Tektronix 516 series, Instruction Manual

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We recommend that the Type 516 Oscilloscope be cali­
brated after each 500 hours of operation or every six months,
whichever comes sooner. It should not require more frequent
calibration. However, whenever tubes or other circuit com­
ponents are replaced, the calibration of the circuit involved
should be checked and, if necessary, readjusted.
Also, apparent troubles in the instrument can be caused by
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. If a
trouble occurs in the instrument, you should be sure that it is
not due to improper calibration before proceeding with more
detailed troubleshooting.
In the instructions that follow, the steps are arranged in
the proper sequence for a complete calibration of the instru­
ment. However, any single step may be performed individu­
ally or out of order as long as the entire step is performed,
including references to other steps or adjustments, with certain
exceptions. Due to interaction between adjustments in the
Horizontal and Vertical Amplifiers and the sweep timing cir­
cuits of the Time-Base Generator, single adjustments in these
circuits cannot be made. When amplifier adjustments are re­
required, the entire amplifier should be recalibrated. In ad­
dition, if the —150-volt Power Supply is adjusted, the entire
instrument should be recalibrated. Front-panel controls not
mentioned in a given step are assumed to be set at the po­
sitions they were in at the end of the previous step.
Figs. 6-1, 6-2, and 6-3 show the location of the internal
adjustments referred to in the Calibration procedures.
C A L I B R A T I O N
10/isec, 100 /isec, 1 msec, 5 msec, 10 msec, 100 msec, 1 sec,
and a sine-wave output of 20 megahertz; accuracy of at
least 1%.
5. Square-Wave Generator, Tektronix Type 106 or equiv­
alent. Required specifications are: (1) Output frequencies of
1 kHz and 450 kHz, (2) risetime of 15 nanoseconds or less,
and (3) output amplitude variable from approximately 40
millivolts to 100 volts.
6. Constant-Amplitude Sigal Generator, Tektronix Type
191 or equivalent. Required specifications are: (1) output
amplitude 200 millivolts and equal at all frequency settings,
and (2) output frequency variable from 1 MHz to over
15 MHz.
7. 52-ohm termination resistor, Tektronix Type B52-R or
equivalent.
8. 52-ohm 10-1 "L" pad, Tektronix Type B52-L10 or equiv­
alent.
9. Coaxial cable suitable for applying the outputs of the
square-wave generator and the time-mark generator to the
inputs of the Type 516, Tektronix Type P52 Coaxial Cable or
equivalent.
10. 20 pF Input Capacitance Normalizer, Tektronix Cali­
bration Fixture 067-0538-00.
11. Low-capacitance calibration tools: Tektror'x Part Nu n-
bers 003-0000-00, 003-0301-00 and 003-0007-00 or equiv­
alent.
CALIBRATION PROCEDURE
EQUIPMENT REQUIRED
The following equipment is necessary for a complete cali­
bration of the Type 516 Oscilloscope:
1. DC voltmeter (sensitivity of at least 5000Q/volt calibrat­
ed for an accuracy of 1% or better at 100 volts, 150 volts,
and 300 volts, and for an accuracy of 3% or better at 1675
volts.
2. Accurate rms-reading ac voltmeter, having a range of
at least 0-125 volts (0-250 volts for 234-volt instruments).
3. Variable autotransformer having a rating of at least
3 amperes at 125 volts (or 1.5 amperes at 250 volts for 234-
volt instruments).
4. Time-Mark Generator, Tektronix Type 184 or equivalent.
Time-Mark Generator used must have markers at 1 /xsec.
Preliminary
Remove the side covers from the Type 516 Oscilloscope.
Set the front panel controls as follows (controls not listed
may be left in any position):
TIME BASE
TRIGGER SELECTOR +INT.
(black)
TRIGGER SELECTOR AC
(red)
STABILITY fully counterclockwise but not PRESET
TRIGGERING LEVEL 0
HORIZ DISPLAY NORM.
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6-1