diff --git a/nanovna.h b/nanovna.h
index e656098..654a8db 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -401,6 +401,7 @@ void set_measurement(int);
 // extern int settingSpeed;
 //extern int setting.step_delay;
 void sweep_remote(void);
+void calculate_step_delay(void);
 extern int generic_option_cmd( const char *cmd, const char *cmd_list, int argc, char *argv);
 
 #ifdef TINYSA4
@@ -1184,7 +1185,7 @@ typedef struct properties {
 
 //sizeof(properties_t) == 0x1200
 
-#define CONFIG_MAGIC 0x434f4e4e /* 'CONF' */
+#define CONFIG_MAGIC 0x434f4e4f /* 'CONF' */
 
 extern int16_t lastsaveid;
 //extern properties_t *active_props;
diff --git a/sa_core.c b/sa_core.c
index 4167ebc..d76a906 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1447,7 +1447,7 @@ static const struct {
 };
 #endif
 
-static void calculate_step_delay(void)
+void calculate_step_delay(void)
 {
   if (setting.step_delay_mode == SD_MANUAL || setting.step_delay != 0) {        // The latter part required for selftest 3
     SI4432_step_delay = setting.step_delay;
@@ -3111,7 +3111,11 @@ again:                                                              // Spur redu
 #endif
             else
             {
+#ifdef TINYSA4
+              local_IF = local_IF - DEFAULT_SPUR_OFFSET/4;                  // No spure removal and no spur, center in IF but avoid mirror
+#else
               local_IF = local_IF; // + DEFAULT_SPUR_OFFSET/2;                  // No spure removal and no spur, center in IF
+#endif
             }
           }
         }
@@ -3174,7 +3178,7 @@ again:                                                              // Spur redu
             if (tf + actual_rbw_x10*100 >= lf  && tf < lf + actual_rbw_x10*100) {   // 30MHz
               ADF4351_R_counter(6);
             } else {
-              if (setting.frequency_step < 100000) {
+              if (actual_rbw_x10 < 1000) {
                 freq_t tf = ((lf + actual_rbw_x10*1000) / TXCO_DIV3) * TXCO_DIV3;
                 if (tf + actual_rbw_x10*100 >= lf  && tf < lf + actual_rbw_x10*100) // 10MHz
                   ADF4351_R_counter(4);
diff --git a/ui_sa.c b/ui_sa.c
index 5b485e7..0a15f56 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -3302,7 +3302,7 @@ redraw_cal_status:
   else
     color = LCD_FG_COLOR;
   ili9341_set_foreground(color);
-
+  if (dirty) update_rbw();
   ili9341_drawstring("RBW:", x, y);
   y += YSTEP;
   plot_printf(buf, BLEN, "%.1FHz", actual_rbw_x10*100.0);
@@ -3341,7 +3341,10 @@ redraw_cal_status:
     strcpy(&buf[0],"Scan:");
   ili9341_drawstring(buf, x, y);
 
-  if (dirty) setting.actual_sweep_time_us = calc_min_sweep_time_us();
+  if (dirty) {
+    calculate_step_delay();
+    setting.actual_sweep_time_us = calc_min_sweep_time_us();
+  }
 
 #if 0                   // Activate for sweep time debugging
   y += YSTEP;