Index: ammosreader/PDW.py
===================================================================
--- ammosreader/PDW.py	(revision 083cf10911e9234d0ed15a898c7a2fa9ba56b509)
+++ ammosreader/PDW.py	(revision df4d123b82e4a0d47bfeb33c98fc0fbf022f117c)
@@ -61,5 +61,5 @@
         modulations = {0: 'Unknown', 1: 'Unmodulated', 2: 'FM', 3: 'LFM', 4: 'PSK-2', 5: 'PSK-3', 6: 'PSK-4',
                        7: 'PSK-m', 8: 'NLFM', 9: 'SFM', 10: 'TFM', 11: 'Pulse too short'}
-        modulation = modulations[int(sixth_entry_bit_string[7:12], 2)]
+        modulation = modulations.get(int(sixth_entry_bit_string[7:12], 2), 0)
         sector = int(sixth_entry_bit_string[28:32], 2)