diff --git a/main.c b/main.c
index 678d5b9..d458f83 100644
--- a/main.c
+++ b/main.c
@@ -2504,7 +2504,9 @@ static const VNAShellCommand commands[] =
    { "a", cmd_a,	CMD_WAIT_MUTEX },
    { "b", cmd_b,	CMD_WAIT_MUTEX },
    { "t", cmd_t,    CMD_WAIT_MUTEX },
+#ifdef TINYSA4
    { "k", cmd_k,    CMD_WAIT_MUTEX },
+#endif
    { "e", cmd_e,	CMD_WAIT_MUTEX },
    { "s", cmd_s,	CMD_WAIT_MUTEX },
    { "m", cmd_m,	CMD_WAIT_MUTEX },
diff --git a/nanovna.h b/nanovna.h
index 59bbf60..2307785 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -18,7 +18,7 @@
  */
 #include "ch.h"
 
-//#ifdef TINYSA_F303
+#ifdef TINYSA_F303
 #include "adc_F303.h"
 #ifdef TINYSA_F072
 #error "Remove comment for #ifdef TINYSA_F303"
@@ -27,7 +27,7 @@
 #define TINYSA4
 #endif
 #define TINYSA4_PROTO
-//#endif
+#endif
 
 #ifdef TINYSA_F072
 #ifdef TINYSA_F303
diff --git a/plot.c b/plot.c
index 314b2b0..810c6a5 100644
--- a/plot.c
+++ b/plot.c
@@ -303,6 +303,29 @@ marker_to_value(const int i)
   return(value(ref_marker_levels[markers[i].index]));
 }
 
+#ifdef TINYSA3
+float sa_sqrtf(const float x)
+{
+  union
+  {
+    int i;
+    float x;
+  } u;
+  u.x = x;
+  u.i = (1<<29) + (u.i >> 1) - (1<<22);
+
+  // Two Babylonian Steps (simplified from:)
+  // u.x = 0.5f * (u.x + x/u.x);
+  // u.x = 0.5f * (u.x + x/u.x);
+  u.x =       u.x + x/u.x;
+  u.x = 0.25f*u.x + x/u.x;
+
+  return u.x;
+}
+#else
+#define sa_sqrtf(x) sqrtf(x)
+#endif
+
 // Function for convert to different type of values from dBm
 // Replaced some equal functions and use recalculated constants:
 // powf(10,x) =  expf(x * logf(10))
@@ -1469,7 +1492,7 @@ static void cell_draw_marker_info(int x0, int y0)
             h += marker_to_value(1);
           h_i++;
         }
-        float thd = 100.0 * sqrtf(h/p);
+        float thd = 100.0 * sa_sqrtf(h/p);
         setting.unit = old_unit;
         ili9341_set_foreground(marker_color(markers[0].mtype));
 //        j = 1;
diff --git a/sa_core.c b/sa_core.c
index 4e50941..60f0ca8 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1073,6 +1073,8 @@ void set_offset_delay(int d)                  // override RSSI measurement delay
 
 void set_average(int v)
 {
+  if (setting.average == v)
+    dirty = true;
   setting.average = v;
   trace[TRACE_TEMP].enabled = ((v != 0)
 #ifdef __QUASI_PEAK__
diff --git a/si4468.c b/si4468.c
index 79568d9..be7b628 100644
--- a/si4468.c
+++ b/si4468.c
@@ -868,65 +868,65 @@ static uint8_t SI4463_wait_response(void* buff, uint8_t len, uint8_t use_timeout
   return 1;
 }
 
+#define SI_FAST_SPEED    SPI_BR_DIV2
+
 void SI4463_do_api(void* data, uint8_t len, void* out, uint8_t outLen)
 {
   set_SPI_mode(SPI_MODE_SI);
-  SPI_BR_SET(SI4432_SPI, SI4432_SPI_SPEED);
+  SPI_BR_SET(SI4432_SPI, SI_FAST_SPEED);
 
-  while (!SI4463_READ_CTS) { my_microsecond_delay(1); }         // Wait for CTS
+#define SHORT_DELAY my_microsecond_delay(1)
+//#define SHORT_DELAY
 
-  {
-    //   SPI_BR_SET(SI4432_SPI, SPI_BR_DIV8);
+  while (!SI4463_READ_CTS) {SHORT_DELAY; }         // Wait for CTS
 
-    __disable_irq();
-    SI_CS_LOW;
-    for(uint8_t i=0;i<len;i++) {
+  __disable_irq();
+  SI_CS_LOW;
+
+  for(uint8_t i=0;i<len;i++) {
 #if 1                                               // Inline transfer
-      while (SPI_TX_IS_NOT_EMPTY(SI4432_SPI));
-      SPI_WRITE_8BIT(SI4432_SPI, ((uint8_t*)data)[i]);
-      while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
-        SPI_READ_8BIT(SI4432_SPI);
+//    while (SPI_TX_IS_NOT_EMPTY(SI4432_SPI));
+    SPI_WRITE_8BIT(SI4432_SPI, ((uint8_t*)data)[i]);
+    while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
+      SPI_READ_8BIT(SI4432_SPI);
 #else
-      shiftOut(((uint8_t*)data)[i]); // (pgm_read_byte(&((uint8_t*)data)[i]));
+    shiftOut(((uint8_t*)data)[i]); // (pgm_read_byte(&((uint8_t*)data)[i]));
 #endif
-    }
-    //    SPI_BR_SET(SI4432_SPI, SPI_BR_DIV8);
-    SI_CS_HIGH;
-    __enable_irq();
-
-    while (!SI4463_READ_CTS) { my_microsecond_delay(1); }         // Wait for CTS
+  }
+  //    SPI_BR_SET(SI4432_SPI, SPI_BR_DIV8);
+  SI_CS_HIGH;
+  //    __enable_irq();
 
