SECTION 6
CALIBRATION
Type 503
Introduction
The Type 503 Oscilloscope is a stable instrument and
should not require frequent calibration. However, it will
be necessary to calibrate certain parts of the instrument
when tubes or components are changed. Also, a periodic
calibration is desirable from the standpoint of preventive
maintenance.
Apparent trouble in the instrument may be due to improper
calibration of one or more circuits. Consequently this sec
tion of the manual should be used in conjunction with the
Maintenance section during troubleshooting work. If trouble
occurs in the instrument, be sure that it is not due to improper
calibration before proceeding with more detailed trouble-
shooting.
In the instructions that follow, the steps are arranged in
the proper sequence for a complete calibration of the instru
ment. Each numbered step contains the information required
to make one adjustment or a series of related adjustments.
Controls not mentioned in a given step are assumed to be
set at the positions they were left in during the preceding
step.
If a single control requires adjustment, and the particular
control is known, it can often be adjusted without calibrating
the entire instrument, provided the control does not interact
with other adjustments. In such cases, the control is adjusted
in the normal manner, as described in the applicable cali
bration step. It may be necessary, however, to refer to the
calibration steps immediately preceding the adjustment
desired to determine the proper setting for the controls not
mentioned in that step. Due to the interaction beween adjust
ments in the horizontal and vertical amplifiers, single adjust
ments in these circuits usually cannot be made. When ampli
fier adjustments are required, the entire amplifier should
be calibrated. In addition, if the -100-volt supply is adjust
ed, the entire instrument must be calibrated.
RECOMMENDED EQUIPMENT
General
The following list of equipment, or its equivalent, is recom
mended for complete calibration of the Type 503. Specifi
cations given are the minimum necessary for accurate cali
bration of this instrument. All test equipment is assumed to
be correctly calibrated and operating within the original
specifications. If equipment is substituted, it must meet or
exceed the specifications of the original equipment.
Special Test Equipment
For the quickest and most accurate calibration, special
calibration fixtures are used where necessary. All cali
bration fixtures listed under Recommended Equipment can
be obtained from Tektronix, Inc. Order by part number
through your local Tektronix Field Office or representative.
1. Test Oscilloscope. Minimum vertical deflection factor,
1 mV/div; bandwidth, DC to 450 kHz. Tektronix Type 503
recommended.
2. DC voltmeter. Calibrated to 1 % accuracy at 12.6, 85,
100 and 250 volts DC, within 3% accuracy at 3000 volts
DC. For example, Simpson Model 260-5P, or Triplett Model
630PLK.
3. Variable autotransformer. Range, 105 VAC to 125
VAC to at least 150 volts-amperes; with RMS meter.
4. Square-wave generator. Range, 0.5 volts to 20 volts
at 1 kHz; risetime, 120 nanoseconds or faster. Tektronix Type
106 recommended.
5. Constant-amplitude sine-wave generator. Signal fre
quencies, 50 kHz, 350 kHz, and 450 kHz; output 0 to 5 volts
Tektronix Type 191 recommended.
6. Standard Amplitude Calibrator. Accuracy, 0.25%; out
put, 5 mV to 100 volt square waves. Tektronix Calibration
Fixture Part No. 067-0502-00 recommended.
7. Time-mark generator. To provide markers from 1 /xs
through 5 seconds; accuracy, 0.2% or better. Tektronix Type
184 recommended.
8. 10X probe. Tektronix Type P6006, Part No. 010-0125-00
recommended.
9. 1 X probe with UHF connector. Tektronix Type P6027,
Part No. 010-0070-00 recommended.
10. Input time-constant normalizer, 47 pF, with UHF con
nectors. Tektronix Part No. 011-0068-00.
11. 50 Q termination with UHF connectors, Tektronix Part
No. 011-0045-00.
12. 50 Q cables with UHF connectors. Tektronix Part No.
012-0001-00 (2 required).
13. Adapter, UHF T, Tektronix Part No. 103-0026-00.
14. Adapter, GR to UHF female. Tektronix Part No. 017-
0022- 00.
15. Adapter, UHF quick-connect. Tektronix Part No. 003-
0028-00 (2 required).
16. Adapter, male BNC and female UHF. Tektronix Part
No. 103-0032-00.
17. Attenuator, 10:1 with UHF connectors. Tektronix Part
No. 011-0031-00.
18. Insulated alignment screwdriver. Tektronix Part No.
003-0000-00.
19. Insulated alignment tool. Tektronix Part No. 003-
0003-00.
6-1