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Calibration—492/492P Service Vol. 1 (SN B030000 & up)
Performance Check
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PERFORMANCE CHECK PROCEDURE
INTRODUCTION
As stated in the section introduction, the following proce
dure is a functional as well as performance check. All perfor
mance requirements listed under electrical characteristics in
the Specification section are verified. The tests do not in
clude any internal adjustments or checks. The checks
should be performed in the sequence given because some
tests rely on the satisfactory performance of related circuits.
They are also arranged to minimize test equipment setup. If
a performance measurement is marginal or below specifica
tion, an adjustment procedure to optimize the circuit perfor
mance will be found under a similar heading in the
Adjustment Procedure of this section. If adjustment fails to
return the circuit to specified performance, refer to the Main
tenance section for troubleshooting and repair procedures.
After adjustment, return to the Performance Check to con
tinue with the calibration process.
INCOMING INSPECTION TEST
The Operators manual contains a functional check that
checks all functions of the 492/492P. This check is recom
mended for incoming inspections because it provides a reli
able indication that the instrument is performing properly.
This Performance Check procedure checks all instrument
specifications and requires sophisticated equipment as well
as technical expertise to perform.
b. Set the front-panel controls as follows:
BASELINE CLIP
Off
TRIGGERING
FREE RUN
TIME/DIV
AUTO
FREQUENCY RANGE
Band 1 (0—4.2 GHz,
FREQUENCY
0— 1.8 GHz
Option 01)
100 MHz
Vertical Display
10 dB/DIV
FREQ SPAN/DIV
100 kHz
AUTO RESOLUTION
On
RF LEVEL
-2 0 dBm
MIN RF ATTEN dB
0
MIN NOISE (push button)
Off (MIN DISTORTION)
FINE (push button)
Coarse (not illuminated)
Digital Storage (Option 02)
VIEW A
On
VIEW B
On
MAX HOLD
Off
SAVE A
Off
B-SAVE A
Off
PEAK/AVERAGE
Fully cw
c. Allow the instrument to warm up for at least two
hours before proceeding with this check.
VERIFICATION OF TOLERANCE VALUES
Compliance tests of specified limits, listed in the Perfor
mance Requirement column of the instrument specifica
tions, shall be performed after sufficient warm-up time and
preliminary preparation (such as front-panel adjustments).
Measurements shall be performed by instruments that do
not affect the values measured.
Measurement tolerance of test equipment should be neg
ligible in comparison to the specified tolerance; and, when
not negligible, the error of the measuring apparatus shall be
added to the tolerance specified.
PRELIMINARY PREPARATION
a.
Perform the initial calibration described under Turn On
Procedure in the Operator’s manual. For rackmount/
benchtop versions, refer to Rackmount/Benchtop section of
this manual.
1. C h e c k O p e ra tio n of F ro n t P a n e l P u s h B u tto n s
a n d C o n tro ls
The following procedure checks functions activated by
front-panel push buttons and that the buttons illuminate
when the function is active. Operation of the front-panel
controls is also checked.
With the CAL OUT signal applied to the RF INPUT, tune
the 100 MHz, —20 dBm signal to center screen. Reduce the
FREQ SPAN/DIV to 100 kHz keeping the signal centered on
screen with the FREQUENCY control. Press or change the
following push buttons and controls and note their effect.
INTENSITY. Rotate the control through its range and
note crt beam brightness change.
READOUT. Inactive state, no crt readout. Active state,
crt readout of REF LEVEL, FREQUENCY, FREQ
SPAN/DIV, VERT DISPLAY, RF ATTEN, FREQ RANGE,
and RESOLUTION BANDWIDTH. The INTENSITY control
changes brightness.
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REV AUG 1981
