
6.3 Calibrating the Input Modules
6.3.1 Introduction
CompuCal™ Computerized Calibration:
Calibration of the console’s Input modules is
completely computer controlled. There are no trim pots to adjust. Calibration is
accomplished by running the console’s calibration program and patching the console’s
oscillator into module inputs at specified times.
6.3.2 Required Equipment
• A calibrated dBu meter.
• An external Sine Wave Oscillator or the console’s internal Sine Wave Oscillator. Turn
on the oscillator and allow it to stabilize 1/2 hour before calibration.
• A cable to interface the oscillator output to each module’s Tape Input via the patch bay
or 1/4" Stereo Phone Plug
• A cable to interface the oscillator output to each module’s CHAN path Insert Return via
the patchbay or 1/4" Stereo Phone Plug (wired to Ring only).
NOTE:
Oscillator pinouts are described in
Section 2
,
Installation
.
6.3.3 Calibrating Input Modules
Overview:
Module calibration has 4 basic steps:
1.
Aux 7/8 Pot Setup
2.
Meter Calibration
3.
Reference Level Acquisition
4.
VCA Calibration
Each step must be completed for all modules before continuing on to the next step. If at
any time, a module fails to complete a step,it can be excluded from further calibration by
pressing the module’s
Select
button When a module is excluded, default calibration
settings are used until the problem can be diagnosed and remedied, and the module
recalibrated.
During calibration, the LCD display shows progress reports and help messages. The
module Status LEDs display progress on a module basis.
■
Calibration Procedure
IMPORTANT:
Calibration data is stored in the console’s non-volatile RAM. Initiating the
calibration procedure overwrites existing calibration data with new calibration data.
Do
not initiate calibration unless you intend to complete the calibration process.
NOTE:
Modules must be set for +4 dBu operation during calibration. If your console is
set for -10 dBu operation, return the console to +4 dBu operation as described in
§6.2
.
Upon completing calibration, return the modules to -10 dBu operation.
Follow this procedure to calibrate Input Modules:
1.
Press
Misc
to display the Misc menu. Hold
Shift
and press
CAL
.
A warning
message is displayed.
Press
PROCEED
to continue or
EXIT
to abort
calibration.
2.
At this point you have the option to load previously saved calibration data (
LOAD
),
set all modules to standard factory calibration data (
DEFAULT
), or initiate the
calibration procedure (
CALIBRATE STEREO
or
MONO
).
Press
CALIBRATE STEREO
or
MONO
to initiate the calibration procedure.
You
may now press the
Select
button of individual modules that you want to calibrate
or press
ALL
to calibrate all modules.
3.
The first part of the calibration requires that the Aux 7 and 8 pots be set a specific
way to facilitate calibration. Set all module Aux 7 and 8 pots as follows:
Section 6 - Alignment and Maintenance
STATUS 18R
Operation and Maintenance Manual
6 - 2
August 1999
Meter
Solo
Group
Recall
Automation
Misc
-CALIBRATE- STATUS LOAD
STEREO MONO DEFLTS DONE
CAL LCD Menu
Meter
Solo
Group
Recall
Automation
Misc
AUXMUTE CAL HDWRE
FILE MASTER
MISC LCD Menu