-    if(out != NULL) { // If we have an output buffer then read command response into it
+  while (!SI4463_READ_CTS) { SHORT_DELAY; }         // Wait for CTS
 
-      __disable_irq();
-//      again:
-      SI_CS_LOW;
-      shiftOut( SI446X_CMD_READ_CMD_BUFF );
-      //          uint8_t cts = (shiftIn() == 0xFF);
-      shiftIn();                        // Should always be 0xFF
-//      uint8_t cts = 0xFF;
-//      if (cts)
-      {
-        // Get response data
-        for(uint8_t i=0;i<outLen;i++) {
+  if(out != NULL) { // If we have an output buffer then read command response into it
+    SI_CS_LOW;
+    SPI_BR_SET(SI4432_SPI, SI4432_SPI_SPEED);
+#if 1
+    SPI_WRITE_8BIT(SI4432_SPI,SI446X_CMD_READ_CMD_BUFF);
+    while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
+      SPI_READ_8BIT(SI4432_SPI);
+    SPI_WRITE_8BIT(SI4432_SPI, 0xFF);
+    while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
+      SPI_READ_8BIT(SI4432_SPI);
+#else
+    shiftOut( SI446X_CMD_READ_CMD_BUFF );
+    shiftIn();                        // Should always be 0xFF
+#endif
+    // Get response data
+    for(uint8_t i=0;i<outLen;i++) {
 #if 1                                               // Inline transfer
-          SPI_WRITE_8BIT(SI4432_SPI, 0xFF);
-          while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
-            while (SPI_RX_IS_EMPTY(SI4432_SPI)); //wait rx data in buffer
-          ((uint8_t*)out)[i] = SPI_READ_8BIT(SI4432_SPI);
+     SPI_WRITE_8BIT(SI4432_SPI, 0xFF);
+      while (SPI_IS_BUSY(SI4432_SPI)) // drop rx and wait tx
+        while (SPI_RX_IS_EMPTY(SI4432_SPI)); //wait rx data in buffer
+      ((uint8_t*)out)[i] = SPI_READ_8BIT(SI4432_SPI);
 #else
-          ((uint8_t*)out)[i] = shiftIn();
+      ((uint8_t*)out)[i] = shiftIn();
 #endif
-        }
-      }
-//      else {
-//        SI_CS_HIGH;
-//        goto again;
-//      }
-      SI_CS_HIGH;
-      __enable_irq();
     }
+    SI_CS_HIGH;
   }
+  __enable_irq();
 }
 
 #ifdef notused
@@ -1210,9 +1210,12 @@ void Si446x_getInfo(si446x_info_t* info)
 
 float Si446x_get_temp(void)
 {
-    uint8_t data[6] = { SI446X_CMD_GET_ADC_READING, 0x10 };
-    SI4463_do_api(data, 2, data, 6);
-    float t = (data[4] << 8) + data[5];
+    uint8_t data[8] = { SI446X_CMD_GET_ADC_READING, 0x10, 0 };
+    SI4463_do_api(data, 3, data, 8);
+    int i = 4;
+    if (MODE_OUTPUT(setting.mode))
+      i = 6;
+    float t = (data[i] << 8) + data[i+1];
     t = (899.0 * t /4096.0) - 293.0;
     return t;
 }
diff --git a/ui_sa.c b/ui_sa.c
index 6aebb86..89e747a 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -570,7 +570,7 @@ static UI_FUNCTION_ADV_CALLBACK(menu_curve_acb)
   (void)item;
   int old_m;
   if (b){
-    plot_printf(uistat.text, sizeof uistat.text, "%.3QHz %+.1fdB",
+    plot_printf(uistat.text, sizeof uistat.text, "%8.3QHz %+4.1fdB",
                 config.correction_frequency[current_curve][data],
                 config.correction_value[current_curve][data]);
     b->param_1.text = uistat.text;
@@ -609,6 +609,7 @@ static UI_FUNCTION_ADV_CALLBACK(menu_curve_acb)
     common:
     set_sweep_frequency(ST_SPAN,   1000000);
     set_sweep_frequency(ST_CENTER, config.correction_frequency[current_curve][data]);
+    setting.step_delay_mode = SD_PRECISE;
     current_curve_index = data;
     menu_push_submenu(menu_curve_confirm);
     break;
@@ -1401,7 +1402,7 @@ static UI_FUNCTION_ADV_CALLBACK(menu_average_acb)
     return;
   }
   set_average(data);
-  menu_move_back(true);
+//  menu_move_back(true);
 }
 
 extern const menuitem_t menu_marker_modify[];
@@ -2395,7 +2396,7 @@ static const menuitem_t menu_actual_power[] =
 #ifdef TINYSA4
  { MT_CALLBACK,     0,                  "INPUT\nCURVE",  menu_input_curve_prepare_cb},
  { MT_CALLBACK,     0,                  "LNA\nCURVE",    menu_lna_curve_prepare_cb},
- { MT_SUBMENU | MT_LOW, 0,              "OUTPUT\nCURVE", menu_output_curve_prepare_cb},
+ { MT_CALLBACK,     0,                  "OUTPUT\nCURVE", menu_output_curve_prepare_cb},
 #endif
   { MT_CANCEL,   0,             S_LARROW" BACK", NULL },
   { MT_NONE,     0, NULL, NULL } // sentinel