Got a customer with an SL1100 with 4 CO lines from Spectrum hooked up to the system. Line 1 has noticeable static when on a call with a system phone. Other lines appear to be ok. I tested line 1 with my butt set by isolating line 1 and connecting to the spectrum demarc. No static. So far I've run program 90-68-01 (reset). I've also measured loop current which was at 39ma, on the high side. Aha, I figured, I'm onto something. Contacted Spectrum who didn't know what loop current was but will dispatch a tech tomorrow to, I guess, twiddle their thumbs. Contacted NTAC who advised lower gain in 14-01-02 and 03. They also advised I lower codec in program 81-07-01 from 0 to 1 (reset). It helped but static is still there. my next step I guess is to pad the lines, but if I do what size resistor would be needed. Does anyone else have any theories on this?

St Petersburg