diff --git a/CAL/CalibrationCommon/lib/datacontainers/holography_datatable.py b/CAL/CalibrationCommon/lib/datacontainers/holography_datatable.py
index 7146ce828747bfcbc08b435055a78e4bc97d8756..0278ff0f7f3048b13eb2be2d203b6268a643d5e7 100644
--- a/CAL/CalibrationCommon/lib/datacontainers/holography_datatable.py
+++ b/CAL/CalibrationCommon/lib/datacontainers/holography_datatable.py
@@ -89,7 +89,7 @@ class HolographyDataTable(LazyH5Table):
         try:
             self.__get_index_arrays()
         except KeyError:
-            logger.debug('uri missing creating datable at: ' + self.uri)
+            logger.debug('uri missing, creating datable at: ' + self.uri)
 
     def __get_index_arrays(self):
         """
@@ -109,12 +109,12 @@ class HolographyDataTable(LazyH5Table):
         # I select the first reference station just for convenience to iterate on the third level
         first_frequency = frequencies_string[0]
         beam_numbers = {beam_number for beam_number in self.h5_file[self.uri]
-        [first_frequency]
-        [first_reference_station]}
+        [first_reference_station]
+        [first_frequency]}
 
-        self._frequencies = set(sorted(map(float, frequencies_string)))
-        self._reference_stations = reference_stations
-        self._beam_numbers = set(sorted(map(int, beam_numbers)))
+        self._frequencies = tuple(sorted(map(float, frequencies_string)))
+        self._reference_stations = tuple(reference_stations)
+        self._beam_numbers = tuple(sorted(map(int, beam_numbers)))
 
     @property
     def frequencies(self):
@@ -173,7 +173,7 @@ class HolographyDataTable(LazyH5Table):
         reference_station, frequency, beam_number = key
 
         self._frequencies.add(float(frequency))
-        self._reference_stations.add(frequency)
+        self._reference_stations.add(reference_station)
         self._beam_numbers.add(int(beam_number))
 
         super().__setitem__((reference_station,
@@ -184,13 +184,14 @@ class HolographyDataTable(LazyH5Table):
         for frequency in self._frequencies:
             for station in self._reference_stations:
                 for beam in self._beam_numbers:
-                    yield (float(frequency), station, int(beam)), \
+                    yield (station, float(frequency), int(beam)), \
                           self.__getitem__((station, frequency, beam))
 
     def keys(self):
         key_set = set()
-        for frequency in self._frequencies:
-            for station in self._reference_stations:
+
+        for station in self._reference_stations:
+            for frequency in self._frequencies:
                 for beam in self._beam_numbers:
-                    key_set.add((frequency, station, beam))
+                    key_set.add((station, frequency, beam))
         return key_set