Tektronix 507, Инструкция по эксплуатации

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ADJUSTMENT
1. Power Supply Unit
—250 VOLTS: Connect voltmeter to pin 8 of
power plug on underside of power unit or on
underside of indicator unit. Adjust R625 labeled
—250 V ADJ. as accurately as possible.
NOTE: Be sure your meter is accurate; many
portable voltmeters are in error by as much as
three percent.
2. Cathode-Ray Tube Voltage Supply
- 4 KV: Turn INTENSITY control full counter­
clockwise. Connect 20,000-Q/v voltmeter to un­
grounded end of C841 (the junction of C841,
C840 and R840, located in the vicinity of the four
high-voltage neon glow lamps, near the panel
supporting the —4 KV ADJ., GEOM. ADJ. and
MAX. INTENSITY controls). Make sure your volt­
meter is set for negative polarity and to the
proper scale. Adjust R814 labeled —4 KV ADJ.
as accurately as possible.
3. Cathode-Ray Tube Intensity
Maximum intensity is adjusted by means of
R851 labeled MAX. INTENSITY. Turn STABILITY
control full counterclockwise and INTENSITY con­
trol full clockwise; adjust R851 until a spot just
appears on the screen.
4. Cathode-Ray Tube Unblanking
Set the MICROSECONDS/CM control to 10,
turn STABILITY control full counterclockwise, and
connect a 20,000-0/v voltmeter across R154, the
plate-load resistor for V I44 and V I54. R154 is
the large 25-watt resistor located near the panel
that supports the DUTY CYCLE LIMITED and UN­
BLANKING controls. Adjust R146, labeled UN­
BLANKING, for 100-volt drop across R154. The
UNBLANKING adjustment controls the screen
voltage of V I44 and V I54 to adjust their plate
current.
Remove the voltmeter leads from R154, set the
MICROSECONDS/CM control to 2 and turn the
STABILITY control full clockwise. Connect the
probe from another oscilloscope to the cathode
of V I53, and adjust LI 54 (next to R154) for maxi­
mum overshoot at the leading edge of the posi­
tive pulses displayed; this w ill occur when LI54
is adjusted for maximum inductance.
5. Cathode-Ray Tube Geometry Adjust
The operating voltages required for best
linearity at the extremes of deflection may vary
somewhat between cathode-ray tubes. The
GEOM. ADJ. control R861 accommodates this
variation.
Free run the sweep by turning the STABILITY
control full clockwise, and position the trace
to the top line of the graticule. Adjust the
GEOM. ADJ. control for best linearity. Position
trace at bottom of graticule and check linearity;
a compromise setting of the GEOM. ADJ. con­
trol may be necessary for best overall linearity.
6. Sweep Duty Cycle Limit
Set the MICROSECONDS/CM switch to 2 and
free run the sweep by turning the STABILITY con­
trol full clockwise; set the SIGNAL MODE switch
to EXTERNAL NORMAL. Connect the probe from
another oscilloscope to the cathode of V I33, and
adjust the test oscilloscope for a sweep speed of
50/xsec/division. Adjust the DUTY CYCLE LIMIT­
ED control R137 so that the duration between
pulses, on the crt of the test oscilloscope, is
about ten times the pulse duration. Jitter in the
right hand pulse displayed on the test oscillo­
scope is normal, since the sweep is free running
rather than triggered.
Set the MICROSECONDS/CM control on the
Type 507 to .05, and adjust the sweep speed of
the test oscilloscope so that the positive pulse
of the displayed square wave is approximately
10 centimeters (or divisions) in length. At this
fast sweep rate the rise and fall of the positive
pulse will be spread out considerably; make the
10-centimeter (or divisions) measurement from
the start of the rise to the start of the fall. Then
turn the MICROSECONDS/CM switch to .02
and adjust C112L, located on the MICROSEC­
ONDS/CM switch, for a 9-centimeter (or div­
ision) length of the positive pulse.
7. Time-Mark Generator
Before adjusting the timing of the markers or
the sweep circuit (next step), be sure the power
supply voltages are correct. Also make sure the
the instrument is thoroughly warmed up; heaters
should be on thirty minutes and plate voltage
should be on for five minutes before any adjust­
ments are made.
ADJUSTMENT PROCEDURE — TYPE 5 0 7
4-1