FM 1/2 Path Ratio Gain Calibration

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

This adjustment calibrates the A11 Pulse/Analog Modulation Generator FM 1 and FM 2 paths for equal gain.

During this adjustment, a function generator and a digital voltmeter are connected to the EXT 1 input of the signal generator and a frequency counter is connected to RF output. The signal generator is set to 525 MHz and 0 dBm output. The function generator is set for a 1 V DC output. The FM 1 path is set to EXT 1 and DC-coupled, while the RF output frequency is measured and used as the target value for the FM 2 adjustment. Next, the FM 2 path is set to EXT 1 and DC-coupled. The FM 2 path sensitivity is determined by measuring the RF output frequency with the FM_SCALE_DAC set to two different values. The FM_SCALE_DAC correction value is then determined using the RF output frequencies and DAC values. The new FM_SCALE_DAC value is verified and stored.

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 FM 1/2 Path Ratio Gain 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.