diff --git a/ntp_core.c b/ntp_core.c
index f21065d..60d433c 100644
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -196,6 +196,9 @@ struct NCR_Instance_Record {
 /* Maximum allowed stratum */
 #define NTP_MAX_STRATUM 15
 
+/* INVALID or Unkown  stratum from external server  as per the NTP 4 docs */
+#define NTP_INVALID_STRATUM 0
+
 /* ================================================== */
 
 static ADF_AuthTable access_auth_table;
@@ -539,7 +542,13 @@ transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
 
   /* Generate transmit packet */
   message.lvm = ((leap << 6) &0xc0) | ((version << 3) & 0x38) | (my_mode & 0x07); 
-  message.stratum = our_stratum;
+  if (our_stratum <= NTP_MAX_STRATUM) {
+    message.stratum = our_stratum;
+  } else {
+    /* (WGU) to handle NTP  "Invalid" stratum as per the NTP V4 documents. */
+    message.stratum = NTP_INVALID_STRATUM;
+  }
+ 
   message.poll = my_poll;
   message.precision = LCL_GetSysPrecisionAsLog();
 
@@ -983,6 +992,12 @@ receive_packet(NTP_Packet *message, struct timeval *now, NCR_Instance inst, int
     test6 = 1; /* Succeeded */
   }
 
+  /* (WGU) Set stratum to greater than any valid if incoming is 0 */
+  /* as per the NPT v4 documentation*/
+  if (message->stratum <= NTP_INVALID_STRATUM) {
+    message->stratum = NTP_MAX_STRATUM + 1;
+  }
+
   /* Test 7 checks that the stratum in the packet is appropriate */
   if ((message->stratum > REF_GetOurStratum()) ||
       (message->stratum > NTP_MAX_STRATUM)) {
diff --git a/rtc_linux.c b/rtc_linux.c
index 8765a12..dc5a15d 100644
--- a/rtc_linux.c
+++ b/rtc_linux.c
@@ -174,7 +174,7 @@ static double file_ref_offset, file_rate_ppm;
 /* ================================================== */
 
 /* Flag to remember whether to assume the RTC is running on UTC */
-static int rtc_on_utc = 0;
+static int rtc_on_utc = 1;
 
 /* ================================================== */
 
@@ -226,15 +226,18 @@ accumulate_sample(time_t rtc, struct timeval *sys)
     discard_samples(NEW_FIRST_WHEN_FULL);
   }
 
-  rtc_sec[n_samples] = rtc;
 
   /* Always use most recent sample as reference */
+  /* use sample only if n_sample is not negative*/
+  if(n_samples >=0)
+  {
   rtc_ref = rtc;
-
+  rtc_sec[n_samples] = rtc;
   rtc_trim[n_samples] = 0.0;
   system_times[n_samples] = *sys;
-  ++n_samples;
   ++n_samples_since_regression;
+  }
+  ++n_samples;
   return;
   
 }
@@ -742,7 +745,11 @@ handle_initial_trim(void)
   run_regression(1, &coefs_valid, &coef_ref_time, &coef_seconds_fast, &coef_gain_rate);
 
   n_samples_since_regression = 0;
-  n_samples = 0;
+
+  /* Set sample number to -1 so the next sample is not used, as it will not yet be corrected for System Trim*/
+
+  n_samples = -1;
+
 
   read_coefs_from_file();
 
@@ -866,6 +873,8 @@ read_from_device(void *any)
   int error = 0;
 
   status = read(fd, &data, sizeof(data));
+  if (operating_mode == OM_NORMAL)
+      status = read(fd, &data, sizeof(data));
   if (status < 0) {
     /* This looks like a bad error : the file descriptor was indicating it was
      * ready to read but we couldn't read anything.  Give up. */
diff --git a/sourcestats.c b/sourcestats.c
index fecba31..163a2eb 100644
--- a/sourcestats.c
+++ b/sourcestats.c
@@ -373,9 +373,9 @@ find_best_sample_index(SST_Stats inst, double *times_back)
 /* This defines the assumed ratio between the standard deviation of
    the samples and the peer distance as measured from the round trip
    time.  E.g. a value of 4 means that we think the standard deviation
-   is a quarter of the peer distance */
+   is four times the fluctuation  of the peer distance */
 
-#define SD_TO_DIST_RATIO 8.0
+#define SD_TO_DIST_RATIO 1.0
 
 /* ================================================== */
 /* This function runs the linear regression operation on the data.  It