Index: ammosreader/PDW.py
===================================================================
--- ammosreader/PDW.py	(revision e4e63a33bb3ac7e25cde7abca3d43e55f42eadb4)
+++ ammosreader/PDW.py	(revision ef05d469ed714d84c764862f055210252a13d3f3)
@@ -141,5 +141,5 @@
         self.pdw_format_identifier = pdw_format_identifier
         self.center_frequency = center_frequency #
-        self.is_valid = is_valid #
+        self.__is_valid = is_valid #
         self.is_pulse = is_pulse #
         self.level_unit = level_unit #
@@ -169,5 +169,5 @@
                   "Center frequency: " + str(self.center_frequency) + " KHz\n")
 
-        if self.is_valid:
+        if self.__is_valid:
             output += "Signal: Valid\n"
         else:
@@ -221,4 +221,7 @@
 
         return output
+
+    def is_valid(self):
+        return self.__is_valid
 
     def to_json(self):
@@ -226,5 +229,5 @@
                 'FORMATIDENTIFIER': self.pdw_format_identifier,
                 'center frequency': self.center_frequency,
-                'VALID': self.is_valid,
+                'VALID': self.__is_valid,
                 'PULSE': self.is_pulse,
                 'PULSELEVEL': self.pulse_level_or_pulse_field_strength,
Index: ammosreader/PPDWContainer.py
===================================================================
--- ammosreader/PPDWContainer.py	(revision e4e63a33bb3ac7e25cde7abca3d43e55f42eadb4)
+++ ammosreader/PPDWContainer.py	(revision ef05d469ed714d84c764862f055210252a13d3f3)
@@ -16,10 +16,14 @@
             self.signals = signals
 
+        self.name = name
+
     def __str__(self):
         return "\n".join(["Number of pulses:" + str(len(self.signals)),
+                          "Number of invalid pulses:" + str(self.number_of_invalid_pulses()),
                           "Start time:" + str(self.start_time()),
                           "End time:" + str(self.end_time())])
 
     def add(self, a_pdw):
+        # print(a_pdw)
         self.signals.append(a_pdw)
 
@@ -34,4 +38,10 @@
         print(datetime.now())
         return pulse_dict
+
+    def number_of_invalid_pulses(self):
+        return sum(not each.is_valid() for each in self.signals)
+
+    def without_invalids(self):
+        return PPDWContainer(self.name, [each for each in self.signals if each.is_valid()])
 
     def julian_date_string(self):