diff --git a/main.c b/main.c
index 9347a0f..67fe4a0 100644
--- a/main.c
+++ b/main.c
@@ -2712,7 +2712,7 @@ int main(void)
   set_mode(M_LOW);
   set_sweep_frequency(ST_STOP, (uint32_t) 4000000);
   sweep(true);
-  set_sweep_frequency(ST_STOP, (uint32_t) 35000000);
+  set_sweep_frequency(ST_STOP, (uint32_t) 350000000);
 
   set_refer_output(-1);
 //  ui_mode_menu();       // Show menu when autostarting mode
diff --git a/sa_core.c b/sa_core.c
index 0235140..f898c3b 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -516,7 +516,7 @@ void set_harmonic(int h)
 void set_step_delay(int d)
 {
 
-  if ((2 <= d && d < 300) || d > 30000)
+  if ((3 <= d && d < 300) || d > 30000)
     return;
   setting.step_delay = d;
   dirty = true;
@@ -768,7 +768,7 @@ void apply_settings(void)
   SI4432_SetReference(setting.refer);
   update_rbw();
   if (setting.frequency_step == 0.0) {
-    if (setting.step_delay <= 1)
+    if (setting.step_delay <= 2)
       actualStepDelay = 0;
     else
       actualStepDelay = setting.step_delay;
@@ -824,6 +824,7 @@ int peakIndex;
 float temppeakLevel;
 int temppeakIndex;
 static unsigned long old_freq[4] = { 0, 0, 0, 0 };
+static unsigned long real_old_freq[4] = { 0, 0, 0, 0 };
 
 
 void setupSA(void)
@@ -831,6 +832,8 @@ void setupSA(void)
   SI4432_Init();
   old_freq[0] = 0;
   old_freq[1] = 0;
+  real_old_freq[0] = 0;
+  real_old_freq[1] = 0;
   SI4432_Sel = 0;
   SI4432_Receive();
 
@@ -839,6 +842,8 @@ void setupSA(void)
   PE4302_init();
   PE4302_Write_Byte(0);
 }
+extern int SI4432_frequency_changed;
+extern int SI4432_offset_changed;
 
 void set_freq(int V, unsigned long freq)
 {
@@ -846,16 +851,43 @@ void set_freq(int V, unsigned long freq)
     if (V <= 1) {
       SI4432_Sel = V;
       if (freq < 240000000 || freq > 960000000) {
-        old_freq[V] = freq + 1;
+        real_old_freq[V] = freq + 1;
         return;
       }
+#if 1
+      if (setting.step_delay == 2) {
+        int delta =  freq - real_old_freq[V];
+
+        if (real_old_freq[V] >= 480000000)    // 480MHz, high band
+          delta = delta >> 1;
+        if (delta > 0 && delta < 80000) { // use frequency deviation registers
+          if (1) {
+            if (real_old_freq[V] >= 480000000)
+              shell_printf("%d: Offs %q HW %d\r\n", SI4432_Sel, (uint32_t)(real_old_freq[V]+delta*2),  real_old_freq[V]);
+            else
+              shell_printf("%d: Offs %q HW %d\r\n", SI4432_Sel, (uint32_t)(real_old_freq[V]+delta*1),  real_old_freq[V]);
+          }
+
+          delta = delta * 4 / 625; // = 156.25;
+          SI4432_Write_Byte(0x73, (uint8_t)(delta & 0xff));
+          uint8_t reg = delta >> 8;
+          SI4432_Write_Byte(0x74, (uint8_t)((delta >> 8) & 0x03));
+          SI4432_offset_changed = true;
+          old_freq[V] = freq;
+          return;
+        }
+#endif
+      }
       SI4432_Set_Frequency(freq);
+      SI4432_Write_Byte(0x73, 0);
+      SI4432_Write_Byte(0x74, 0);
 #ifdef __ULTRA_SA__
     } else {
       ADF4351_set_frequency(V-2,freq,3);
 #endif
     }
     old_freq[V] = freq;
+    real_old_freq[V] = freq;
   }
 }
 
