As ring wires seem to cause problems in some locations, perhaps you could just insert a standard dongle filter on the internal NTE5 and use that to handle the ring facility?
Kind regards,
Walter
Yes you could Walter, or not connect the ring line at all at the external NTE (XNTE) But these are installations for others, so I keep to a standard form (IT is possible that the owner might move and take their SSFP with them and refit the original faceplate, and the lack of a ring line may cause problems for a new owner) Its not hard to remove the components or fit the link.