User's Manual

TB8100 Calibration Kit User’s Manual Calibrating the Supply Voltage 27
VSWR The VSWR (Voltage Standing Wave Ratio) is monitored at the RF output of
the PA during calibration. The software will not allow calibration into a load
VSWR > 1.3:1. If a calibration step cannot be stored, check that the load
VSWR is <1.3:1. It is recommended that the load should have an input
VSWR <1.2:1.
Calibrating the Supply Voltage
The Calibrate Supply Voltage procedure stores DAC values for a set of
different PA supply voltages. These values are used by the PA’s high and low
voltage alarms and for power foldback and shutdown.
Calibrating the supply voltage is only done if you have replaced the PA control
board or its EEPROM IC. An accredited service center must first re-program
the PA with its product code, PA type, and serial number. All other PA
calibration procedures also become necessary.
Equipment ■ Variable voltage power supply
■ Made-up adapter cable to connect the PA power input to the power supply,
with a “Chocolate block” screw connector at one end and (for example)
banana plugs at the other.
Important: Do not attempt this procedure without a variable voltage power
supply. You could be left with a PA that will not transmit.
To calibrate the PA power supply voltage
1. Connect the calibration kit to the base station.
2. Connect the variable voltage power supply to the PA as follows. (The PA
can be in or out of the subrack, as long as it is connected via the I2C bus.),
a. Remove the PA power connector from the socket in the PMU.
b. To make sure that you don’t re-connect the power cable with the wrong
polarity, mark the green connector to indicate which side is positive and
which is negative.
c. Remove the PA’s power cable from the green connector and connect it
to the “Chocolate block” screw connector on the made-up cable.
d. Connect the other end of the cable to the variable voltage power supply.
3. Select the PA calibration tab, and double-click Calibrate Supply Voltage.
The Calibrate Supply Voltage wizard appears.
4. Check that everything is connected correctly, and then click Next.
5. Set the power supply to 24.00 V as instructed, and then click Next. The PA
stores the DAC equivalent of the voltage you supplied and the wizard moves
to the next step.
6. Follow the wizard instructions (Steps 3-5) to store DAC values for 26, 30,
and 32 V. If desired, you can click Back to repeat a step.
7. When the wizard indicates that calibration is completed, click Finish.
The icon beside Calibrate Supply Voltage in the PA Calibration tab
indicates that this task is complete.
8. Re-connect the PA’s power cable to the green connector, using the marks
you made to ensure that you connect the wires the right way round.
9. Re-connect the PA to the PMU.