> > 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? > > That's not exactly true if you think about it. Since pstn lines are > typically copper based and have a varying resistance based on the length > and guage of copper, the copper resistance will vary from almost zero > (close to CO) to values over 1000 ohms. That certainly does _not_ change > the AC impedance of the line (regardless of its length); its still 600 > ohms. > > I don't recall for sure, but I'm fairly certain the impedance is relative > to 1,000 hz tone. > Yes, I get your point - however from the FXO point of view, the resistance will be copper + the exchange port resistance. But this may not have a significant impact. Well this means the transformer is the only idea 'left on the table' for me now ;)
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
