Backing Up Analyzer Correction Constants - Agilent Technologies 8590 Series Service Manual

Backing Up Analyzer Correction Constants

This section describes how to retrieve the correction-constant data from
the instrument memory and record the data as a backup copy. As long
as the data remains valid, it can be used to recalibrate the instrument
quickly after a memory loss. It is recommended that a copy of this data
be maintained in the user's records. Procedures for restoring the
correction constants to battery-backed RAM memory are also provided
in this section.
Note that if the current correction constants are not valid, new
correction constants must be generated. Refer to the following
adjustment procedures in
• Adjusting the 10 MHz Reference.
• Adjusting the Frequency Response (for your analyzer).
• Adjusting the Cal Attenuator Error.
• Correcting the External ALC Error Correction (for Option 010 and
011 only).
The 8590 E-Series and L-Series spectrum analyzer, 8591C cable TV
analyzer, and 8594Q QAM analyzer stores the following correction
constants in RAM.
Flatness-correction constants. Used to correct
frequency-response amplitude errors.
Step-attenuation correction constants. Used to correct A12
Amplitude Control step-attenuator errors and provide a relative
amplitude reference for the CAL AMPTD self-calibration routine.
Timebase correction constant. Used by the DAC that tunes the
RTXO (10 MHz timebase) on the A25 Counter Lock assembly.
Analyzers equipped with the precision frequency reference do not use
this correction constant.
CALTGX slope and offset correction constants. Used to
improve the performance of the external automatic level control
(ALC). Only analyzers equipped with Option 010 or 011 use these
corrections.
Chapter 3
Backing Up and Reloading Correction Constants
Backing Up Analyzer Correction Constants
Chapter 2 of this service guide.
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