On 01/03/12 19:07, Dave Platt wrote:
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.
Hi Dave and thanks for the suggestion. Although the lines don't have
ADSL on them (we have a separate line for that) - I've tried ADSL
filters on the them anyway. I even chained two filters to see if it will
have any effect. I'm afraid the noise is still the same.
Regards
--
_____________________________________________________________________
-- 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
