making 'second' numbering scheme the default for concat_ports, as the one being used by ** cascade operator
@@ -2934,7 +2934,7 @@ def overlap(ntwkA, ntwkB):
return ntwkA.interpolate(new_freq), ntwkB.interpolate(new_freq)
-def concat_ports(ntwk_list, port_order='first', *args, **kw):
+def concat_ports(ntwk_list, port_order='second', *args, **kw):
'''
Concatenate networks along the port axis
