diff --git a/platform/drivers/baseband/HR_C6000_UV3x0.cpp b/platform/drivers/baseband/HR_C6000_UV3x0.cpp
index d113a9ed..366d1ca1 100644
--- a/platform/drivers/baseband/HR_C6000_UV3x0.cpp
+++ b/platform/drivers/baseband/HR_C6000_UV3x0.cpp
@@ -167,7 +167,7 @@ void HR_Cx000< M >::dmrMode()
 template< class M >
 void HR_Cx000< M >::fmMode()
 {
-    writeReg(M::CONFIG, 0x10, 0xF3);    // FM mode, Tier II, TimeSlot, 3rd layer mode, aligned (?)
+    writeReg(M::CONFIG, 0x10, 0x80);    // FM mode, Tier II, TimeSlot, 3rd layer mode, aligned (?)
     writeReg(M::CONFIG, 0x01, 0xB0);    // Swap TX IQ, two point mode for TX, IF mode for RX
     writeReg(M::CONFIG, 0x81, 0x04);    // Interrupt mask
     writeReg(M::CONFIG, 0xE5, 0x1A);    // Undocumented register
@@ -203,24 +203,23 @@ void HR_Cx000< M >::startAnalogTx(const TxAudioSource source, const FmConfig cfg
     if(source == TxAudioSource::MIC)     audioCfg |= 0x40;
     if(source == TxAudioSource::LINE_IN) audioCfg |= 0x02;
 
-    writeReg(M::CONFIG, 0xE2, 0x00);    // Mic preamp disabled, anti-pop disabled
-//     writeReg(M::CONFIG, 0xE4, 0x23);    // Lineout gain, first and second stage mic gain
+    // writeReg(M::CONFIG, 0xE2, 0x00);    // Mic preamp disabled, anti-pop disabled
+    writeReg(M::CONFIG, 0xE0, audioCfg);
     writeReg(M::CONFIG, 0xC2, 0x00);    // Codec AGC gain
+    writeReg(M::CONFIG, 0xE5, 0x1A);    // Unknown (Default value = 0A)
+    writeReg(M::CONFIG, 0x25, 0x0E);    // Undocumented Register
+    writeReg(M::CONFIG, 0x26, 0xFE);    // Undocumented register Turns off FM receive
+    writeReg(M::CONFIG, 0x83, 0xFF);    // Clear all Interrupts
+    writeReg(M::CONFIG, 0x87, 0x00);    // Clear Int Masks
     writeReg(M::CONFIG, 0xA1, 0x80);    // FM_mod, all modes cleared
     writeReg(M::CONFIG, 0x83, 0xFF);    // Clear all interrupt flags
     writeReg(M::CONFIG, 0x87, 0x00);    // Disable all interrupt sources
-//     writeReg(M::CONFIG, 0x04, 0x24);
-//     writeReg(M::CONFIG, 0x35, 0x40);
-//     writeReg(M::CONFIG, 0x3F, 0x04);
     writeReg(M::CONFIG, 0x34, static_cast< uint8_t >(cfg));
-    writeReg(M::CONFIG, 0x3E, 0x08);    // FM Modulation frequency deviation coefficient at the receiving end
     writeReg(M::AUX,    0x50, 0x00);
     writeReg(M::AUX,    0x51, 0x00);
-    writeReg(M::CONFIG, 0x60, 0x80);    // Start analog transmission
-    writeReg(M::CONFIG, 0x10, 0xF3);    // FM mode, Tier II, TimeSlot, 3rd layer mode, aligned (?)
-
-    writeReg(M::CONFIG, 0xE0, audioCfg);
+    writeReg(M::CONFIG, 0x3E, 0x08);    // FM Modulation frequency deviation coefficient at the receiving end
     writeReg(M::CONFIG, 0x37, 0x8C);    // DAC gain
+    writeReg(M::CONFIG, 0x60, 0x80);    // Start analog transmission
 }
 
 template< class M >
diff --git a/platform/drivers/baseband/radio_UV3x0.cpp b/platform/drivers/baseband/radio_UV3x0.cpp
index b364bde2..96f98dbb 100644
--- a/platform/drivers/baseband/radio_UV3x0.cpp
+++ b/platform/drivers/baseband/radio_UV3x0.cpp
@@ -18,6 +18,7 @@
  *   along with this program; if not, see <http://www.gnu.org/licenses/>   *
  ***************************************************************************/
 
+#include <interfaces/delays.h>
 #include <interfaces/nvmem.h>
 #include <interfaces/radio.h>
 #include <interfaces/gpio.h>
@@ -234,9 +235,15 @@ void radio_enableTx()
             break;
     }
 
+    //
+    // FIXME: workaround to fix a small carrier-only gap which appears at the
+    // beginning of each transmission. This problem is particularly evident in
+    // M17 mode because it causes the truncation of the preamble sequence.
+    //
+    sleepFor(0, 50);
+
     at1846s.setFuncMode(AT1846S_FuncMode::TX);
 
-    gpio_setPin(PA_EN_1);
 
     if(currTxBand == BND_VHF)
     {
@@ -247,6 +254,7 @@ void radio_enableTx()
         gpio_setPin(PA_SEL_SW);
     }
 
+    gpio_setPin(PA_EN_1);
     gpio_setPin(PA_EN_2);
 
     if(config->txToneEn)