FM Scale Offset Calibration

(E8257D, E8267D, E8663D with Option UNT and E8257N Only)

This adjustment calibrates the FM Scale DAC on the A11 Pulse/Analog Modulation Generator so that there is no change in output frequency when the FM Offset DAC is switched.

During this adjustment, the effects associated with changes in the FM Scaling circuit due to changes in noise gain caused by changes in the FM Offset circuit, are calibrated out. The adjustment is made by setting the FM_SCALE_DAC to a low and high gain level while setting the FM2_OFFSET_DAC to minimum and then maximum conditions. At each DAC condition, the frequency is measured and the results are used to determine a value that is stored.

Test Equipment

Preferred Model

Alternate Model(s)

Frequency Counter

53230A Opt 010 and (106 or 115)

53132A Opt 010 and (050 or 124)

 

Connections and Setup Procedures

  • With the exception of the 53132A Option 050 or 124, or the 53230A Option 106 or 115 frequency counter, all test equipment requires a 30 minute warmup period to ensure accurate performance.

  • The frequency counter must be plugged into the AC power line for at least 24 hours before testing begins.

  • 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 FM Scale Offset Calibration

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.