Fluke 5720A service manual Wideband Flatness Calibration Procedure

Calibration and Verification 3

Wideband Output Flatness Test

3-30. Wideband Flatness Calibration Procedure

This procedure is the only part of full verification that stores calibration constants in the Calibrator. This is not a verification test, it is a calibration procedure. Because this part of calibration is recommended to be done only every two years, the same interval as full verification, it is included here and not under Calibration earlier in this chapter and in Chapter 7 of the 5700A/5720A Series II Operator Manual.

Proceed as follows to perform wideband flatness calibration:

1.Connect the equipment as shown in Figure 3-12 and set the rear panel CALIBRATION switch to the ENABLE position.

2.Push the WBND button on the 5790A.

3.Call up the wideband flatness calibration routine on the Calibrator front panel, by pressing the softkey sequence SETUP MENUS, CAL, CALIBRATION and

WIDEBAND FLAT.

4.Enter the present ambient air temperature as prompted and press ENTER.

5.Place the Calibrator in OPERATE. Wideband flatness calibration starts with a 3V output at 1 kHz.

6.Push the SET REF soft key on the 5790A when the 5790A settles to a reading. This is the 3V reference value from which all other frequencies will be compared.

7.Push the ENTER button on the Calibrator, and, the frequency will advance to the next value.

8.Adjust the Calibrator output adjustment knob to bring the 5790A error display to 0 and press ENTER on the Calibrator. Repeat this step for each frequency through 30 MHz.

9.Push the CLEAR REF WBND soft key on the 5790A. The Calibrator wideband output changes to 1V at 1 kHz.

10.Push the SET REF soft key on the 5790A when the 5790A settles to a reading,. This is the 1V reference value from which all other frequencies will be compared.

11.Repeat steps 7 and 8 above for each frequency through 30 MHz.

12.Push the CLEAR REF WBND soft key on the 5790A. The Calibrator Wideband output changes to 300 mV at 1 kHz.

13.Push the SET REF soft key on the 5790A when the 5790A settles to a reading. This is the 300 mV reference value from which all other frequencies will be compared.

14.Repeat steps 7 and 8 above for each frequency through 30 MHz.

15.Push the CLEAR REF WBND soft key on the 5790A. The 5790A wideband output changes to 100 mV at 1 kHz.

16.Push the SET REF soft key on the 5790A when the 5790A settles to a reading. This is the 100 mV reference value from which all other frequencies will be compared.

17.Repeat steps 7 and 8 above for each frequency through 30 MHz. Only the 10 MHz, 20 MHz and 30 MHz points are adjusted.

18.Push the CLEAR REF WBND soft key on the 5790A. The 5790A wideband output changes to 30 mV at 1 kHz.

19.Push the SET REF soft key on the 5790A when the 5790A settles to a reading. This is the 30 mV reference value from which all other frequencies will be compared.

20.Repeat steps 7 and 8 above for each frequency through 30 MHz.

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