Agilent Technologies 8590 Series Service Manual page 623

CAL: GAIN FAIL (H)
During the
CAL AMPTD
ADC on the A16 processor/video assembly is too low. The error message
appears when the reference-level-calibration DAC, located on the A7
analog interface assembly, has been adjusted to its maximum of 255,
and the amplitude of the video signal remains below tolerance.
Related Assemblies
8590L and 8591E spectrum analyzers only: A3 input attenuator, A4
first converter, A5 second converter, A6 YTO, A7 analog interface, A9
third converter, A11 bandwidth filter, A12 amplitude control, A13
bandwidth filter, A14 log amplifier.
All other 8590 E-Series and L-Series spectrum analyzers: A3 front end,
A7 analog interface, A9 third converter, A11 bandwidth filter, A12
amplitude control, A13 bandwidth filter, A14 log amplifier.
Troubleshooting Hints
The routine checks the amplitude of the video signal as it
CAL AMPTD
adjusts the A7 reference-level-calibration DAC. Normally, the
video-signal amplitude should move within tolerance as the A7 DAC
changes the gain of the IF calibration amplifier on the A9 third
converter assembly. Figure
Figure 9-2, Figure 9-3, or
for more information.
Check the signal amplitude along the signal path from the RF input,
through the IF section, to the output of the A14 log amplifier. Refer to
"Isolating an RF, LO, IF, or Video Problem"
troubleshooting information.
Cal harmonic >= 5.7 GHz NOT found (U)(H)
Indicates that the CAL YTF routine for an 8595E cannot find a
harmonic of the 300 MHz calibration signal.
Related Assemblies
A9 third converter.
Troubleshooting Hints
Ensure that the CAL OUT connector is connected to the analyzer input,
perform the CAL FREQ &AMPTD routine, and then perform the CAL
YTF routine again.
Chapter 14
routine, the amplitude of the video signal at the
9-1, IF/Control Overall Block Diagram, and
Figure 9-4, RF Section Overall Block Diagram
in
Analyzer Messages
Interpreting Analyzer Messages
Chapter 4 for further
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