Fluke 5790B, Service Manual

Page: 72 / 172

5790B
Service Manual
3-34
Table 3-9 shows the combination of the attenuators required to scale the
input signal properly for each range.
Table 3-9. Attenuators Required for Each Range
Range Attenuators 5790B Input
7 V None 3.2 V
2.2 V (1) 10 dB 1 V
700 mV (1) 20 dB 320 mV
220 mV (1) 20 dB + (1) 10 dB 100 mV
70 mV (2) 20 dB 32 mV
22 mV (2) 20 dB + (1) 10 dB 10 mV
7 mV (3) 20 dB 3.2 mV
2.2 mV (3) 20 dB
+
(1) 10 dB 1 mV
4. All ranges are calibrated in the similar manner. The calibration program
will prompt you at each step as to what frequency to apply.
5. From the Setup Menu>Calibration screen, push the “Adjust AC All
Wideband” softkey. The flatness calibration program starts with the 7 V
range.
6. To establish a 1 kHz reference at the beginning of each range, set the
5730A to 3.2 V and 1 kHz apply the appropriate attenuation as indicated
in Table 3-9 to obtain the correct input magnitude for the current range.
7. Push the “Continue” softkey. The 7 V 1 kHz reference will be measured
and the calibration program will continue the 7 V 10 Hz step.
8. Set the 5730A to 3.2 V at 10 Hz and adjust the 5730A to the total error
value at 10 Hz that was recorded in Table 3-8 during source
characterization.
9. Push the [Continue] key and the system will calibrate the range at 10 Hz
and step to the 50 Hz calibration point.
10. Set the 5730A to 50 Hz and adjust the 5730A to the total error value at
50 Hz that was recorded in Table 3-8 during source characterization.
11. Push the [Continue] key and the system will calibrate the range at 50 Hz
and step to the 400 Hz calibration point.
12. Proceed through the range at each calibration point frequency in the
same manner as steps 10, 11, and 12 by applying the proper frequency
and total error values (Note that the total error value is the sum of the
errors of the 5730A and all attenuators used for that range and
frequency).
13. When the calibration program has completed all the steps in the 7 V
range, it will step to the beginning of the 2.2 V range at the 1 kHz
reference.
14. Install the 10 dB attenuator as required by Table 3-9 for the 2.2 V range.
15. Establish the 1 kHz reference for this range by again setting the 5730A to
3.2 V at 1 kHz and apply the appropriate attenuation as indicated in Table