diff --git a/nanovna.h b/nanovna.h
index 713da9d..54614c3 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -18,7 +18,7 @@
  */
 #include "ch.h"
 
-//#ifdef TINYSA_F303
+#ifdef TINYSA_F303
 #ifdef TINYSA_F072
 #error "Remove comment for #ifdef TINYSA_F303"
 #endif
@@ -26,7 +26,7 @@
 #define TINYSA4
 #endif
 #define TINYSA4_PROTO
-//#endif
+#endif
 
 #ifdef TINYSA_F072
 #ifdef TINYSA_F303
@@ -1156,7 +1156,7 @@ void set_trace_refpos(float refpos);
 #define S_STATE(X) ((X)&1)
 enum { S_OFF=0, S_ON=1, S_AUTO_OFF=2, S_AUTO_ON=3 };
 
-enum { SD_NORMAL, SD_PRECISE, SD_FAST, SD_MANUAL };
+enum { SD_NORMAL, SD_PRECISE, SD_FAST, SD_NOISE_SOURCE, SD_MANUAL };
 
 enum {W_OFF, W_SMALL, W_BIG};
 
diff --git a/plot.c b/plot.c
index c7a6700..e482533 100644
--- a/plot.c
+++ b/plot.c
@@ -2077,8 +2077,13 @@ static void update_level_meter(void){
 //    ili9341_fill(OFFSETX+minimum_text_width, graph_bottom+1, area_width-minimum_text_width, CHART_BOTTOM - graph_bottom);
   ili9341_set_foreground(LCD_FG_COLOR);
   int x_max = area_width+OFFSETX;
-  int w = ili9341_drawstring_size(level_text,OFFSETX, graph_bottom+1,3, x_max);         // TODO Size 4 does not transfer to remote desktop??????
-  ili9341_fill(OFFSETX, graph_bottom+34, x_max - OFFSETX, 11);
+#ifdef TINYSA4
+#define BIG_SIZE 5
+#else
+#define BIG_SIZE 3
+#endif
+  int w = ili9341_drawstring_size(level_text,OFFSETX, graph_bottom+1,BIG_SIZE, x_max);         // TODO Size 4 does not transfer to remote desktop??????
+  ili9341_fill(OFFSETX, graph_bottom+BIG_SIZE*11+1, x_max - OFFSETX, CHART_BOTTOM - (graph_bottom+BIG_SIZE*11+1) + 1);
 
   if (w < x_max)
     ili9341_fill(w, graph_bottom+1, x_max - w, CHART_BOTTOM - graph_bottom+1);
diff --git a/sa_core.c b/sa_core.c
index 2404017..9444c14 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1246,9 +1246,9 @@ void set_harmonic(int h)
 void set_step_delay(int d)                  // override RSSI measurement delay or set to one of three auto modes
 {
 
-  if ((3 <= d && d < 10) || d > 30000)         // values 0 (normal scan), 1 (precise scan) and 2(fast scan) have special meaning and are auto calculated
+  if ((SD_MANUAL <= d && d < 10) || d > 30000)         // values 0 (normal scan), 1 (precise scan) and 2(fast scan) have special meaning and are auto calculated
     return;
-  if (d <3) {
+  if (d <SD_MANUAL) {
     setting.step_delay_mode = d;
     setting.step_delay = 0;
     setting.offset_delay = 0;
@@ -2279,7 +2279,7 @@ void update_rbw(void)           // calculate the actual_rbw and the vbwSteps (#
   if (setting.frequency_step > 0) {
     freq_t target_frequency_step_x10;
 
-    if (setting.step_delay_mode==SD_FAST) {
+    if (setting.step_delay_mode==SD_FAST || setting.step_delay_mode==SD_NOISE_SOURCE) {
       target_frequency_step_x10 = frequency_step_x10;
     } else if (setting.step_delay_mode==SD_PRECISE) {
       target_frequency_step_x10 = 4*frequency_step_x10;
@@ -2287,7 +2287,7 @@ void update_rbw(void)           // calculate the actual_rbw and the vbwSteps (#
       target_frequency_step_x10 = 2*frequency_step_x10;
     }
 
-    if (target_frequency_step_x10 > actual_rbw_x10) { // RBW too small
+    if (target_frequency_step_x10 > actual_rbw_x10 && !(setting.step_delay_mode==SD_NOISE_SOURCE)) { // RBW too small
       vbwSteps = (target_frequency_step_x10 + actual_rbw_x10 - 1) / actual_rbw_x10; //((int)(2 * (frequency_step_x10 + (actual_rbw_x10/8)) / actual_rbw_x10)); // calculate # steps in between each frequency step due to rbw being less than frequency step
       if (vbwSteps<1)
         vbwSteps = 1;
diff --git a/ui_sa.c b/ui_sa.c
index 5178ce2..81ce3d4 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -2649,6 +2649,7 @@ static const menuitem_t menu_sweep_speed[] =
 #else
  { MT_ADV_CALLBACK | MT_LOW,SD_FAST,   "FAST",            menu_scanning_speed_acb},
 #endif
+ { MT_ADV_CALLBACK,     SD_NOISE_SOURCE,      "NOISE\nSOURCE",   menu_scanning_speed_acb},
 #ifdef TINYSA4
  { MT_KEYPAD,           KM_FAST_SPEEDUP,"SPEEDUP\n\b%s",  "2..20, 0=disable"},
 #else
@@ -3782,16 +3783,16 @@ redraw_cal_status:
   }
 #endif
   // Sweep time: SD_NORMAL, SD_PRECISE, SD_FAST, SD_MANUAL
-  static const char fscan[]={0, 'P', 'F', 'M'};
+  static const char fscan[]={0, 'P', 'F', 'N', 'M'};
   if (dirty) {
     calculate_step_delay();
     setting.actual_sweep_time_us = calc_min_sweep_time_us();
   }
 #if 0                   // Activate for sweep time debugging
-  lcd_printf(x, y, "%cScan:\n%5.3Fs", fscan[setting.step_delay_mode&3], (float)setting.sweep_time_us/ONE_SECOND_TIME);
+  lcd_printf(x, y, "%cScan:\n%5.3Fs", fscan[setting.step_delay_mode&7], (float)setting.sweep_time_us/ONE_SECOND_TIME);
 #endif
-  ili9341_set_foreground((setting.step_delay_mode&3) != 0 ? LCD_BRIGHT_COLOR_GREEN : LCD_FG_COLOR);
-  lcd_printf(x, y, "%cScan:", fscan[setting.step_delay_mode&3]);
+  ili9341_set_foreground((setting.step_delay_mode&7) != 0 ? LCD_BRIGHT_COLOR_GREEN : LCD_FG_COLOR);
+  lcd_printf(x, y, "%cScan:", fscan[setting.step_delay_mode&7]);
   ili9341_set_foreground((setting.step_delay || setting.sweep_time_us ) ? LCD_BRIGHT_COLOR_GREEN : LCD_FG_COLOR);
   lcd_printf(x, y+YSTEP, "%5.3Fs",(float)setting.actual_sweep_time_us/ONE_SECOND_TIME);
   y = add_quick_menu(y+=YSTEP, (menuitem_t *)menu_sweep_speed);