Atec Agilent-8563E - Manual (Page 130)

ESG Family Signal Generators Adjustments
ALC Modulation Driver Bias Calibration
Calibration Guide 5-33
ALC Modulation Driver Bias Calibration
Description
This test adjusts the ALC MOD DRV BIAS DAC on the output board. This DAC is used to
control the bias current to the ALC modulator driver. It is primarily used to accommodate
unmatched V
BE
values in the drives, but has a strong influence on modulator gain. This
test adjusts the DAC until the ALC modulator gain is balanced around its nominal design
center. The results are stored as a calibration array in the signal generator’s firmware.
Required Test Equipment
• None
Procedure
1. Preset the signal generator.
2. Follow the instructions as they appear on the controller’s display.