7
Operation
(continued)
the Mix<Caller and Caller output on PBXport and connect
your handset back to the telephone. Any audio sent into the
Send input will still be active on the Mix output based upon
your settings.
Send Signal Level
The Send LEDs display the signal level as it goes out over
the phone line. The goal is to drive the phone line at high
enough levels to avoid phone line noise, but not so loud as to
cause excessive clipping. Adjust the send level control until
you see occasional flashes of the red -3dB peak Send LED.
These flashes should occur during loud speech bursts only. If
the red LED stays lit for extended periods you can assume
that much of your speech is being clipped or distorted. In this
case you should back down on the Send volume control or
the mixer output that is causing the clipping.
Receive Signal Level
The receive LEDs display the signal coming from the phone
line and out of the DSP. The Caller level control does not
change what you see on these LEDs. Adjust the Caller level
control to give you the best signal level at the output XLR. If
your telephone has an adjustable receiver volume control,
you should set this control to the "normal" position. If you at-
tempt to boost the level of the caller's voice using the handset
volume control on your telephone, you may cause PBXport to
become unstable. This instability would be caused by the in-
creased level of the transmit signal that becomes mixed with
the caller's voice.
Headphone Mix
The 1/4" headphone jack on the front of PBXport is used for
monitoring your call. This stereo jack contains a mix of both
sides of the conversation on each headphone channel. The
levels of this mix are determined by the Send>Mix<Caller vol-
ume controls. The overall audio level from this jack is deter-
mined by the Mix Monitor volume control.
