diff --git a/sa_core.c b/sa_core.c
index cedad6e..f75b119 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -2091,19 +2091,22 @@ sweep_again:                                // stay in sweep loop when output mo
 
 
   // -------------------------- auto attenuate ----------------------------------
-#define AUTO_TARGET_LEVEL   -30
+#define AUTO_TARGET_LEVEL   -25
+#define AUTO_TARGET_WINDOW  2
+
   if (!in_selftest && setting.mode == M_LOW && setting.auto_attenuation && max_index[0] > 0) {  // calculate and apply auto attenuate
     setting.atten_step = false;     // No step attenuate in low mode auto attenuate
     int changed = false;
-    float actual_max_level = actual_t[max_index[0]] - get_attenuation();
-    if (actual_max_level < AUTO_TARGET_LEVEL - 11 && setting.attenuate >= 10) {
-      setting.attenuate -= 10.0;
+    int actual_max_level = (int) (actual_t[max_index[0]] - get_attenuation());
+    if (actual_max_level < AUTO_TARGET_LEVEL && setting.attenuate > 0) {
+      setting.attenuate -= AUTO_TARGET_LEVEL - actual_max_level;
+      if (setting.attenuate < 0)
+        setting.attenuate= 0;
       changed = true;
-    } else if (actual_max_level < AUTO_TARGET_LEVEL - 6 && setting.attenuate >= 5) {
-      setting.attenuate -= 5.0;
-      changed = true;
-    } else if (actual_max_level > AUTO_TARGET_LEVEL + 2 && setting.attenuate <= 20) {
-      setting.attenuate += 10.0;
+    } else if (actual_max_level > AUTO_TARGET_LEVEL && setting.attenuate < 30) {
+      setting.attenuate += actual_max_level - AUTO_TARGET_LEVEL;
+      if (setting.attenuate > 30)
+        setting.attenuate = 30;
       changed = true;
     }
 
@@ -3277,13 +3280,7 @@ void self_test(int test)
     int i = 15;       // calibrate low mode power on 30 MHz;
     test_prepare(i);
     setting.step_delay = 8000;
-#ifdef __SI4432__
-#define RBW_COUNT 57
-#endif
-#ifdef __SI4463__
-#define RBW_COUNT 7
-#endif
-    for (int j= 0; j < RBW_COUNT; j++ ) {
+    for (int j= 0; j < SI4432_RBW_count; j++ ) {
       if (setting.test_argument != 0)
         j = setting.test_argument;
 // do_again:
diff --git a/si4432.c b/si4432.c
index 655eb9b..fa214e8 100644
--- a/si4432.c
+++ b/si4432.c
@@ -349,11 +349,10 @@ typedef struct {
   int8_t   RSSI_correction_x_10;  // Correction * 10
   uint16_t RBWx10;                // RBW * 10 in kHz
 }RBW_t; // sizeof(RBW_t) = 4 bytes
-
-static RBW_t RBW_choices[] = {
+RBW_t RBW_choices[] = {
 // BW register    corr  freq
-                              {IF_BW(0,5,1),0,26},
-                              {IF_BW(0,5,2),0,28},
+//                              {IF_BW(0,5,1),0,26},
+//                              {IF_BW(0,5,2),0,28},
                               {IF_BW(0,5,3),3,31},
                               {IF_BW(0,5,4),-3,32},
                               {IF_BW(0,5,5),6,37},
@@ -413,6 +412,8 @@ static RBW_t RBW_choices[] = {
 
 };
 
+const int SI4432_RBW_count = ((int)(sizeof(RBW_choices)/sizeof(RBW_t)));
+
 static pureRSSI_t SI4432_RSSI_correction = float_TO_PURE_RSSI(-120);
 
 uint16_t SI4432_force_RBW(int i)
@@ -425,7 +426,7 @@ uint16_t SI4432_force_RBW(int i)
 
 uint16_t SI4432_SET_RBW(uint16_t WISH)  {
   int i;
-  for (i=0; i < (int)(sizeof(RBW_choices)/sizeof(RBW_t)) - 1; i++)
+  for (i=0; i < SI4432_RBW_count - 1; i++)
     if (WISH <= RBW_choices[i].RBWx10) 
       break; 
   return SI4432_force_RBW(i);
diff --git a/si4432.h b/si4432.h
index 771a46e..42ded3a 100644
--- a/si4432.h
+++ b/si4432.h
@@ -136,6 +136,7 @@ void SI4432_Set_Frequency ( uint32_t Freq );
 
 uint16_t SI4432_force_RBW(int i);
 uint16_t SI4432_SET_RBW(uint16_t WISH);
+extern const int SI4432_RBW_count;
 void SI4432_SetReference(int freq);
 #ifdef __FAST_SWEEP__
 void SI4432_Fill(int s, int start);