diff --git a/Makefile b/Makefile
index 0806d90..386464b 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ ENABLE_REVERSE_BAT_SYMBOL     := 1
 ENABLE_CODE_SCAN_TIMEOUT      := 0
 ENABLE_AM_FIX                 := 1
 ENABLE_AM_FIX_SHOW_DATA       := 1
-ENABLE_SQUELCH_LOWER          := 0
+ENABLE_SQUELCH_LOWER          := 1
 ENABLE_RSSI_BAR               := 1
 ENABLE_AUDIO_BAR              := 1
 #ENABLE_COPY_CHAN_TO_VFO       := 1
@@ -39,7 +39,8 @@ ENABLE_AUDIO_BAR              := 1
 
 TARGET = firmware
 
-ifeq ($(ENABLE_LTO),1)
+ifeq ($(ENABLE_LTO), 1)
+	# can't have LTO and OVERLAY enabled at same time
 	ENABLE_OVERLAY := 0
 endif
 
@@ -101,7 +102,9 @@ OBJS += app/scanner.o
 ifeq ($(ENABLE_UART),1)
 	OBJS += app/uart.o
 endif
-OBJS += am_fix.o
+ifeq ($(ENABLE_AM_FIX), 1)
+	OBJS += am_fix.o
+endif
 OBJS += audio.o
 OBJS += bitmaps.o
 OBJS += board.o
@@ -134,7 +137,7 @@ OBJS += ui/welcome.o
 OBJS += version.o
 OBJS += main.o
 
-ifeq ($(OS),Windows_NT)
+ifeq ($(OS), Windows_NT)
 	TOP := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
 else
 	TOP := $(shell pwd)
@@ -163,7 +166,7 @@ CFLAGS = -Os -Wall -Werror -mcpu=cortex-m0 -fno-builtin -fshort-enums -fno-delet
 #CFLAGS = -Os -Wall -Werror -mcpu=cortex-m0 -fno-builtin -fshort-enums -fno-delete-null-pointer-checks -std=gnu99 -MMD
 #CFLAGS = -Os -Wall -Werror -mcpu=cortex-m0 -fno-builtin -fshort-enums -fno-delete-null-pointer-checks -std=gnu11 -MMD
 
-ifeq ($(ENABLE_LTO),1)
+ifeq ($(ENABLE_LTO), 1)
 #	CFLAGS += -flto
 	CFLAGS += -flto=2
 endif
diff --git a/am_fix.c b/am_fix.c
index 54a4bce..61ddbea 100644
--- a/am_fix.c
+++ b/am_fix.c
@@ -30,12 +30,6 @@
 #include "functions.h"
 #include "misc.h"
 
-// original QS front end register settings
-const uint8_t orig_lna_short = 3;   //   0dB
-const uint8_t orig_lna       = 2;   // -14dB
-const uint8_t orig_mixer     = 3;   //   0dB
-const uint8_t orig_pga       = 6;   //  -3dB
-
 #ifdef ENABLE_AM_FIX
 
 	typedef struct
diff --git a/app/app.c b/app/app.c
index 2b2925d..90f1355 100644
--- a/app/app.c
+++ b/app/app.c
@@ -62,6 +62,12 @@
 #include "ui/status.h"
 #include "ui/ui.h"
 
+// original QS front end register settings
+const uint8_t orig_lna_short = 3;   //   0dB
+const uint8_t orig_lna       = 2;   // -14dB
+const uint8_t orig_mixer     = 3;   //   0dB
+const uint8_t orig_pga       = 6;   //  -3dB
+
 static void APP_ProcessKey(KEY_Code_t Key, bool bKeyPressed, bool bKeyHeld);
 
 static void updateRSSI(const int vfo)
@@ -538,10 +544,10 @@ void APP_StartListening(FUNCTION_Type_t Function, const bool reset_am_fix)
 	// ******************************************
 
 	// original setting
-	uint8_t lna_short = orig_lna_short;
-	uint8_t lna       = orig_lna;
-	uint8_t mixer     = orig_mixer;
-	uint8_t pga       = orig_pga;
+	uint16_t lna_short = orig_lna_short;
+	uint16_t lna       = orig_lna;
+	uint16_t mixer     = orig_mixer;
+	uint16_t pga       = orig_pga;
 
 	if (gRxVfo->AM_mode)
 	{	// AM
@@ -577,7 +583,7 @@ void APP_StartListening(FUNCTION_Type_t Function, const bool reset_am_fix)
 	}
 
 	// apply the front end gain settings
-	BK4819_WriteRegister(BK4819_REG_13, ((uint16_t)lna_short << 8) | ((uint16_t)lna << 5) | ((uint16_t)mixer << 3) | ((uint16_t)pga << 0));
+	BK4819_WriteRegister(BK4819_REG_13, (lna_short << 8) | (lna << 5) | (mixer << 3) | (pga << 0));
 
 	// ******************************************
 
@@ -1728,12 +1734,7 @@ void APP_TimeSlice500ms(void)
 
 	if (gSerialConfigCountDown_500ms > 0)
 	{
-		gReducedService = true;            // a serial config upload/download is in progress
-
-//		if (gCurrentFunction == FUNCTION_TRANSMIT)
-//		{	// stop transmitting
-//
-//		}
+//		gReducedService = true;            // a serial config upload/download is in progress
 	}
 	
