Powerware Model V-2000B - Manual (Page 110)

108 = Maintenance
Alternate Calibration Procedure
If the calibration test clip titled z1K_TONE is not found on the Image Server’s disk, it is still
possible to accurately calibrate the audio channels.
1. Position the jumper block J5 and J6 for Channel 1 output to obtain a digital output.
2. Using the On-Screen graphic user interface, place server Channel 1 in the E-E
mode, so that an input signal will appear at its output.
3. Use the audio generator to apply a 1 kHz sine wave at a level of +4 dBu to analog
audio Input 1-L.
4. While observing the digital output level of audio Channel 1-L, adjust input gain trim
pot RV2 until a level of –20 dBFs is obtained. (+4 dBu is 20 dB below full scale,
which is +24 dBu; therefore it reads 20 dB below full scale or Fs.)
5. Repeat steps 2 through 4 for analog audio Input 1-R, while adjusting input gain trim
pot RV1.
The server’s input gain is now calibrated. It remains to calibrate each analog output for unity
gain using the following procedure:
6. Position all audio output jumper blocks to obtain analog outputs.
7. Using the graphic user interface, verify that server Channel 1 is in E-E mode, so that
an input signal will appear at its output.
8. Apply a 1 kHz sine wave at a level of +4 dBu to analog audio Input 1-L.
9. While observing the output level of audio Channel 1-L, adjust output gain trim pot
RV4 until a level of +4 dBu is obtained.
10. While observing the output level of audio Channel 1-R, adjust output gain trim pot
RV3 until a level of +4 dBu is obtained.
11. Make a 1-minute clip of the 1 kHz sine wave at a level of +4.00 dBu. Save this clip
for future use in calibrating the server.
12. Play this clip from Channel 2 and repeat ste ps 9 and 10 to adjust the gain of the left
and right outputs.
13. Play the clip created in step 11 from Channel 3 and repeat steps 9 and 10 to adjust
the gain of the left and right outputs.
The server’s output gains are now calibrated, and the entire sequence of the preceding steps
have established a gain of unity through the server.
Another method is to use digital input with a digital sine wave of –20dBFS to calibrate analog
outputs 1 & 2 and create the reference clip.