diff --git a/main.c b/main.c
index ddbd41c..cae46ce 100644
--- a/main.c
+++ b/main.c
@@ -965,7 +965,7 @@ VNA_SHELL_FUNCTION(cmd_scan)
 {
   uint32_t start, stop;
   uint32_t points = sweep_points;
-  int i;
+  uint32_t i;
   if (argc < 2 || argc > 4) {
     shell_printf("usage: scan {start(Hz)} {stop(Hz)} [points] [outmask]\r\n");
     return;
@@ -979,33 +979,11 @@ VNA_SHELL_FUNCTION(cmd_scan)
   }
   if (argc >= 3) {
     points = my_atoi(argv[2]);
- //   if (points <= 0 || points > POINTS_COUNT) {
- //     shell_printf("sweep points exceeds range "define_to_STR(POINTS_COUNT)"\r\n");
- //     return;
- //   }
-  }
-
-  if (argc==4 && my_atoui(argv[3]) == 16) {
-    int old_step = setting.frequency_step;
-    float f_step = (stop-start)/ points;
-    setting.frequency_step = (int32_t)f_step;
-    streamPut(shell_stream, '{');
-    dirty = true;
-    for (int i = 0; i<points; i++) {
-      if (operation_requested)
-        break;
-      float val = perform(false, i, start +(int32_t)(f_step * i), false);
-      streamPut(shell_stream, 'x');
-      int v = val*2 + 256;
-      streamPut(shell_stream, (uint8_t)(v & 0xFF));
-      streamPut(shell_stream, (uint8_t)((v>>8) & 0xFF));
-    // enable led
+    if (points <= 0 || points > POINTS_COUNT) {
+      shell_printf("sweep points exceeds range "define_to_STR(POINTS_COUNT)"\r\n");
+      return;
     }
-    streamPut(shell_stream, '}');
-    setting.frequency_step = old_step;
-    return;
   }
-
   set_frequencies(start, stop, points);
 #ifdef __VNA__
   if (cal_auto_interpolate && (cal_status & CALSTAT_APPLY))
@@ -2284,6 +2262,7 @@ static const VNAShellCommand commands[] =
 #endif
 //  {"gamma"       , cmd_gamma       , 0},
     {"scan"        , cmd_scan        , CMD_WAIT_MUTEX},
+    {"scanraw"     , cmd_scanraw     , CMD_WAIT_MUTEX},
     {"sweep"       , cmd_sweep       , 0},
     {"test"        , cmd_test        , 0},
     {"touchcal"    , cmd_touchcal    , CMD_WAIT_MUTEX},
diff --git a/sa_cmd.c b/sa_cmd.c
index 88f43a9..af50c4f 100644
--- a/sa_cmd.c
+++ b/sa_cmd.c
@@ -464,3 +464,41 @@ VNA_SHELL_FUNCTION(cmd_correction)
   config.correction_value[i] = v;
   shell_printf("updated %d to %d %.1f\r\n", i, config.correction_frequency[i], config.correction_value[i]);
 }
+
+VNA_SHELL_FUNCTION(cmd_scanraw)
+{
+  uint32_t start, stop;
+  uint32_t points = sweep_points;
+  if (argc < 2 || argc > 3) {
+    shell_printf("usage: scanraw {start(Hz)} {stop(Hz)} [points]\r\n");
+    return;
+  }
+
+  start = my_atoui(argv[0]);
+  stop = my_atoui(argv[1]);
+  if (start > stop) {
+      shell_printf("frequency range is invalid\r\n");
+      return;
+  }
+  if (argc == 3) {
+    points = my_atoi(argv[2]);
+  }
+  int old_step = setting.frequency_step;
+  float f_step = (stop-start)/ points;
+  setting.frequency_step = (int32_t)f_step;
+  streamPut(shell_stream, '{');
+  dirty = true;
+  for (uint32_t i = 0; i<points; i++) {
+    if (operation_requested)
+      break;
+    float val = perform(false, i, start +(int32_t)(f_step * i), false);
+    streamPut(shell_stream, 'x');
+    int v = val*2 + 256;
+    streamPut(shell_stream, (uint8_t)(v & 0xFF));
+    streamPut(shell_stream, (uint8_t)((v>>8) & 0xFF));
+  }
+  streamPut(shell_stream, '}');
+  setting.frequency_step = old_step;
+}
+
+