Mod Source Relative Gain Calibration

(E8267D, E8663D with Option UNT and without Option UNY, and E8257D with Option UNT and without Option UNY and without Option HNY and E8257N Only)

This adjustment corrects for the differences in the FM source signal paths on the A11 Analog/Pulse Modulation Generator.

During this adjustment, scaling factors are determined for each FM source signal path for a given modulation signal level. The FM deviation is the same and independent of the signal source or signal path. Scaling factors are applied to the FM_SCALE_DAC on the A11 Analog/Pulse Modulation Generator.

The adjustment starts by setting the signal generator to 1 GHz with an FM deviation of 117.1875 kHz. The INT1 path is selected and the modulation level is set to 0 V. The output frequency is measured using a frequency counter and stored. The modulation level is then changed to -2 V and the output frequency is measured. The difference between the two frequencies is compared to a target deviation and used to determine a scaling factor. The routine is repeated for the INT2 path. The process for calibrating EXT1 and EXT2 paths and determining the scaling factors is the same except that a function generator is used to provide a modulation level of 1 V and a digital multimeter is used to set the modulation level.

Test Equipment

Preferred Model

Alternate Model(s)

Digital Voltmeter

3458A Opt 002

 

Frequency Counter

53230A Opt 010 and (106 or 115)

53132A Opt 010 and (050 or 124)

Function Generator

33250A

33120A opt 001

 

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 Ext 1 Input

Setup for Ext 2 Input

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.