Pretune

This adjustment is only performed if the ESG has Option UNJ. The purpose of this adjustment is to optimize the YO pretune voltage so the YO phase lock loop needs to apply minimal correction to achieve phase lock. During normal instrument operation, the YO Pretune DAC is used to set the YIG drive level prior to closing the PLL. This adjustment generates the offset and gain calibration constants which determine the YO Pretune DAC setting for a given YO frequency. For this calibration, the YO loop is opened and the Pretune DAC is changed to get the frequency as close as possible to the target frequency. This is done for a low YO frequency and a high YO frequency. Gain and offset terms are then calculated and stored.

Required Test Equipment

Test Equipment

Recommended Model

Alternate Model

Frequency counter

53230A Opt [106 or 115]

53132A Opt 010 and [050 or 124]
53131A Opt 010 and [050 or 124]

Connections and Setup Procedures
  • All test equipment requires a 30 minute warmup period to ensure accurate performance.
  • In the following adjustment 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.

 

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.