> 5. Placing ferrite cores on the phone cables. Do either of the phone lines in question have DSL on them?
If so, a ferrite core (which will block common-mode RF signals) probably won't help much, if at all. DSL is a differential-mode signal, and its frequency content starts down in the tens of kHz. Ferrite cores are usually intended to block much higher frequency interference, and won't have enough inductance to help much with DSL signals. What I would suggest, is that you get yourself a couple of DSL "microfilters"... plug them into the A400P FXO ports, and plug the lines into the filters. These sorts of filters are designed specifically to block DSL differential- mode signals from getting into analog-phone circuits, and they will also be fairly effective against other forms of low-frequency-RF noise. -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
