diff --git a/codec2talkie/build.gradle b/codec2talkie/build.gradle
index 87e72d0..64ed126 100644
--- a/codec2talkie/build.gradle
+++ b/codec2talkie/build.gradle
@@ -11,8 +11,8 @@ android {
         applicationId "com.radio.codec2talkie"
         minSdkVersion 23
         targetSdkVersion 30
-        versionCode 169
-        versionName "1.69"
+        versionCode 170
+        versionName "1.70"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
diff --git a/codec2talkie/src/main/java/com/radio/codec2talkie/transport/TransportFactory.java b/codec2talkie/src/main/java/com/radio/codec2talkie/transport/TransportFactory.java
index 39e32e1..023759d 100644
--- a/codec2talkie/src/main/java/com/radio/codec2talkie/transport/TransportFactory.java
+++ b/codec2talkie/src/main/java/com/radio/codec2talkie/transport/TransportFactory.java
@@ -40,7 +40,7 @@ public static Transport create(TransportType transportType, Context context) thr
 
         switch (transportType) {
             case USB:
-                return new UsbSerial(UsbPortHandler.getPort(), UsbPortHandler.getName(), context);
+                return new UsbSerial(UsbPortHandler.getPort(), UsbPortHandler.getName());
             case BLUETOOTH:
                 return new Bluetooth(BluetoothSocketHandler.getSocket(), BluetoothSocketHandler.getName());
             case TCP_IP:
diff --git a/codec2talkie/src/main/java/com/radio/codec2talkie/transport/UsbSerial.java b/codec2talkie/src/main/java/com/radio/codec2talkie/transport/UsbSerial.java
index a9ce0a8..1772fa5 100644
--- a/codec2talkie/src/main/java/com/radio/codec2talkie/transport/UsbSerial.java
+++ b/codec2talkie/src/main/java/com/radio/codec2talkie/transport/UsbSerial.java
@@ -21,18 +21,9 @@ public class UsbSerial implements Transport {
     private final UsbSerialPort _usbPort;
     private final String _name;
 
-    private final boolean _isPrefixEnabled;
-    private final byte[] _bytePrefix;
-
-    protected SharedPreferences _sharedPreferences;
-
-    public UsbSerial(UsbSerialPort usbPort, String name, Context context) {
+    public UsbSerial(UsbSerialPort usbPort, String name) {
         _usbPort = usbPort;
         _name = name;
-        _sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
-        _isPrefixEnabled = _sharedPreferences.getBoolean(PreferenceKeys.PORTS_USB_IS_PREFIX_ENABLED, false);
-        String prefix = _sharedPreferences.getString(PreferenceKeys.PORTS_USB_PREFIX, "");
-        _bytePrefix = TextTools.hexStringToByteArray(prefix);
     }
 
     @Override
@@ -48,15 +39,7 @@ public int read(byte[] data) throws IOException {
     @Override
     public int write(byte[] data) throws IOException {
         try {
-            if (_isPrefixEnabled) {
-                byte[] pkt = ByteBuffer.allocate(_bytePrefix.length + data.length)
-                        .put(_bytePrefix)
-                        .put(data)
-                        .array();
-                _usbPort.write(pkt, TX_TIMEOUT);
-            } else {
-                _usbPort.write(data, TX_TIMEOUT);
-            }
+            _usbPort.write(data, TX_TIMEOUT);
             return data.length;
         } catch (SerialTimeoutException e) {
             e.printStackTrace();
diff --git a/codec2talkie/src/main/res/values/strings.xml b/codec2talkie/src/main/res/values/strings.xml
index 568d28a..d265fca 100644
--- a/codec2talkie/src/main/res/values/strings.xml
+++ b/codec2talkie/src/main/res/values/strings.xml
@@ -194,8 +194,6 @@
     <string name="usb_serial_summary">Set USB serial settings, such as speed, bits, parity, etc.</string>
     <string name="usb_is_prefix_enabled_title">Enable USB packet prefix</string>
     <string name="usb_is_prefix_enabled_summary">Prefix USB data with the HEX string for LoRA UART modems</string>
-    <string name="usb_prefix_title">USB packet prefix value as HEX string</string>
-    <string name="usb_prefix_summary">Prefix sent content with a hex string (so called transmission target in UART modems), e.g. C0FFEE</string>
 
     <string name="app_audio_output_speaker_title">Play audio through the speaker</string>
     <string name="app_audio_output_speaker_summary">Output incoming audio through the speaker</string>
diff --git a/codec2talkie/src/main/res/xml/preferences_usb.xml b/codec2talkie/src/main/res/xml/preferences_usb.xml
index 96fe4e8..9e742ad 100644
--- a/codec2talkie/src/main/res/xml/preferences_usb.xml
+++ b/codec2talkie/src/main/res/xml/preferences_usb.xml
@@ -55,20 +55,5 @@
             app:defaultValue="false">
         </CheckBoxPreference>
 
-        <CheckBoxPreference
-            app:key="ports_usb_is_prefix_enabled"
-            app:title="@string/usb_is_prefix_enabled_title"
-            app:summary="@string/usb_is_prefix_enabled_summary"
-            app:defaultValue="false">
-        </CheckBoxPreference>
     </PreferenceCategory>
-
-    <EditTextPreference
-        app:key="ports_usb_prefix"
-        app:title="@string/usb_prefix_title"
-        app:summary = "@string/usb_prefix_summary"
-        app:dependency="ports_usb_is_prefix_enabled"
-        app:defaultValue="C0FFEE">
-    </EditTextPreference>
-
 </PreferenceScreen>
\ No newline at end of file