5-14
888-2463-001
3/6/08
WARNING: Disconnect primary power prior to servicing.
Diamond Series™
Section 5 Maintenance and Alignments
5.5.4
PA Cabinet Combiner Reject Calibration
For transmitters with 2 or more PA Cabinets, there will be 1 or more reject loads on the
combiner. RF samples from these loads are sent to the detector in the Control Cabinet.
These detectors are calibrated for 4Vdc output when the reject load is dissipating
maximum power. This is then calibrated on the GUI as 100%.
STEP 1
The first step is to get maximum rf into the detector by shutting off a PA
Cabinet with the other cabinet(s) operating at nominal power output.
a.
For transmitters with 3 or more PA Cabinets, there is one reject load
for each cabinet. Simply shut off one cabinet to calibrate the detector
for that particular reject load.
b.
For 2 PA Cabinet combiners, there is only one reject load. Turn off
either PA cabinet to calibrate the reject load.
STEP 2
Go to the Power Calibrations screen shown in Figure 5-3. Check the
detector voltage reading for the Reject load to be calibrated. If it is 4V
(+/- 0.5V) the rf detector requires no adjustment and you can continue
on with the next step to finish the software calibration. If it is not within
this range then you will need to refer to paragraph "5.5.6 RF Detector
Adjustment" on page 5-21 to adjust the detector, then return here to
finish the calibration.
STEP 3
Verify approximately 4Vdc appears on the GUI Power
Calibrations screen for the Reject load you are calibrating.
STEP 4
Press the “Rej” button for the load you are calibrating.
STEP 5
Using the INCREASE/DECREASE and FAST/SLOW
buttons, change the percent reading on the calibration screen to 100%.
Note that this does not change the voltage reading into the GUI.
STEP 6
To save this new calibration factor, you must press “Save Data”.
STEP 7
If the detector was adjusted, be sure to return JP1 to the normal position,
pins 1-2 and secure the detector assembly.
