Fluke 5790A Service Manual page 122

5790A
Service Manual
Rolloff Worksheet Entry
30 MHz CAL Constant Name
Active Value
Default
(1) Active - Default (PPM)
(2) A55 Correction (PPM)
(3) Attenuator #1 Error (PPM)
(4) Attenuator #2 Error (PPM)
Total 1 2
3-42
Table 3-11. Wideband Amplifier Rolloff Adjustment Worksheet
F16_220MV_WB
3 4 (PPM)
13. Allow the A55 to stabilize, and then press the STORE and OFFSET keys on the
8506A DMM.
14. Press the "SET REF" softkey on the 5790A.
15. Set the 5700A to 30 MHz, and adjust the 5700A to bring the 8506A reading to 0.
16. Press the [NEW REF] button on the 5700A and dial in the 30 MHz correction for
the A55, the attenuators, and the current active calibration constant. You do this
by adjusting the 5700A knob for a 5700A error display of the same sign and
magnitude as the total error entry 220 mV range at the bottom of Table 3-11.
17. Raise the front of the guard cover and adjust C24 for a 5790A display of -3500
PPM 1000 PPM. (Use a Johanson #8777 tool or equivalent).
18. Set the 5700A to standby.
19. Replace the 10 dB attenuator with a 20 dB attenuator to give a total attenuation
of 40 dB.
20. Set the 5790A to the 70 mV range.
21. Set the 5700A to 3.2 V at 1 kHz, operate.
22. The 5790A will read approximately 32 mV.
23. Allow the A55 to stabilize and then press the STORE and OFFSET buttons on
the 8506A DMM.
24. Press the "SET REF" softkey on the 5790A.
25. Set the 5700A to 30 MHz, and adjust the 5700A to bring the 8506A reading to 0.
26. Press the [NEW REF] button on the 5700A and dial in the 30 MHz correction for
the A55, the attenuators, and the current active calibration constant. You do this
by adjusting the 5700A knob for a 5700A error display of the same sign and
magnitude as the total error entry 70 mV range at the bottom of Table 3-11.
27. Raise the front of the guard cover and adjust C20 for -3500 PPM 1000 PPM.
28. Set the 5700A to standby and remove the A55 and attenuators.
29. Replace the covers and screws.
220 mV Range 70 mV range
F16_70MV_WB