> > Pull the clone card out of the system and look for the chipset numbers > on the card. Go to the chip manufacturers web site and find the specs > for that chip set. The specs will likely tell you the chipset was designed > for the US 600 ohm impedance telephone network, and if your country's > telco specs are different (which I'm very sure they are), through away > the clone card. Without proper impedance matching there isn't anything > your going to be do to fix the problem.
I can check the chip on monday, but local telco impedance requirements are 600 ohms - just like US. > > > > I'm thinking about playing around with increasing/decreasing resistance > > by placing additional resistors in the circut. Messy, but if it could > > help... What do you think? > > Adding resistance has nothing at all to with impedance matching. Resistance > will impact the DC loop, but not the AC impendance. The AC impedance is a > function of how the chipset was designed. > AFAIR, the impedance is not a simple factor, but a combination of passive resistance plus reactance - which usually varies within measured frequency range. Therefore channging the device resistance WILL change its impedance. I know the result will not be perfect, but at least i hope for better load match than it is now. I assume the specified impedance is required within PSTN frequencies which will be roughly 100-4khz, right? Marek _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
