diff --git a/main.c b/main.c
index 7044573..eb264fe 100644
--- a/main.c
+++ b/main.c
@@ -88,7 +88,7 @@ uint16_t redraw_request = 0; // contains REDRAW_XXX flags
 // Version text, displayed in Config->Version menu, also send by info command
 const char *info_about[]={
   BOARD_NAME,
-  "2019-2020 Copyright @Erik Kaashoek",
+  "2019-2022 Copyright @Erik Kaashoek",
   "2016-2020 Copyright @edy555",
   "SW licensed under GPL. See: https://github.com/erikkaashoek/tinySA",
   "Version: " VERSION,
diff --git a/nanovna.h b/nanovna.h
index 654a6c4..72ca6ab 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
@@ -219,8 +219,7 @@ typedef uint32_t freq_t;
  #define CORRECTION_LOW_OUT_DIRECT 7
  #define CORRECTION_LOW_OUT_ADF    8
  #define CORRECTION_LOW_OUT_MIXER  9
- #define CORRECTION_HIGH           10
- #define CORRECTION_SIZE           11
+ #define CORRECTION_SIZE           10
 #endif
 typedef float measurement_t[TRACES_MAX][POINTS_COUNT];
 extern measurement_t measured;
diff --git a/sa_cmd.c b/sa_cmd.c
index a5454d4..f58b9d5 100644
--- a/sa_cmd.c
+++ b/sa_cmd.c
@@ -22,16 +22,26 @@ static int points = 101; // For 's' and 'm' commands
 
 VNA_SHELL_FUNCTION(cmd_mode)
 {
+#ifdef TINYSA3
   static const char cmd_low_high[] = "low|high";
+#endif
   static const char cmd_in_out[] = "input|output";
   if (argc != 2) {
   usage:
-    usage_printf("mode %s %s\r\n", cmd_low_high,cmd_in_out);
+#ifdef TINYSA4
+    shell_printf("usage: mode low %s\r\n", cmd_in_out);
+#else
+    shell_printf("usage: mode %s %s\r\n", cmd_low_high,cmd_in_out);
+#endif
     return;
   }
+#ifdef TINYSA3
   int lh = get_str_index(argv[0], cmd_low_high);
+#else
+  int lh = 0;
+#endif
   int io = get_str_index(argv[1], cmd_in_out);
-  if (lh<0 || io<0)
+  if (lh < 0 || io<0)
     goto usage;
   menu_move_top();
   switch(lh+io*2)
@@ -40,18 +50,22 @@ VNA_SHELL_FUNCTION(cmd_mode)
     set_mode(M_LOW);
     ui_mode_normal();
     break;
+#ifdef TINYSA3
   case 1:
     set_mode(M_HIGH);
     ui_mode_normal();
     break;
+#endif
   case 2:
     set_mode(M_GENLOW);
     menu_push_lowoutput();
     break;
+#ifdef TINYSA3
   case 3:
     set_mode(M_GENHIGH);
     menu_push_highoutput();
     break;
+#endif
   }
 }
 
@@ -358,8 +372,12 @@ VNA_SHELL_FUNCTION(cmd_ext_gain)
 
 VNA_SHELL_FUNCTION(cmd_levelchange)
 {
-  if (argc != 1  || argv[0][0] == '?') {
-    usage_printf("levelchange -70..+70\r\n");
+  if (argc != 1) {
+#ifdef TINYSA4
+    shell_printf("usage: levelchange -90..+90\r\n");
+#else
+    shell_printf("usage: levelchange -70..+70\r\n");
+#endif
     return;
   }
   float f = my_atof(argv[0]);
@@ -510,7 +528,7 @@ VNA_SHELL_FUNCTION(cmd_rbw)
   if (argc != 1 || argv[0][0] == '?') {
   usage:
 #ifdef TINYSA4
-	usage_printf("rbw 0.3..850|auto\r\n%.1FHz\r\n", actual_rbw_x10*100.0);
+	usage_printf("rbw 0.2..850|auto\r\n%.1FHz\r\n", actual_rbw_x10*100.0);
 #else
 	usage_printf("rbw 2..600|auto\r\n%.1FHz\r\n", actual_rbw_x10*100.0);
 #endif
@@ -538,7 +556,11 @@ VNA_SHELL_FUNCTION(cmd_if)
 {
   if (argc != 1 || argv[0][0] == '?') {
   usage:
-    usage_printf("if {433M..435M}\r\n%QHz\r\n", setting.frequency_IF);
+#ifdef TINYSA4
+  usage_printf("usage: if {975M..979M}\r\n%QHz\r\n", setting.frequency_IF);
+#else
+    usage_printf("usage: if {433M..435M}\r\n%QHz\r\n", setting.frequency_IF);
+#endif
     return;
   }
   freq_t a = (freq_t)my_atoi(argv[0]);
@@ -1120,7 +1142,7 @@ VNA_SHELL_FUNCTION(cmd_correction)
 {
   (void)argc;
 #ifdef TINYSA4
-  static const char cmd[] = "low|lna|ultra|ultra_lna|direct|direct_lna|out|out_direct|out_adf|out_ultra|high|off|on";
+  static const char cmd[] = "low|lna|ultra|ultra_lna|direct|direct_lna|out|out_direct|out_adf|out_ultra|off|on";
   static const char range[] = "0-19";
 #else
   static const char cmd[] = "low|high";
diff --git a/sa_core.c b/sa_core.c
index 2aaf053..7784fed 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -2156,10 +2156,12 @@ pureRSSI_t get_frequency_correction(freq_t f)      // Frequency dependent RSSI c
 {
   pureRSSI_t cv = 0;
   int c=CORRECTION_LOW;
+#ifdef TINYSA3
   if (setting.mode == M_GENHIGH) {
     c = CORRECTION_HIGH;
     return float_TO_PURE_RSSI(0.0);
   }
+#endif
 #ifdef TINYSA4
   if (setting.mode == M_LOW) {