Fix DLtype getting overwritten by dl_gain setter.

nexus/nexus.py

@@ -281,7 +281,7 @@ class StationNode(InventoryNode):
         for chan in (chan for chan in channels
                      if chan.code[1] in ('H', 'L', 'G', 'N')):
             try:
-                gain =  chan.response.response_stages[1].stage_gain
+                gain = chan.response.response_stages[1].stage_gain
             except (AttributeError, IndexError):
                 continue
             self.set_dl_gain(gain, keep_response=True)
@@ -294,14 +294,16 @@ class StationNode(InventoryNode):
         except ValueError:
             return
         for chan in self._inv_obj.channels:
-            try:
-                # If the used clicks in and out ignore
-                old_gain = chan.data_logger.gain
-                if old_gain == value:
-                    return False
-            except AttributeError:
+            if isinstance(chan.data_logger, Equipment):
+                try:
+                    old_gain = chan.data_logger.gain
+                    if old_gain == value:
+                        continue
+                except AttributeError:
+                    pass
+            else:
                 chan.data_logger = Equipment()
-                chan.data_logger.gain = value
+            chan.data_logger.gain = value
             if not keep_response:
                 chan.response = None
         return True