Hello!
I'm having an echo problem with a TDM card. The TDM card is being fed by a channel bank just 12 or so feet away. When you put an analog handset on the line, both the RX and TX volume seem to be just fine. However, when I use the TDM card, I have to have an rxgain of 13.5, and even then, the audio is relatively quiet. I'm also getting echo on these lines, so I have turned the txgain down as low as I can and still be heard. Right now, it's at -6, but it will have to come up some because that is too quiet. But I still have echo.
I am in the middle of trying to get a milliwatt test line to calibrate the rxgain properly. However, this won't help me with the txgain, will it? How can I properly calibrate the txgain? By ear? Or is there a more scientific method?
For example, once I have the rxgain calibrated for all of the lines, could I then call into, say, Zap/3 from Zap/4 and run Milliwatt() on Zap/3 and use ztmonitor on Zap/4 to calibrate it? I'm sure it's not perfect, but would it be close enough?
A second question: doesn't it seem wrong that my rxgain and txgain are so far off when I'm just talking to a channel bank 12 feet away? I sure don't have cable loss. It sure seems like the impedance is way off or something. Is there a way to test this further, rather than just cranking up the gain? My guess is that using the milliwatt line will just tell me to make the rxgain higher, which will probably just make the echo issues worse...
Tim Massey
_______________________________________________ --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
