Tektronix 543B, Instruction Manual

Page: 27 / 90

SECTION 5
CALIBRATION
Introduction
The Type 543B Oscilloscope is a stable instrument which
will provide many hours of trouble-free operation. How­
ever, to ensure measurement accuracy, it is suggested that
you recalibrate the instrument after each 500 hours of
operation or every six months if used intermittently. It
will also be necessary to recalibrate certain sections of the
instrument when tubes, transistors, or other components
are replaced.
In the instructions that follow, the steps are arranged in
the proper sequence for full calibration. Each numbered step
contains the information necessary to make one adjustment.
If a complete calibration is not neceessary, you may perform
individual steps, provided that the steps performed do not
affect other adjustments. It is most important that you are
fully aware of the interaction of adjustments. Generally
speaking, the interaction of controls will be apparent in the
schematic diagram. If you are in doubt, check the calibra­
tion of the entire section on which you are working.
If you make any adjustments on the power supplies, you
will have to check the calibration of the entire instrument.
In particular the sweep rates and vertical deflection factors
must be checked.
Equipment Required
The following equipment is necessary for a complete cali­
bration of the Type 543B Oscilloscope.
1. A Dc voltmeter having a sensitivity of at least 5000 Ω/
volt and calibrated for an accuracy of at least 1 % at
100, 150, 225, 350 and 500 volts, and for an accuracy of
at least 3% at 1700 volts. Portable multimeters should
be regularly checked against an accurate standard and
corrected readings noted, where necessary, at the above
listed voltages.
2. An accurate rms-reading ac voltmeter, having a range
of 0-150 volts. (0-250 or 0-300 for 230-volt operation).
3. Variable auto-transformer having a rating of at least
6.25 amperes.
4. Time-Mark Generator, Tektronix Type 180A or equiv­
alent, having markers at 1 ,usec, 10 μsec, 50 μsec,
100 μsec, 1 msec, 5 msec, 10 msec, 100 msec, 1 sec, and
5 sec and sinewave outputs of 10 mc and 50 mc, all
having an accuracy of at least 1%
5. Test load unit, Tektronix Type TU-7. Contains a pulse
generator capable of producing pulses with a risetime
of 3 nsec or faster. This multi-purpose test-load unit
is the only plug-in needed to perform a complete cali­
bration of the oscilloscope.
6. Low-Bandwidth Test Oscilloscope with a 1 X attenuator
probe. Bandwidth of dc to 350 kc or better.
7. Two coaxial cables, 50-ohm nominal impedance, 42"
long with BNC plug-connectors on each end. Tektronix
Part No. 012-057.
8. Adapter, single binding post fitted with a BNC plug.
Tektronix Part No. 103-033.
9. Coaxial connector adopter with BNC-jack and UHF-plug
connector fittings. Tektronix Part No. 103-015.
10. Jumper clip lead, about 4" long. Equipped with minia­
ture alligator clips on each end.
11. Two interconnecting leads, 18" long, with combination
plug-and-jack banana-type connectors on each end.
Tektronix Part No. 012-031.
12. BNC T connector. Fits one BNC jack and accepts two
BNC plugs. Tektronix Part No. 103-332.
13. Miscellaneous Items
1-Screwdriver, 3 /16" wide bit, shank about 3" long.
1-Screwdriver, 3/32 " wide bit, shank about 2" long.
1-Jaco No. 125 insulated low-capacitance-type screw­
driver with a 1½ " long shank and ½" wide metal
tip. Total length is 5". Tektronix Part No. 003-000.
1-Low-capacitance alignment tool consisting of a handle
(Tektronix Part No. 003-007), a gray nylon insert with
a metal screwdriver tip (Tektronix Part No. 003-334),
a 5/64 hexagonal wrench insert (Tektronix Part No.
003-310).
1-Hexagonal wrench, ’ /16". For repositioning, if neces­
sary, the TRIGGERING LEVEL control knob.
PRELIMINARY PROCEDURE
Remove the cover(s) from the instrument to be calibrated.
controls as follows:
Crt Controls
0
As is
As is
Set the front-panel
INTENSITY
FOCUS
ASTIGMATISM
SCALE ILLUM
Time
TRIGGERING LEVEL
STABILITY
TRIGGERING MODE
TRIGGER SLOPE
VARIABLE (TIME/CM)
TIME/CM
HORIZONTAL DISPLAY
SINGLE SWEEP
5
Base
Fully clockwise
Fully clockwise
AC
+ INT
CALIBRATED
.5 mSEC
NORMAL (X1)
NORMAL SWEEP
5-1