Tektronix 543B, Instruction Manual

Page: 34 / 90

Calibration — Type 543B/RM543B
•The adjustment of C368 and C387, C388, C394 interact and must be repeated several
times to obtain final adjustments.
TIME/CM
Switch
Setting
HORIZONTAL
DISPLAY
(SWEEP
MAGNIFIER)
Switch Setting
Time
Markers Adjustments Observe
10 μ SEC NORMAL (X1) 10 μsec C160E for best 10,
20 and 50 μsec tim­
ing.
1 marker/cm
5 μ SEC NORMAL (X1) 5 μsec C160C for best 1, 2
end 5 μsec timing.
1 marker/cm
2 μ SEC X100 50 mc *C387, C388, C394 1 cycle/cm
5 μ SEC X100 10 mc * C368 1 cycle/2 cm
.5 μ SEC NORMAL (X1 )
10 mc
C160A for best 0.5
and 0.2 μsec timing.
5 cycles /cm
.1 μ SEC NORMAL (X1)
10 mc
C361A 1 cycle/cm
.1 μ SEC
X2
50 mc **C361C 5 cycles/2 cm
.1 μSEC
X5
50 mc † C361E 1 cycle/cm
.2 μ SEC X10 50 mc †C361G 1 cycle/cm
.5 μ SEC X20 50 mc † C361J 5 cycles/4 cm
•’Adjustment is made disregarding the first centimeter of sweep.
'■’Disregard the first 3 cm of sweep when making these adjustments.
21. Set Lockout Level Adjust
Set the HORIZONTAL DISPLAY switch at NORMAL (XI)
the STABILITY control fully counterclockwise but not to
PRESET, and the A TIME/CM switch at .1 mSEC. Connect a
voltmeter to the cathode, pin 7, of V125 and adjust the
STABILITY control to a point just before the sweep free
runs; observe the voltmeter reading at this setting. Set the
SINGLE SWEEP switch to SINGLE SWEEP (center position)
and trigger the sweep by turning the STABILITY control
fully clockwise; the READY light should extinguish indicating
the sweep is now locked out. Then adjust LOCKOUT LEVEL
ADJ R125 for a voltmeter reading If volts below (less nega­
tive) the previous reading.
Return the SINGLE SWEEP switch to the NORMAL SWEEP
position. Connect a test lead between the CAL OUT con­
nector and the vertical input connecter. Set the AMPLITUDE
CALIBRATOR for a 2-volt output and adjust the triggering
controls and the Variable control of the TU-7 to obtain a
stable one-centimeter-high display. Remove the lead from
the vertical input connector, depress the SINGLE SWEEP
switch to RESET and let it return to SINGLE SWEEP (center
position); the READY light should ignite indicating the sweep
circuit is armed. Touch the test lead to the vertical input
connector to produce one sweep; the READY light should
extinguish upon completion of the sweep. Then turn the
STABILITY control fully counterclockwise but not to PRESET;
the READY light should not ignite and the sweep should not
run. Return the SINGLE SWEEP switch to NORMAL SWEEP.
22. Adjust Externa! Horizontal Amplifier Dc Balance
Connect a jumper from the SAWTOOTH OUT to the Ext
Input connector, set the Type TU-7 Test Function switch to
Gain Set, the HORIZONTAL DISPLAY to EXT and turn the
STABILITY control fully clockwise. Use the HORIZONTAL
POSITION control to position the vertical trace to the left
vertical graticule line. Now, adjust the EXT HORIZ DC BAL
(see Fig. 5-3) control for no horizontal shift of the trace
while turning the horizontal VARIABLE front-panel control.
23. External Horizontal Amplifier Input Gain
With conditions as in step 22, connect a jumper from
CAL OUT to EXTERNAL HORIZ IN, set AMPLITUDE CALI­
BRATOR to .5 VOLTS, EXTERNAL HORIZONTAL VOLTS/CM
to .1 and turn VARIABLE control to CALIBRATED. Adjust
EXT HORIZ AMP CAL R361M (see Fig. 5-2) until 5 cm of
horizontal deflection arc observed between the two verti-
cal lines. Set the AMPLITUDE CALIBRATOR control to 5
VOLTS and the EXTERNAL HORIZONTAL VOLTS/CM to 1.
Check for 5 cm of horizontal deflection between the vertical
lines. Switch EXTERNAL HORIZONTAL VOLTS/CM to 10
and the A.MPLITUDE CALIBRATOR to 50. Horizontal deflec­
tion should be 5 cm. (Attenuator accuracy — 3%.)
24. Adjust External Horizontal Attenuator Compensa ­
tion
Connect a jumper from SAWTOOTH OUT to the vertical
input. Feed 5 VOLTS from CAL OUT to both EXTERNAL
HORIZ IN and TRIGGER INPUT connectors. Set the controls
as follows.
EXTERNAL HORIZONTAL
VOLTS/CM
TRIGGER SLOPE
TIME/CM
VARIABLE (Plug-In)
1
-EXT
1 mSEC
Adjust to display 2 cycles
of square wave vertically.
5-8
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