diff --git a/NANOVNA_STM32_F072/board.h b/NANOVNA_STM32_F072/board.h
index 6ec8e5e..2e33d06 100644
--- a/NANOVNA_STM32_F072/board.h
+++ b/NANOVNA_STM32_F072/board.h
@@ -247,7 +247,7 @@
                                      PIN_MODE_OUTPUT(GPIO_RF_PWR) |          \
                                      PIN_MODE_OUTPUT(GPIO_SPI2_CLK) |          \
                                      PIN_MODE_OUTPUT(11) |          \
-                                     PIN_MODE_OUTPUT(12) | \
+                                     PIN_MODE_INPUT(12) | \
                                      PIN_MODE_OUTPUT(13) | \
                                      PIN_MODE_INPUT(GPIO_SPI2_SDO) | \
                                      PIN_MODE_OUTPUT(GPIO_SPI2_SDI))
diff --git a/main.c b/main.c
index b73e16c..a54d2e0 100644
--- a/main.c
+++ b/main.c
@@ -123,13 +123,13 @@ const char *info_about[]={
 };
 
 bool dirty = true;
-
 bool completed = false;
 
 #ifdef TINYSA4
 static THD_WORKING_AREA(waThread1, 1124);
 #else
 static THD_WORKING_AREA(waThread1, 768);
+bool has_esd = false;
 #endif
 static THD_FUNCTION(Thread1, arg)
 {
@@ -1022,7 +1022,7 @@ config_t config = {
   .cor_am = 0,
   .cor_wfm = 0,
   .cor_nfm = 0,
-  .ultra = false,
+  .ultra = true,
   .high_out_adf4350 = true,
   .ext_zero_level = 174,
 #endif
@@ -2278,6 +2278,10 @@ VNA_SHELL_FUNCTION(cmd_info)
   int i = 0;
   while (info_about[i])
     shell_printf("%s\r\n", info_about[i++]);
+#ifdef TINYSA3
+  if (has_esd)
+    shell_printf("ESD protected\r\n");
+#endif
 }
 #endif
 
@@ -2851,6 +2855,11 @@ int main(void)
   si5351_init();
 #endif
 
+#ifdef TINYSA3
+  has_esd = ((palReadPort(GPIOB) & (1<<12)) ? false : true );
+#endif
+
+
 #ifdef __SI4432__
  /*
   * Powercycle the RF part to reset SI4432
diff --git a/nanovna.h b/nanovna.h
index 8b15090..f08d2c6 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -84,7 +84,7 @@
 #define HIGH_MAX_FREQ_MHZ   960
 #endif
 #ifdef TINYSA4
-#define DEFAULT_IF  ((freq_t)977100000)
+#define DEFAULT_IF  ((freq_t)977400000)
 #define DEFAULT_SPUR_OFFSET ((freq_t)1500000)
 #define DEFAULT_MAX_FREQ    ((freq_t)800000000)
 #define HIGH_MIN_FREQ_MHZ   136// 825
@@ -120,6 +120,7 @@
 #ifdef TINYSA3
 typedef uint32_t freq_t;
  typedef int32_t long_t;
+ extern bool has_esd;
 #endif
 #ifdef TINYSA4
  typedef uint64_t freq_t;
diff --git a/plot.c b/plot.c
index 1755880..3338597 100644
--- a/plot.c
+++ b/plot.c
@@ -1301,7 +1301,7 @@ static void cell_draw_marker_info(int x0, int y0)
 #ifdef __CHANNEL_POWER__
   if (setting.measurement==M_CP) {
     for (int c=0; c<3;c++) {
-      plot_printf(buf, sizeof buf, "%4.1fdB", channel_power[c]);
+      plot_printf(buf, sizeof buf, "%4.1fdBm", channel_power[c]);
       int xpos = 10 + (c)*(WIDTH/3) + CELLOFFSETX - x0;
       int ypos = 1 - y0;
       ili9341_set_foreground(LCD_FG_COLOR);
diff --git a/sa_cmd.c b/sa_cmd.c
index b08b05d..ee69652 100644
--- a/sa_cmd.c
+++ b/sa_cmd.c
@@ -835,7 +835,7 @@ VNA_SHELL_FUNCTION(cmd_correction)
   if (argc == 0) {
     shell_printf("index frequency value\r\n");
     for (int i=0; i<CORRECTION_POINTS; i++) {
-      shell_printf("%d %D%.1f\r\n", i, setting.correction_frequency[i], setting.correction_value[i]);
+      shell_printf("%d %D %.1f\r\n", i, setting.correction_frequency[i], setting.correction_value[i]);
     }
     return;
   }
diff --git a/sa_core.c b/sa_core.c
index 06e097f..b1a7325 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -2240,7 +2240,7 @@ static void calculate_static_correction(void)                   // Calculate the
 #ifdef TINYSA4
           - (S_STATE(setting.agc)? 0 : 33)
           - (S_STATE(setting.lna)? 0 : 0)
-          + (setting.extra_lna ? -23.0 : 0)                         // TODO <------------------------- set correct value
+          + (setting.extra_lna ? -25.5 : 0)                         // TODO <------------------------- set correct value
 #endif		  
           - setting.external_gain);
 }
@@ -3946,11 +3946,11 @@ enum {
 
 #define W2P(w) (sweep_points * w / 100)     // convert width in % to actual sweep points
 
-//#ifdef TINYSA4
-//#define CAL_LEVEL   -30
-//#else
-#define CAL_LEVEL   -25
-//#endif
+#ifdef TINYSA4
+#define CAL_LEVEL   -29.5
+#else
+#define CAL_LEVEL   (has_esd ? -26.2 : -25)
+#endif
 
 // TODO made more compact this structure (need use aligned data)
 typedef struct test_case {
diff --git a/ui.c b/ui.c
index a2e5eee..c2f1e8b 100644
--- a/ui.c
+++ b/ui.c
@@ -504,6 +504,10 @@ show_version(void)
     do {shift>>=1; y+=5;} while (shift&1);
     ili9341_drawstring(info_about[i++], x, y+=5);
   }
+#ifdef TINYSA3
+  if (has_esd)
+    ili9341_drawstring("ESD protected", x, y+=5);
+#endif
 #ifdef TINYSA4
 extern const char *states[];
   #define ENABLE_THREADS_COMMAND