 	// Skipped authentic device check
diff --git a/app/app.h b/app/app.h
index f71765d..8d029b0 100644
--- a/app/app.h
+++ b/app/app.h
@@ -23,6 +23,11 @@
 #include "frequencies.h"
 #include "radio.h"
 
+extern const uint8_t orig_lna_short;
+extern const uint8_t orig_lna;
+extern const uint8_t orig_mixer;
+extern const uint8_t orig_pga;
+
 void     APP_EndTransmission(void);
 void     CHANNEL_Next(bool bFlag, int8_t Direction);
 void     APP_StartListening(FUNCTION_Type_t Function, const bool reset_am_fix);
diff --git a/app/uart.c b/app/uart.c
index 21f7f1d..913b56f 100644
--- a/app/uart.c
+++ b/app/uart.c
@@ -230,8 +230,7 @@ static void CMD_0514(const uint8_t *pBuffer)
 		gFmRadioCountdown_500ms = fm_radio_countdown_500ms;
 	#endif
 
-	gSerialConfigCountDown_500ms = 6; // 3 sec
-	gSerialConfigCountDown_done  = false;
+	gSerialConfigCountDown_500ms = 12; // 6 sec
 	
 	// turn the LCD backlight off
 	GPIO_ClearBit(&GPIOB->DATA, GPIOB_PIN_BACKLIGHT);
@@ -248,8 +247,7 @@ static void CMD_051B(const uint8_t *pBuffer)
 	if (pCmd->Timestamp != Timestamp)
 		return;
 
-	gSerialConfigCountDown_500ms = 6; // 3 sec
-	gSerialConfigCountDown_done  = false;
+	gSerialConfigCountDown_500ms = 12; // 6 sec
 
 	#ifdef ENABLE_FMRADIO
 		gFmRadioCountdown_500ms = fm_radio_countdown_500ms;
@@ -280,9 +278,8 @@ static void CMD_051D(const uint8_t *pBuffer)
 	if (pCmd->Timestamp != Timestamp)
 		return;
 
-	gSerialConfigCountDown_500ms = 6; // 3 sec
-	gSerialConfigCountDown_done  = false;
-
+	gSerialConfigCountDown_500ms = 12; // 6 sec
+	
 	bReloadEeprom = false;
 
 	#ifdef ENABLE_FMRADIO
@@ -404,8 +401,7 @@ static void CMD_052F(const uint8_t *pBuffer)
 	if (gCurrentFunction == FUNCTION_POWER_SAVE)
 		FUNCTION_Select(FUNCTION_FOREGROUND);
 
-	gSerialConfigCountDown_500ms = 6; // 3 sec
-	gSerialConfigCountDown_done  = false;
+	gSerialConfigCountDown_500ms = 12; // 6 sec
 
 	Timestamp = pCmd->Timestamp;
 
diff --git a/firmware.bin b/firmware.bin
index 96c9974..087459c 100644
Binary files a/firmware.bin and b/firmware.bin differ
diff --git a/firmware.packed.bin b/firmware.packed.bin
index 3e97c4c..5b72d44 100644
Binary files a/firmware.packed.bin and b/firmware.packed.bin differ
diff --git a/misc.c b/misc.c
index ab3897b..2d8df9d 100644
--- a/misc.c
+++ b/misc.c
@@ -126,7 +126,6 @@ volatile bool     gDualWatchCountdownExpired = true;
 bool              gDualWatchActive           = false;
 
 volatile uint8_t  gSerialConfigCountDown_500ms;
-volatile bool     gSerialConfigCountDown_done;
 
 volatile bool     gNextTimeslice_500ms;
 
diff --git a/misc.h b/misc.h
index 5d8bd8a..38c2288 100644
--- a/misc.h
+++ b/misc.h
@@ -196,7 +196,6 @@ extern volatile bool         gDualWatchCountdownExpired;
 extern bool                  gDualWatchActive;
 
 extern volatile uint8_t      gSerialConfigCountDown_500ms;
-extern volatile bool         gSerialConfigCountDown_done;
 
 extern volatile bool         gNextTimeslice_500ms;
 
diff --git a/scheduler.c b/scheduler.c
index 2afecfa..21ae085 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -57,7 +57,7 @@ void SystickHandler(void)
 		gNextTimeslice_500ms = true;
 		
 		DECREMENT_AND_TRIGGER(gTxTimerCountdown_500ms, gTxTimeoutReached);
-		DECREMENT_AND_TRIGGER(gSerialConfigCountDown_500ms, gSerialConfigCountDown_done);
+		DECREMENT(gSerialConfigCountDown_500ms);
 	}
 
 	if ((gGlobalSysTickCounter & 3) == 0)
diff --git a/ui/menu.c b/ui/menu.c
index 618c4e3..4c5ecea 100644
--- a/ui/menu.c
+++ b/ui/menu.c
@@ -574,6 +574,7 @@ void UI_DisplayMenu(void)
 		#ifdef ENABLE_AM_FIX_TEST1
 			case MENU_AM_FIX_TEST1:
 				strcpy(String, gSubMenu_AM_fix_test1[gSubMenuSelection]);
+//				gSetting_AM_fix = gSubMenuSelection;
 				break;
 		#endif