Low Band ALC Modulator Calibration

The Lowband ALC Modulator Calibration adjusts 2 DACs so the ALC off level accuracy is satisfactory. In general the BIAS DAC (LB OFFSET) compensates for the frequency response of the RF path, while the GAIN DAC (LB BIAS) sets the slope of the modulator.

 

Test Equipment

Preferred Model

Alternate Model(s)

Function Generator
Only for E8267D Opt H16, 016, HBQ, or HBR

33250A

33120A Opt 001

50 Ohm Terminator

Depending on the DUT RF Output Connector, choose:

85138B (2.4mm)
or 909D (3.5mm)
or 909A, Opt 012 (Type N)

20 dB attenuator

 

Connections and Setup Procedures

  • All test equipment requires a 30 minute warmup period to ensure accurate performance.

  • In the following test setup, cables are designated as solid lines and direct connections are designated as dashed lines.

  1. Connect all test equipment as shown.

  2. Connect GPIB cables to all GPIB-controlled test equipment.

  3. While performing this adjustment, follow all instructions on the controller display.

 

Setup for Low Band ALC Modulator Calibration

 

Setup for Low Band ALC Modulator Calibration (E8267D with Option H16, 016, HBQ, or HBR)

 

In Case of Difficulty

If this adjustment fails, perform the following steps in order:

  1. Check the equipment setup (see above). If the setup is incorrect, make the necessary corrections and rerun the adjustment.

  2. If this adjustment fails with the equipment set up properly, refer to the troubleshooting section of the signal generator's service guide. If you do not have a printed copy of the service guide (Option OBW), one is available either on the CD-ROM that came with your signal generator shipment or on the Keysight Website.

  3. If you cannot correct the problem using the troubleshooting procedures in the Service Guide, obtain service from Keysight Technologies. Refer to Contacting Keysight Technologies.