diff --git a/flash.c b/flash.c
index bb90a12..598230d 100644
--- a/flash.c
+++ b/flash.c
@@ -71,8 +71,9 @@ checksum(const void *start, size_t len)
   uint32_t *tail = (uint32_t*)(start + len);
   uint32_t value = 0;
   while (p < tail) {
-    value = __ROR(value, 31) + *p++;
-    // if (SDU1.config->usbp->state == USB_ACTIVE) shell_printf("%x\r\n", value);
+    value = __ROR(value, 31) + *p;
+//    if (SDU1.config->usbp->state == USB_ACTIVE) shell_printf("%x, %x\r\n", *p, value);
+    p++;
   }
   return value;
 }
@@ -109,6 +110,7 @@ config_recall(void)
 
   if (src->magic != CONFIG_MAGIC)
     return -1;
+//  if (SDU1.config->usbp->state == USB_ACTIVE) shell_printf("Checksum %x\r\n", src->checksum);
   if (checksum(src, sizeof config - sizeof config.checksum) != src->checksum)
     return -1;
 
@@ -132,8 +134,9 @@ caldata_save(uint16_t id)
   dst = (uint16_t*)(SAVE_PROP_CONFIG_ADDR + id * SAVE_PROP_CONFIG_SIZE);
 
   setting.magic = CONFIG_MAGIC;
+  setting.checksum = 0x12345678;
   setting.checksum = checksum(
-      &setting, sizeof setting - sizeof setting.checksum);
+      &setting, (sizeof (setting)) - sizeof setting.checksum);
 
   flash_unlock();
 
@@ -179,7 +182,8 @@ caldata_recall(uint16_t id)
 
   if (src->magic != CONFIG_MAGIC)
     return -1;
-  if (checksum(src, sizeof setting - sizeof src->checksum) != src->checksum)
+//  if (SDU1.config->usbp->state == USB_ACTIVE) shell_printf("Checksum %x\r\n", src->checksum);
+  if (checksum(src, (sizeof (setting)) - sizeof src->checksum) != src->checksum)
     return -1;
 
   /* active configuration points to save data on flash memory */
diff --git a/nanovna.h b/nanovna.h
index a4c2f82..5caee68 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -858,6 +858,7 @@ typedef struct setting
   uint8_t agc;
   uint8_t lna;
   uint8_t auto_reflevel;
+  uint8_t dummy2;
   int modulation;
   int show_stored;
   int atten_step;
@@ -918,8 +919,8 @@ typedef struct setting
   int ultra;
   int R;
 #endif
-  uint32_t dummy;
-  uint32_t checksum;            // must be last
+  uint16_t dummy;
+  uint32_t checksum;            // must be last and at 4 byte boundary
 }setting_t;
 
 extern setting_t setting;
diff --git a/sa_core.c b/sa_core.c
index f6ed6ff..55e9e03 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -103,7 +103,7 @@ const int8_t drive_dBm [16] = {-38, -32, -30, -27, -24, -19, -15, -12, -5, -2, 0
 #define MAX_DRIVE   (setting.mode == M_GENHIGH ? 15 : 11)
 #define MIN_DRIVE   8
 #define SL_GENHIGH_LEVEL_MIN    -38
-#define SL_GENHIGH_LEVEL_RANGE    51
+#define SL_GENHIGH_LEVEL_RANGE    54
 #define SL_GENLOW_LEVEL_MIN    -76
 #define SL_GENLOW_LEVEL_RANGE   70
 #endif
@@ -670,8 +670,12 @@ void set_level(float v)     // Set the output level in dB  in high/low output
 //      d = 7;
     set_lo_drive(d);
   } else {
+    if (v < SL_GENLOW_LEVEL_MIN)
+      v = SL_GENLOW_LEVEL_MIN;
+    if (v > SL_GENLOW_LEVEL_MIN + SL_GENLOW_LEVEL_RANGE)
+      v = SL_GENLOW_LEVEL_MIN + SL_GENLOW_LEVEL_RANGE;
     setting.level = v;
-    set_attenuation(setting.level - config.low_level_output_offset);
+//    set_attenuation(setting.level - config.low_level_output_offset);
   }
   dirty = true;
 }
@@ -681,7 +685,7 @@ float get_level(void)
   if (setting.mode == M_GENHIGH) {
     return drive_dBm[setting.lo_drive] + config.high_level_output_offset;
   } else {
-    setting.level = get_attenuation() + config.low_level_output_offset;
+//    setting.level = get_attenuation() + config.low_level_output_offset;
     return setting.level;
   }
 }
@@ -701,8 +705,9 @@ float get_attenuation(void)
   return(actual_attenuation);
 }
 
