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Calibration
Procedure
—
Type
502A
19.
.2MV/CM
GAIN
Apply a
.5
millivolt signal
from the calibrator
to input
A
of
the vertical amplifier. Place the SENSITIVITY switch in
the .2
mVOLTS PER
CM position. Set
the
.2MV/CM GAIN
control
for 2.5 centimeters of vertical deflection. Repeat
steps 18
and 19 until both adjustments are correct.
Both
of
the above
gain
adjustments should also be checked
in
the B-DC position
of the
Input Selector switch. At this time
the
other
positions of the SENSITIVITY switch should
be
checked for proper attenuation. Disconnect
jumpers.
20.
Adjusting
R429, VAR DC BAL
Set
the SENSITIVITY switch
to .2 VOLTS PER CM and the
TRIGGERING
LEVEL
to RECURRENT. With the vertical
POSITION Control, position
the
trace to the appropriate
graticule
center line.
While
rotating the VARIABLE SENSITIVITY Control through
its
range,
adjust R429 until the trace no longer moves as
the VARIABLE
SENSITIVITY Control
is rotated. The trace
should
now
show no
movement when it is sitting on the
appropriate
graticule center line and the VARIABLE SENSI
TIVITY
Control is
rotated.
Refer to figure
5-15 or 5-17 for
the
location of R429.
21.
Vertical DC Shift
Turn
the Input
Selector to A-DC and the SENSITIVITY
switch to
.2 VOLTS PER CM. Now vertically deflect the trace
with
enough
dc voltage to
move
it about 8 cm. A V.O.M.
is
a
convenient source of voltage.
After
deflecting the trace observe the
drift, if any. The
drift
should
not be more than about 1
mm.
22.
High
Frequency Compensations
Reset
the following
controls.
Input Selector
B-DC
SENSITIVITY
.2
VOLTS
PER
CM
TIME/CM
50 μSEC
From a Type
105 apply 10 kc square-waves to the B input
of
the vertical. The cable should have a 50Ω termination
connected
at each end.
Adjust the oscilloscope for
a stable
display.
Adjust
the
amplitude of the Type 105 until a dis
play
of
3 cm is observed on the screen. The bottom of the
square
wave should rest on the graticule center line for the
amplifier
you
are calibrating.
Now
adjust C470, C480 and
C478
for the best possible
square-wave
bottom. After
adjusting for a square bottom
reset
the Input Selector to A-DC and connect the cable and
termination to the A input.
Line up the
top of the square
wave
with the proper graticule center line and adjust C469.
C469
is adjusted for an optimum square
top on the square
wave.
It will be necessary to
recheck the adjustment
of C470,
C480,
C478 and C469 as the adjustment of one of these
capacitors
may
affect the adjustment of the others.
R462
C469
Fig.
5-9.
Location of C469
and R462 in Vertical Amplifier.
23.
Adjusting
Common Mode
Rejection Ratio
From the
sine-wave generator, whose
qualifications are
described
in
the Equipment Required list, apply 1 volt of
200kc
sine-wave. The
waveform will
be
applied to both
the A and
B inputs of the
vertical amplifier.
Also apply
the waveform
to the horizontal amplifier EXTERNAL con
nector.
The
one volt of signal may be measured by setting the
Input
Selector
switch in
A-DC and the
SENSITIVITY switch
to .2
VOLTS
PER CM. The cable which leads from the gen
erator
to the oscilloscope should be terminated
at both
ends
with 50Ω terminations. With the properly terminated
cable connected
to the
oscilloscope adjust the output ampli
tude
of the sine-wave generator until a deflection of
5cm
is
obtained on the crt.
Set
the
Input
Selector switch
to A-B (DIFF)-DC, the
vertical
SENSITIVITY
switch to
1 mVOLT PER CM and
the HORIZON
TAL
DISPLAY switch to .1 EXT
VOLT/CM. A lissajous wave
form
should now
be displayed.
While observing this wave
form
adjust
the lead dress of the covered lead running
from
the end
of R462 (5meg) to pin 5
of V414 for minimum
opening
of
the loop.
Elimination
of the eye of the loop, a straight line would
result
in
a
rejection ratio
of 10,000 to 1. The opening of the
loop
must
be less than 2
cm to give an acceptable rejection
ratio.
To
check the adjustment change the generator frequency
to 100
kc.
Now change the SENSITIVITY switch to .2 mVOLTS
PER
CM
and check to see that the opening in the loop does
not exceed
5cm.
It should be noted
that
there may be some interaction
between
the High Frequency Compensations and the Com
mon
Mode
Rejection Ratio. Disconnect the input signal and
all
cables
to oscilloscope.
NOTE
At
this time the vertical
which has not been cali
brated
up to now must
be done, up to this point,
before
proceeding with the calibration procedure.
5-7
Содержание 502A
Страница 4: ......
Страница 22: ...Circuit Description Type 502A Fig 3 2 Simplified Sweep Trigger Circuit t i CO ...
Страница 27: ...Circuit Description Type 502A Fig 3 4 Simplified Horizontal Amplifier 3 9 ...
Страница 30: ...Circuit Description Type 502A 3 12 NORMALLY CLOSED LOCATED ON REAR PANEL Fig 3 6 Simplified CRT Circuit ...
Страница 32: ...Circuit Description Type 5O2A Fig 3 7 Simplified Calibrator Circuit 3 14 ...
Страница 34: ...NOTES ...
Страница 56: ...NOTES ...
Страница 60: ...Parts List Type 502A LEFT SIDE 6 4 ...
Страница 64: ...Parts List Type 502A RIGHT SIDE 6 8 ...
Страница 67: ...Parts List Type 502A TOP 6 11 ...
Страница 70: ...Parts List Type 502A BOTTOM 6 14 ...
Страница 73: ...Parts List Type 502A REAR 6 17 ...
Страница 89: ...TYPE 502A OSCILLOSCOPE A ...
Страница 90: ...A BLOCK DIAGRAM MRH Z6 3 ...
Страница 91: ... TYPE 502A OSCILLOSCOPE A ...
Страница 92: ...A CIRCUIT NUMBERS 1 THRU 59 I Ixj 263 TIME BASE TR IGGER ...
Страница 93: ......
Страница 95: ...TI M I NG RESI 5TORS TIMING CAPACITORS TYPE 502A OSCILLOSCOPE ...
Страница 96: ...SWI6O HOLD OFF CAPACITORS 4 RESISTORS TIM ING CAPACITORS o A TIMING SWITCH job ...
Страница 98: ... 1 INPUT AMPLIFIER OUTPUT AMPLIFIER A CIR CUIT NUMSER 5 300 THR U 399 ZG3 joe ...
Страница 100: ...CMO 363 VERTICAL ATTENUATOR SWITCH A ...
Страница 103: ...TYPE 5O2A OSCILLOSCOPE OOM HEATER WIRING DIAGRAM ...
Страница 104: ...POWER SUPPLY CIRCUIT NUMBERSI 600 THRU 799 ...
Страница 106: ...CIR CUIT NUMBER S 800 THR U 869 CRT CIRCUIT c 9G4 ...
Страница 107: ...CA LIBp A TOp MULTIVIBP A TOR 1 IOOV o TYPE 5O2A OSCILLOSCOPE A ...
Страница 108: ...CAL OUT CF CALIBRATOR A CIRCUIT NUMBERS 8 7O THRU 899 4Z ...
Страница 110: ...TYPE 502A TENT S N 23430 PARTS LIST CORRECTION CHANGE TO V152 157 0104 01 Selected 6AL5 M913U 665 ...