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NI PXIe-5694 Calibration Procedure
16. Calculate the NI 5694
gain
using the following equation:
Gain
=
Digitizer Power
+
Digitizer Cable Loss
-
Digitizer Frequency Response
-
Input Power
Note
Refer to Table 5 for the characterized digitizer cable loss.
17. Record the calculated gain to the NI 5694 EEPROM along with the RF source 1 frequency.
18. Repeat steps 13 through 17 for IF Attenuation Table Index values from 1 to 25, with a step
size of 1.
19. Repeat steps 10 through 18 for each of the following IF filter frequency settings:
•
5 MHz
•
1.4 MHz
•
400 kHz
•
110 kHz
20. Reconfigure the NI 5694 to enable step gain.
21. Reconfigure RF source 1, adjusting the power level to -15 dBm.
22. Repeat steps 10 through 19 with the new settings.
23. Reconfigure the NI 5622 digitizer as follows:
•
DDC center frequency: 21.4 MHz
•
Bandpass filter enabled: FALSE
24. Reconfigure the NI 5694 as follows:
•
Step gain: Disabled
•
IF conditioning downconversion: Enabled
25. Repeat steps 10 through 19 with the new settings and the following changes:
•
In step 15, query the digitizer response at 21.4 MHz instead of 193.6 MHz
•
In step 19, add 30 kHz to the list of frequencies to be iterated over
26. Reconfigure RF source 1, adjusting the power level to -25 dBm.
27. Reconfigure the NI 5694, enabling step gain.
28. Repeat steps 10 through 19 with the new settings and the following changes:
•
In step 15, query the digitizer response at 21.4 MHz instead of 193.6 MHz
•
In step 19, add 30 kHz to the list of frequencies to measure
29. Close the IF attenuation calibration step.
30. Close the external calibration session.