-void set_attenuation(float a)       // Is used both in low output mode and high/low input mode
+void set_attenuation(float a)       // Is used both only in  high/low input mode
 {
+#if 0
   if (setting.mode == M_GENLOW) {
     a = a - level_max();               // Move to zero for max power
     if (a > 0)
@@ -719,7 +724,9 @@ void set_attenuation(float a)       // Is used both in low output mode and high/
     }
     a -= BELOW_MAX_DRIVE(setting.rx_drive);
     a = -a;
-  } else {
+  } else
+#endif
+  {
     if (setting.mode == M_LOW && a > 31.5) {
       setting.atten_step = 1;
       a = a - RECEIVE_SWITCH_ATTENUATION;
diff --git a/ui_sa.c b/ui_sa.c
index 566b3c4..da9dc02 100644
--- a/ui_sa.c
+++ b/ui_sa.c
@@ -404,7 +404,7 @@ static const keypads_t keypads_time[] = {
 enum {
   KM_START, KM_STOP, KM_CENTER, KM_SPAN, KM_CW, // These must be first to share common help text
   KM_REFLEVEL, KM_SCALE, KM_ATTENUATION,
-  KM_ACTUALPOWER, KM_IF, KM_SAMPLETIME, KM_DRIVE, KM_LOWOUTLEVEL, KM_DECAY, KM_NOISE,
+  KM_ACTUALPOWER, KM_IF, KM_SAMPLETIME, KM_LOWOUTLEVEL, KM_DECAY, KM_NOISE,
 #ifdef TINYSA4
   KM_30MHZ, 
 #else
@@ -439,7 +439,6 @@ static const struct {
   {keypads_plusmin_unit, "ACTUAL\nPOWER"}, // actual power
   {keypads_freq        , "IF"}, // IF
   {keypads_positive    , "SAMPLE\nDELAY"}, // sample delay
-  {keypads_positive    , "DRIVE"}, // KM_DRIVE
   {keypads_plusmin     , "LEVEL"},    // KM_LOWOUTLEVEL
   {keypads_positive    , "DECAY"},    // KM_DECAY
   {keypads_positive    , "NOISE\nLEVEL"},    // KM_NOISE
@@ -2256,10 +2255,6 @@ static void fetch_numeric_target(void)
     uistat.value = setting.repeat;
     plot_printf(uistat.text, sizeof uistat.text, "%2d", ((int32_t)uistat.value));
     break;
-  case KM_DRIVE:
-    uistat.value = setting.rx_drive;
-    plot_printf(uistat.text, sizeof uistat.text, "%3ddB", ((int32_t)uistat.value));
-    break;
   case KM_LOWOUTLEVEL:
     uistat.value = get_level();           // compensation for dB offset during low output mode
     int end_level =  ((int32_t)uistat.value)+setting.level_sweep;
@@ -2422,9 +2417,6 @@ set_numeric_value(void)
   case KM_REPEAT:
     set_repeat(uistat.value);
     break;
-  case KM_DRIVE:
-    set_rx_drive(uistat.value);
-    break;
   case KM_LOWOUTLEVEL:
     set_level(uistat.value - setting.offset);
     break;