diff --git a/app/app.c b/app/app.c
index 20081c0..dfa83dd 100644
--- a/app/app.c
+++ b/app/app.c
@@ -1201,6 +1201,9 @@ void APP_end_tx(void)
 		#endif
 	}
 
+	// re-enable 300Hz TX HPF
+	BK4819_write_reg(0x2B, BK4819_read_reg(0x2B) & ~(1u << 2));
+
 	RADIO_setup_registers(false);
 
 	if (g_monitor_enabled)
diff --git a/firmware.bin b/firmware.bin
index a6b9f17..7af385a 100644
Binary files a/firmware.bin and b/firmware.bin differ
diff --git a/firmware.packed.bin b/firmware.packed.bin
index 0512e83..a80a49f 100644
Binary files a/firmware.packed.bin and b/firmware.packed.bin differ
diff --git a/functions.c b/functions.c
index 3551fef..6752613 100644
--- a/functions.c
+++ b/functions.c
@@ -294,7 +294,13 @@ void FUNCTION_Select(function_type_t Function)
 
 			if (g_eeprom.config.setting.enable_scrambler)
 				BK4819_set_scrambler(g_current_vfo->channel.scrambler);
-			
+
+			// 1of11 .. TEST ONLY
+			if (g_current_vfo->p_tx->code_type == CODE_TYPE_NONE)
+				BK4819_write_reg(0x2B, BK4819_read_reg(0x2B) |  (1u << 2));   // disable the 300Hz TX HPF
+			else
+				BK4819_write_reg(0x2B, BK4819_read_reg(0x2B) & ~(1u << 2));   // enable the 300Hz TX HPF
+
 			break;
 	}