diff --git a/nanovna.h b/nanovna.h
index fd6d19b..2b78a8f 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -1072,6 +1072,7 @@ extern const float unit_scale_value[];
 extern const char  unit_scale_text[];
 #ifdef TINYSA4
 extern int debug_frequencies;
+extern int linear_averaging;
 #endif
 #if 1   // Still sufficient flash
 // Flash save area - flash7  : org = 0x0801B000, len = 20k in *.ld file
diff --git a/plot.c b/plot.c
index b76a6c4..e4db0ad 100644
--- a/plot.c
+++ b/plot.c
@@ -310,7 +310,11 @@ marker_to_value(const int i)
   float v = value(ref_marker_levels[markers[i].index]);
   if (markers[i].mtype & M_AVER) {
     int old_unit = setting.unit;
-    if (markers[i].mtype & M_NOISE)
+    if (markers[i].mtype & M_NOISE
+#ifdef TINYSA4
+        && linear_averaging
+        #endif
+    )
       setting.unit = U_WATT;            // Noise averaging should always be done in Watts
     v = 0;
     for (int i=0; i<sweep_points; i++)
diff --git a/sa_core.c b/sa_core.c
index 3941e05..9660b22 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -72,6 +72,7 @@ uint32_t old_CFGR;
 uint32_t orig_CFGR;
 
 int debug_frequencies = false;
+int linear_averaging = true;
 
 static freq_t old_freq[5] = { 0, 0, 0, 0,0};
 static freq_t real_old_freq[5] = { 0, 0, 0, 0,0};
@@ -4069,12 +4070,15 @@ static volatile int dummy;
         case AV_16: actual_t[i] = (actual_t[i]*15.0 + RSSI) / 16.0; break;
         case AV_100:
 #ifdef TINYSA4
+          if (linear_averaging)
         {
           int old_unit = setting.unit;
           setting.unit = U_WATT;            // Power averaging should always be done in Watts
           actual_t[i] = to_dBm((value(actual_t[i])*(scan_after_dirty-1) + value(RSSI)) / scan_after_dirty );
           setting.unit = old_unit;
         }
+          else
+            actual_t[i] = (actual_t[i]*(scan_after_dirty-1) + RSSI)/ scan_after_dirty;
 #else
         actual_t[i] = (actual_t[i]*(scan_after_dirty-1) + RSSI)/ scan_after_dirty;
 #endif
@@ -5863,6 +5867,23 @@ abort:
       test_validate(TEST_LEVEL);                       // Validate test
       shell_printf("Temp = %4.1f, level = %6.2f, delta = %6.2f\n\r",Si446x_get_temp() , peakLevel, (first_level - peakLevel)*10.0 );
     }
+  } else if (test == 10) {
+//    reset_settings(M_LOW);
+    set_refer_output(-1);
+    if (setting.test_argument > 0)
+      set_R(setting.test_argument);
+    set_attenuation(0);
+    int test_case = TEST_POWER;
+    for (int i=1; i<30; i++) {
+      set_sweep_points(51);
+      set_sweep_frequency(ST_CENTER, 30000000 * i);
+      set_sweep_frequency(ST_SPAN, 3000);
+      test_acquire(test_case);                        // Acquire test
+      test_validate(test_case);
+      shell_printf("Freq = %8.3fMHz, level = %6.2f\n\r", ((float)peakFreq) / 1000000.0, peakLevel);
+    }
+    set_sweep_points(450);
+    reset_settings(M_LOW);
 #endif
   }
 
diff --git a/ui_sa.c b/ui_sa.c
index be6287f..6dacaa1 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -1157,6 +1157,22 @@ static UI_FUNCTION_ADV_CALLBACK(menu_debug_freq_acb)
   //  menu_move_back();
   ui_mode_normal();
 }
+
+
+static UI_FUNCTION_ADV_CALLBACK(menu_linear_averaging_acb)
+{
+  (void)data;
+  (void)item;
+  if (b){
+    b->icon = linear_averaging == 0 ? BUTTON_ICON_NOCHECK : BUTTON_ICON_CHECK;
+    return;
+  }
+  linear_averaging = ! linear_averaging;
+  //  menu_move_back();
+  ui_mode_normal();
+}
+
+
 #endif
 
 static UI_FUNCTION_CALLBACK(menu_clearconfig_cb)
@@ -2556,6 +2572,7 @@ static const menuitem_t menu_settings4[] =
 #ifdef __HARMONIC__
   { MT_SUBMENU,0,               "HARMONIC",         menu_harmonic},
 #endif
+  { MT_ADV_CALLBACK,     0,     "LINEAR\nAVERAGING",          menu_linear_averaging_acb},
 //  { MT_SUBMENU,  0,             S_RARROW" MORE",     menu_settings3},
   { MT_NONE,     0, NULL, menu_back} // next-> menu_back
 };