@@ -886,7 +918,9 @@ void set_switches(int m)
   SI4432_Init();
   old_freq[0] = 0;
   old_freq[1] = 0;
-switch(m) {
+  real_old_freq[0] = 0;
+  real_old_freq[1] = 0;
+  switch(m) {
 case M_LOW:     // Mixed into 0
 #ifdef __ULTRA__
 case M_ULTRA:
@@ -2724,8 +2758,8 @@ void self_test(int test)
     setting.auto_IF = false;
     setting.frequency_IF=433900000;
     ui_mode_normal();
-    int i = 13;       // calibrate low mode power on 30 MHz;
-//    int i = 15;       // calibrate low mode power on 30 MHz;
+//    int i = 13;       // calibrate low mode power on 30 MHz;
+    int i = 15;       // calibrate low mode power on 30 MHz;
     test_prepare(i);
     setting.step_delay = 8000;
     for (int j= 0; j < 57; j++ ) {
diff --git a/si4432.c b/si4432.c
index 8beccae..7e17dd6 100644
--- a/si4432.c
+++ b/si4432.c
@@ -310,6 +310,8 @@ void set_10mhz(uint32_t f)
 }
 
 int SI4432_frequency_changed = false;
+int SI4432_offset_changed = false;
+
 #if 0
 static int old_freq_band[2] = {-1,-1};
 static int written[2]= {0,0};
@@ -319,6 +321,7 @@ void SI4432_Set_Frequency ( uint32_t Freq ) {
 //  int mode = SI4432_Read_Byte(0x02) & 0x03;
 //  SI4432_Write_Byte(0x07, 0x02);    // Switch to tune mode
   uint8_t hbsel;
+  if (1) shell_printf("%d: Freq %q\r\n", SI4432_Sel, Freq);
   if (Freq >= 480000000U) {
     hbsel = 1<<5;
     Freq>>=1;
@@ -425,6 +428,9 @@ float SI4432_RSSI(uint32_t i, int s)
       stepdelay = 280;
     }
     SI4432_frequency_changed = false;
+  } else if (SI4432_offset_changed) {
+    stepdelay = 280 + stepdelay/4;
+    SI4432_offset_changed = false;
   }
   if (stepdelay)
     my_microsecond_delay(stepdelay);
@@ -557,13 +563,13 @@ void SI4432_Init()
   SI4432_Sel = 0;
 //  SI4432_Receive();// Enable receiver chain
 //  SI4432_Write_Byte(0x09, V0_XTAL_CAPACITANCE);// Tune the crystal
-  SI4432_Set_Frequency(433800000);
+//  SI4432_Set_Frequency(433800000);
   SI4432_Write_Byte(0x0D, 0x1F) ; // Set GPIO2 output to ground
 
 
   SI4432_Sel = 1;
 //  SI4432_Write_Byte(0x09, V1_XTAL_CAPACITANCE);// Tune the crystal
-  SI4432_Set_Frequency(443800000);
+//  SI4432_Set_Frequency(443800000);
   SI4432_Write_Byte(0x0D, 0x1F) ; // Set GPIO2 output to ground
 
   //  SI4432_Write_Byte(0x6D, 0x1C);//Set low power
diff --git a/ui_sa.c b/ui_sa.c
index c4d23e3..6f3e7ff 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -1387,8 +1387,9 @@ static const menuitem_t menu_harmonic[] =
 
 static const menuitem_t menu_scanning_speed[] =
 {
- { MT_CALLBACK, 0,             "FAST",      menu_scanning_speed_cb},
- { MT_CALLBACK, 1,             "PRECISE",   menu_scanning_speed_cb},
+ { MT_CALLBACK, 0,             "FAST",              menu_scanning_speed_cb},
+ { MT_CALLBACK, 1,             "PRECISE",           menu_scanning_speed_cb},
+ { MT_CALLBACK, 2,             "\2EXTRA\0FAST",     menu_scanning_speed_cb},
  { MT_KEYPAD, KM_SAMPLETIME,   "\2SAMPLE\0DELAY",   "300..30000"},
  { MT_CANCEL,   0,             "\032 BACK", NULL },
  { MT_NONE,     0, NULL, NULL } // sentinel