| Cnavarro, I'm more than happy to go along with the idea of checking the line current but please help me with the test conditions and current upper and lower limits. Under what loop / load conditions should I do my readings? For example, should it be with a fixed loop resistance (600 Ohms)? The question of line current (except for very low currents / high line resistance) has never been an issue to me here in the UK and I have been involved with PBXs since 1980. But I'm always willing to try another idea. Regards, Rod |