User's Manual

24 Audio Calibration MB8100-90-00-806 © TEL 2004
To calibrate the balanced input and output lines
1. Ensure you are already connected to the reciter.
2. Select the Reciter Calibration tab, and double-click Balanced Line
Calibration. The Balanced Line Calibration Wizard appears.
3. Attach an AC millivoltmeter and terminate the balanced output in 600
ohms (either using the load on the CTU or looping the balanced output to
the balanced input), and then click Next.
4. Adjust the slider in the dialog box until the audio level on the millivoltmeter
reads 1 V
PP (0.354 VRMS) to calibrate the balanced line output, and then
click Next.
Note: Click Coarse to roughly adjust the audio level, and once you
get within range, click Fine for more precise control over the
settings. To move up or down 10 mV
PP, click either side of the
slider bar.
The balanced output is now calibrated.
5. Ensure that the 600 ohm load on the CTU is turned off, and then connect
the balanced output to the balanced input. Click Finish.
The balanced input is now calibrated.
When you have finished calibrating the balanced lines, the icon on the
Reciter Calibration tab indicates that this task is complete.
Calibrating the Unbalanced Lines
Calibrating the unbalanced lines adjusts their gain, so that when you set line
levels using the TB8100 Service Kit software, the actual line level correctly
reflects the Service Kit settings. (Refer to the TB8100 Service Kit User’s Manual
for further information.)
Equipment ■ Calibration test unit (CTU)
■ AC millivoltmeter
Setup for
Unbalanced Line
Out
1
6
3
4
2
5
1 Reciter 3 CTU 5 Unbalanced line output
2 25-way cable 4 System interface port 6 AC millivoltmeter