Tektronix 442, Инструкция по эксплуатации

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Calibration Procedure—442 Service
Performance Check
Test Equipment list is not available, first check the
Minimum Specifications column carefully to see if any
other equipment might suffice. Then check the Usage
column to see the purpose of this item. If used for a check
that is of little or no importance to your measurement
requirements, the item and corresponding steps can be
deleted.
Preparation
Connect the test equipment to an appropriate power
input source. Turn on and allow a 20-minute warmup
period before commencing the Performance Check.
Display
Performance Checks should be made with a stable,
well-focused, low-intensity, vertically centered (unless
otherwise stated) display. Unless otherwiseinstructed, set
the Intensity, Astigmatism, Focus, Trigger, and Position
controls as required.
PRELIMINARY PROCEDURE
Perform the following steps to place the 442
Oscilloscope into a basic operating mode before pro­
ceeding with the Performance Check steps.
W A R N I N G I
Make sure the 442 is unplugged from the power
input source before changing the line voltage set­
tings.
1. Use a small blade screwdriver to set the (120 V or
240 V) Line Voltage Selector and (HI or LO) Range
Selector switches (both are accessible through openings
in the bottom of the cabinet) to the correct settings for the
power input voltage source that will be used during this
procedure.
If the Line Voltage Selector (120 V/240 V) setting is
changed, the line fuse (located in.a fuse holder on
the rear panel) must be of the value specified for the
new Selector setting. Refer to the Operating Instruc­
tions section of this manual for complete operating
voltage and fuse information.
Unless otherwise specified, the 442 is originally set for
120 V and HI line operation.
2. Connect the 442 power cord plug tothe line voltage
source and press the ON/OFF button on (in). The POWER
ON LED should light.
NOTE
The 442 must have a warmup time of at least 20
minutes before starting the Performance Check
Procedure, and must have been adjusted at an
ambient temperature b20° C and +30° C to
ensure that checks in this procedure will meet
specifications listed in Section 1.
3. Set the TRIGGERING MODE to AUTO, and
SOURCE to CH 1/CH 2.
4. Set CPLG to AC (out) and leave it there throughout
the Performance Check procedure unless instructed
otherwise.
5. Set the following 442 controls as listed:
VERT MODE
CH 1
POSITION (CH 1 & CH 2)
Midrange
VOLTS/DIV (CH 1 & CH 2) 2m (IX)
VOLTS/DIV VAR (CH 1 & CH 2) Detent (fully cw)
AC-GND-DC (CH 1) GND
AC-GND-DC (CH 2) DC
SEC/DIV
,1m
MAGNIFIER
XI (out)
POSITION (horizontal) Midrange
SLOPE
+ (out)
HOLD OFF
Fully ccw
LEVEL
Fully cw
INTENSITY Midrange
FOCUS Midrange
6. A baseline trace should be visible within the
graticule area. Adjust the INTENSITY and FOCUS con­
trols for a low-intensity, well-defined trace.
NOTE
The ASTIG control also affects trace definition, and
if necessary, should be adjusted (after a signal has
been applied) for best overall definition of a dis­
played signal (use a small bit screwdriver for this
adjustment).
The baseline trace should be parallel with the horizon­
tal graticule lines. If it is not, adjust TRACE ROT (Trace
Rotation) with a small bit screwdriver until the trace is
aligned.
4-4
R E V A M A Y 1 9 8 0