+    {
+        if(mBiasTEnabled)
+        {
+            try
+            {
+                setBiasT(false);
+            }
+            catch(Exception e)
+            {
+                mLog.warn("Error turning off FCD Pro Plus bias-T before closing the device - " + e.getMessage());
+            }
+
+            mBiasTEnabled = false;
+        }
+
+        super.stop();
+    }
+
     @Override
     public void apply(TunerConfiguration config) throws SourceException
     {
@@ -108,6 +151,7 @@ public class FCD2TunerController extends FCDTunerController
         {
             setLNAGain(fcd2.getGainLNA());
             setMixerGain(fcd2.getGainMixer());
+            setBiasT(fcd2.isBiasT());
         }
     }
 

src/main/java/io/github/dsheirer/source/tuner/fcd/proplusV2/FCD2TunerEditor.java

@@ -32,6 +32,7 @@ import javax.swing.JButton;
 import javax.swing.JCheckBox;
 import javax.swing.JLabel;
 import javax.swing.JOptionPane;
+import javax.swing.JPanel;
 import javax.swing.JSeparator;
 import javax.swing.SpinnerNumberModel;
 
@@ -45,6 +46,7 @@ public class FCD2TunerEditor extends TunerEditor<FCDTuner, FCD2TunerConfiguratio
     private JButton mTunerInfoButton;
     private JCheckBox mLnaGainCheckBox;
     private JCheckBox mMixerGainCheckBox;
+    private JCheckBox mBiasTCheckBox;
 
     /**
      * Constructs an instance
@@ -106,11 +108,13 @@ public class FCD2TunerEditor extends TunerEditor<FCDTuner, FCD2TunerConfiguratio
         getTunerInfoButton().setEnabled(hasTuner());
         getLnaGainCheckBox().setEnabled(hasTuner());
         getMixerGainCheckBox().setEnabled(hasTuner());
+        getBiasTCheckBox().setEnabled(hasTuner());
 
         if(hasTuner() && hasConfiguration())
         {
             getLnaGainCheckBox().setSelected(getConfiguration().getGainLNA());
             getMixerGainCheckBox().setSelected(getConfiguration().getGainMixer());
+            getBiasTCheckBox().setSelected(getConfiguration().isBiasT());
         }
 
         setLoading(false);
@@ -135,8 +139,12 @@ public class FCD2TunerEditor extends TunerEditor<FCDTuner, FCD2TunerConfiguratio
         add(getFrequencyPanel(), "wrap");
 
         add(new JSeparator(), "span,growx,push");
-        add(getLnaGainCheckBox());
+        JPanel checkBoxPanel = new JPanel();
-        add(getMixerGainCheckBox());
+        checkBoxPanel.setLayout(new MigLayout("insets 0", "[left][left][left]", ""));
+        checkBoxPanel.add(getLnaGainCheckBox());
+        checkBoxPanel.add(getMixerGainCheckBox());
+        checkBoxPanel.add(getBiasTCheckBox());
+        add(checkBoxPanel, "span,align left");
     }
 
     public JButton getTunerInfoButton()
@@ -204,6 +212,37 @@ public class FCD2TunerEditor extends TunerEditor<FCDTuner, FCD2TunerConfiguratio
         return mMixerGainCheckBox;
     }
 
+    /**
+     * Checkbox to enable/disable Bias-T power for active antennas
+     */
+    public JCheckBox getBiasTCheckBox()
+    {
+        if(mBiasTCheckBox == null)
+        {
+            mBiasTCheckBox = new JCheckBox("Bias-T");
+            mBiasTCheckBox.setEnabled(false);
+            mBiasTCheckBox.setToolTipText("Enable Bias-T power output for active antennas");
+            mBiasTCheckBox.addActionListener(event ->
+            {
+                if(hasTuner() && !isLoading())
+                {
+                    try
+                    {
+                        getController().setBiasT(getBiasTCheckBox().isSelected());
+                        save();
+                    }
+                    catch(SourceException e)
+                    {
+                        mLog.error("Couldn't set bias-T for FCD2", e);
+                        JOptionPane.showMessageDialog(mBiasTCheckBox, "Couldn't set Bias-T: " + e.getMessage());
+                    }
+                }
+            });
+        }
+
+        return mBiasTCheckBox;
+    }
+
     @Override
     public void setTunerLockState(boolean locked)
     {
@@ -255,6 +294,7 @@ public class FCD2TunerEditor extends TunerEditor<FCDTuner, FCD2TunerConfiguratio
             getConfiguration().setAutoPPMCorrectionEnabled(getAutoPPMCheckBox().isSelected());
             getConfiguration().setGainLNA(getLnaGainCheckBox().isSelected());
             getConfiguration().setGainMixer(getMixerGainCheckBox().isSelected());
+            getConfiguration().setBiasT(getBiasTCheckBox().isSelected());
             saveConfiguration();
         }
     }