SECTION 5
CALIBRATION
PROCEDURE
General Information
The
instrument should not require frequent recalibration,
but
occasional adjustments will
be
necessary when tubes
and
other components
are changed. Also, a
periodic calibra
tion
is
desirable from the standpoint of preventive main
tenance.
Apparent
troubles
occurring
in the instrument are often
actually
the result of improper calibration of one or more
circuits.
Consequently
this section of the manual should be
used
in
conjunction with the Maintenance
section during
troubleshooting
work.
In the
instructions that follow, the steps are
arranged
in
the proper sequence
for a complete calibration of the
instrument. Each
numbered
step contains the information
required
to
make
one adjustment or a series of related
adjustments.
In each calibration
step
only the required information is
given.
Controls
are assumed to be set at the
positions
they
were in during the previous step unless specific
instructions
are
given to change their settings. All test
equipment,
except for input
signal sources, and all jumpers
are
disconnected at the end of each step unless instructions
are
given to the contrary. Input signal voltages
should
remain
connected to the instrument until
specific instruc
tions
are given to disconnect them or until another input
signal
is applied to the same input connector.
It
will be
necessary for you to refer to the calibration
steps
immediately preceding the adjustment you wish to
make
to
determine the proper settings for the controls not
mentioned
in that
step. Due to
the
interaction between
adjustments
in
the
horizontal and vertical
amplifiers, single
adjustments
in these
circuits usually
cannot be made. When
amplifier adjustments are
required, the entire amplifier
should
be calibrated.
In addition, if either
the
—150 volt
supply
or the high voltage power
supply is adjusted, the
entire
instrument
must be calibrated.
If
you find
that a circuit is out of calibration, but you
are
not aware of
which particular adjustment will correct
the
difficulty, it is usually best to calibrate the entire circuit.
Equipment Required
The
following equipment or its equivalent is necessary for
a
complete calibration
of
the Type 502A Oscilloscope.
1.
DC voltmeter (sensitivity of at least 5000 ohms per
volt)
with corrected
readings within 1% for 100, 150 and 350
volts
and
within 3% for 2900 volts. Be sure your meter is
accurate; few
portable test meters
have the required ac
curacy,
particularly
after a period of use.
Fig.
5-1. Tools required for calibrating the Type 502A Oscilloscope.
2.
Accurate
rms-reading ac
voltmeter, 0-150 volts (0-250
or
0-300 volts
for 210- to 250-volt operation).
3. Variable autotransformer,
having a rating of at least
500
watts.
4. Time-mark
generator, Tektronix Type 180A or 181. If
neither
of
these instruments is available, it will be necessary
to
substitute a time-mark generator having markers at 1
microsecond,
5 microsecond,
10 microsecond, 50 microsecond,
100
microsecond, and 1 millisecond intervals.
5.
Square-wave
generator, Tektronix
Type 105. If
a Type
105
Square-Wave Generator is not available, it
will be
necessary
to
substitute a
square-wave generator with the
following
specifications: (1)
output frequencies of 200 cycles,
1
kilocycle, and
10 kilocycles, (2)
rise-time no more than
20
nanoseconds, and (3) output amplitude
variable between
approximately
40 millivolts
and approximately
100 volts.
6.
Oscilloscope,
Tektronix Type 316 or
317. If a
Type 316
or
317
Oscilloscope is not available, it will be necessary to
substitute
an oscilloscope with the
following specifications:
(1) calibrated
vertical
deflection factors
from .01 to 10
volts
per division and (2) bandpass of dc to 10 megacycles.
7. 50-ohm,
42 inch Coaxial Cable
(1)
8.
Tektronix
50-ohm Termination Resistor. (2)
9.
Tektronix
Type 5XT, 50-ohm T-Pad.
(2)
10. Tektronix
47 pf Input Time Constant Standardizer,
Tektronix
part number 011-030 (1).
11. Tektronix
Type
10XT, 50-ohm T-Pad. (1)
12. Coaxial "T" Connector.
(1)
5-1
Summary of Contents for 502A
Page 4: ......
Page 22: ...Circuit Description Type 502A Fig 3 2 Simplified Sweep Trigger Circuit t i CO ...
Page 27: ...Circuit Description Type 502A Fig 3 4 Simplified Horizontal Amplifier 3 9 ...
Page 32: ...Circuit Description Type 5O2A Fig 3 7 Simplified Calibrator Circuit 3 14 ...
Page 34: ...NOTES ...
Page 56: ...NOTES ...
Page 60: ...Parts List Type 502A LEFT SIDE 6 4 ...
Page 64: ...Parts List Type 502A RIGHT SIDE 6 8 ...
Page 67: ...Parts List Type 502A TOP 6 11 ...
Page 70: ...Parts List Type 502A BOTTOM 6 14 ...
Page 73: ...Parts List Type 502A REAR 6 17 ...
Page 89: ...TYPE 502A OSCILLOSCOPE A ...
Page 90: ...A BLOCK DIAGRAM MRH Z6 3 ...
Page 91: ... TYPE 502A OSCILLOSCOPE A ...
Page 92: ...A CIRCUIT NUMBERS 1 THRU 59 I Ixj 263 TIME BASE TR IGGER ...
Page 93: ......
Page 95: ...TI M I NG RESI 5TORS TIMING CAPACITORS TYPE 502A OSCILLOSCOPE ...
Page 96: ...SWI6O HOLD OFF CAPACITORS 4 RESISTORS TIM ING CAPACITORS o A TIMING SWITCH job ...
Page 98: ... 1 INPUT AMPLIFIER OUTPUT AMPLIFIER A CIR CUIT NUMSER 5 300 THR U 399 ZG3 joe ...
Page 100: ...CMO 363 VERTICAL ATTENUATOR SWITCH A ...
Page 103: ...TYPE 5O2A OSCILLOSCOPE OOM HEATER WIRING DIAGRAM ...
Page 104: ...POWER SUPPLY CIRCUIT NUMBERSI 600 THRU 799 ...
Page 106: ...CIR CUIT NUMBER S 800 THR U 869 CRT CIRCUIT c 9G4 ...
Page 107: ...CA LIBp A TOp MULTIVIBP A TOR 1 IOOV o TYPE 5O2A OSCILLOSCOPE A ...
Page 108: ...CAL OUT CF CALIBRATOR A CIRCUIT NUMBERS 8 7O THRU 899 4Z ...