Agilent Technologies 8590 Series Service Manual page 586

Softkey Descriptions
Softkey Descriptions
The 10 dB attenuator step is the amplitude
reference used by the
routine while calibrating the input attenuator. Refer
to the
information about the calibration of the input
attenuators.
Refer to "To check control of the A3 input
attenuator" in
that are in use for a given input attenuation setting.
• SGAIN. The step-gain and linear-gain corrections
are mathematical offsets of the digitized video signal
on the A16 processor/video assembly. The first six
entries in the "SGAIN" column are for the 10 dB step
gains on the A12 amplitude control assembly. The
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step gain as an amplitude reference while
calibrating the step gains.
The last four entries in the "SGAIN" column are for
the 10 dB linear gains on the A14 Log Amplifier
assembly.
Refer to the
information about the calibration of the step-gain
and linear-gain stages. Refer to
the gain stages that are in use for a given
reference-level setting.
• GAIN. The reference-level-vernier error corrections
are DAC values that calibrate the reference level at
top-screen during the
routine.
The first five entries are fixed constants. The second
five entries provide a coarse gain-adjustment of the
A9 Third Converter assembly. Only one DAC value
is produced by the calibration routine and is
duplicated for all five entries. The A7 analog
interface assembly uses the DAC value to adjust the
gain of the A9 assembly. The DAC adjustment range
is from 0 to 255. The higher the DAC value, the
greater the gain on the A9 assembly. Refer to the
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information.
• ERR. The ERR column, next to GAIN, is the video
offset "fine tuning" of the reference level calibration.
586
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softkey description for more
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Chapter 6 to identify the attenuators
self-calibration routine uses the 10 dB
softkey description for more
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softkey description for more
self-calibration
Chapter 5 to identify
self-calibration
Chapter 13