diff --git a/main.c b/main.c
index d144b37..e367dae 100644
--- a/main.c
+++ b/main.c
@@ -1262,7 +1262,7 @@ const float  v5_2_correction_value[CORRECTION_SIZE][CORRECTION_POINTS]=
  /* out */   {   8.37,   5.53,   2.3,    -1.37,  -3.14,  -3.43,  -5.06,  -5.59,  -5.95,  -5.59,  -4.55,  -5.06,  -5.06,  -5.59,  -5.35,  -5.78,  -5.12,  -5.17,  -3.81,  -2.37},
  /* direct */    {   -3.9,   -2.73,  -2.55,  -2.5,   -1.04,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03,  -0.03},
  /* adf */   {   -3.25,  -2.51,  -1.77,  -1.34,  -0.16,  2.8,    5.37,   5.23,   3.76,   -0.93,  -1.98,  -4.71,  -5.41,  -7.41,  -8.63,  -8.53,  -8.28,  -7.66,  -7.56,  -5.78},
- /* ultra */ {   8.24,   4.14,   1.31,   -1.56,  -3.29,  -5.09,  -5.59,  -4.86,  -5.78,  -4.61,  -4.67,  -2.02,  -2.93,  -0.36,  2.78,   1.84,   4.97,   8.07,   11.98,  11.47},
+ /* ultra */ {   8.24,   4.14,   1.31,   -1.56,  -3.29,  -5.09,  -5.59,  -4.86,  -5.78,  -4.61,  -4.67,  -2.02,  -2.93,  -0.36,  2.78,   1.84,   4.97,   8.07,   10.8,   22.47},
 };
 
 const float v5_2_harmonic_lna_level_offset = 0; // should be in correction table now -7;        // Depends on where the transition to harmonic is done!!!!!! TODO find best frequency to transition to harmonic
@@ -2447,7 +2447,7 @@ static const VNAShellCommand commands[] =
 #ifdef ENABLE_COLOR_COMMAND
     {"color"       , cmd_color       , CMD_RUN_IN_LOAD},
 #endif
-    { "if", cmd_if,    CMD_WAIT_MUTEX | CMD_RUN_IN_LOAD },
+    { "if", cmd_if,    CMD_RUN_IN_LOAD },
 #ifdef TINYSA4
     { "if1", cmd_if1,    CMD_RUN_IN_LOAD },
     { "lna2", cmd_lna2,    CMD_RUN_IN_LOAD },
diff --git a/nanovna.h b/nanovna.h
index f050ba8..f2e02de 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -177,7 +177,8 @@ extern char *hw_text;
 #define DRIVE2_MAX_FREQ     2100000000ULL           // LO drive 2
 #define LOW_SHIFT_FREQ      2000000ULL              // shift IF to avoid zero Hz within IF
 
-#define USE_SHIFT2_RBW  4000        // use shift2_level_offset if actual_rbw_x10 is larger then this.
+#define USE_SHIFT2_RBW  8500        // shift2_level_offset rbw
+#define USE_SHIFT1_RBW  6000        // shift1_level_offset rbw
 #ifdef __NEW_SWITCHES__
 #define DIRECT_START config.direct_start
 #define DIRECT_STOP  config.direct_stop
diff --git a/sa_core.c b/sa_core.c
index c24b849..9da8b60 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -4901,7 +4901,7 @@ again:                                                              // Spur redu
         pureRSSI = Si446x_RSSI(break_on_operation);
         if (LO_shifting && (signal_path != PATH_DIRECT)) {
           if (f < 5000000)
-            pureRSSI += float_TO_PURE_RSSI(actual_rbw_x10>USE_SHIFT2_RBW ? config.shift2_level_offset : (lf < LOW_SHIFT_FREQ ? config.shift1_level_offset: 0.0));
+            pureRSSI -= float_TO_PURE_RSSI(actual_rbw_x10 == USE_SHIFT2_RBW ? config.shift2_level_offset : (actual_rbw_x10 == USE_SHIFT1_RBW ? config.shift1_level_offset : 0));
           else
             pureRSSI += float_TO_PURE_RSSI(config.shift_level_offset);
         }
@@ -6689,8 +6689,8 @@ float measure_jump(int i) {
     right += actual_t[j];
   }
   right /= h_p;
-  if (i <= 1)              // for 2MHz jump
-    return(right-left); // returns level jump low to high frequency.
+//  if (i <= 1)              // for 2MHz jump
+//    return(right-left); // returns level jump low to high frequency.
   return (left - right);
 }
 #endif
@@ -7916,8 +7916,10 @@ void calibrate(void)
 //        setting.spur_removal = S_OFF;
 //        set_reflevel(-95);
     } else if (i <= 1) {
-      if (i == 1)
-        set_RBW(8500);
+      if (i == 0)
+        set_RBW(USE_SHIFT1_RBW);
+      else
+        set_RBW(USE_SHIFT2_RBW);
       set_refer_output(5);          // 2MHz
       setting.spur_removal = S_OFF;
     } else {