3/6/08
888-2463-001
5-9
WARNING: Disconnect primary power prior to servicing.
Section 5 Maintenance and Alignments
Diamond Series™
5.5
Power Calibration Procedures
There are basically 4 calibration procedures that could be required in the field:
•
Forward Power - For PA Cabinet and Total System Forward power calibration.
•
Reflected Power - For PA Cabinet and Total System Reflected power calibration.
•
Driver Forward Power - For Driver Output and PA Cabinet Input calibration.
•
Reject Load Power - For PA Module and PA Cabinet Combiner Reject Loads.
Calibration and/or replacement of the RF Detectors depends on their particular use.
Each PA Cabinet has 2 or more RF Detector assemblies depending on the number of PA
Modules. One or two (8 section) detectors are used on the circulator reject loads while
another monitors Cabinet input drive level, Cabinet Forward power and Cabinet
Reflected power. See the PA Cabinet Wiring Diagram (sheet 7) in Section 500 of the
Schematic Package. The Control Cabinet contains one (4 or 8 section) RF Detector
assembly for monitoring total system forward and reflected power, driver power and for
up to 5 cabinet combiner reject loads. Calibration procedures for each of these are
contained in the following paragraphs.
Please Read This Before Calibrating
The PA Cabinet is setup with a rear door interlock, that will allow the transmitter
to operate for 2 minutes after the door is opened (the fans will shut off). If the
voltage drops to zero while you are attempting to calibrate a detector, the
cabinet's RF power has probably turned off (as per the 2 minute door timer). If
that happens, close the cabinet door, press the transmitter ON button and the PA
Cabinet should return to normal operation. Then open the cabinet door and
resume calibration (this does not apply to Control Cabinet).
Switch S3-8 on the Cabinet Controller Board must be set to the OFF position
(this is its normal setting) to allow the rear PA Cabinet door to be opened and
still allow it to operate. If S3-8 is in the ON position, the PA Cabinet will shut off
as soon as the rear door is opened. For more information on External and Door
Interlocks see "Table 2-1 Settings for Dipswitch S3, Cabinet Controller" on page
2-14 or "5.10.3 Replacing the Cabinet Controller Board" on page 5-36.
