Set Int. Tbig. Dc Level Control; Adjust Trigger Level Centering; Adjust Trigger Sens.; Adjust Preset Stability - Tektronix 545 Calibration Procedure

15. (oont.)
Now repeat the last step only this time put the probe on the grid end of the
1 meg resistor from the center arm of the DELAYING SWEEP TRIGGERING LEVEL con­
trol and set the knob for zero volts.
convenience and has nothing to do with MAIN SWEEP triggering.)
16
.

SET INT. TBIG. DC LEVEL CONTROL

Position the trace of the scope under calibration to the center of the graticule.
Re-check the test scope zero reference and connect the probe to R8, k'JQ to pin 7
of V8. This point should be at zero volts.
tion from +INT to -INT and adjust INT. TRIG. DC LEVEL ADJ. for zero volts as in­
dicated on the test scope.
17.

ADJUST TRIGGER LEVEL CENTERING

Set TRIGGERING MODE switch to AC SLOW and TRIGGER SLOPE switch to +LINE.
test scope VOLTS/CM switch to 0.2 VOLTS/CM. AC.
on scope under calibration, and adjust TRIGGERING LEVEL CENTERING so that the
waveform on the test scope is symmetrical.
MAGNIFIER. ON and horizontally center switching portion of the multi waveform. Now
switch the TRIGGER SLOPE switch, of the scope under calibration, back and forth
from +LINE to -LINE and at the same time re-adjust TRIGGERING LEVEL CENTERING until
there is no horizontal shifting of the switching portion of the multi waveform.
18. ADJUST TIRGGER SENS.
Turn the TRIG. SENS. pot to the right (cw) until oscillation occurs at the leading
and trailing edges of the multi waveform.
STEP 16.) Note the amplitude of the spike on the waveform just at the point of os­
cillation. Now turn the TRIG. SENS, left (ccw) until this qpike is slightly less
than one-half (0.5) of the original size.
19.

ADJUST PRESET STABILITY

Use 100 psec/cm.
BILITY control clockwise until the sweep triggers.
should read about 80 v on a meter.
the sweep free-runs (trace will brighten), the center arm on the control should
be between 15 v and 25 v higher.
way between the two readings obtained.
20.

CHECK TRIGGER CIRCUIT FOR PROPER OPERATION

Obtain 2 mm of vertical deflection from the calibrator and see that the trigger
circuit will work properly in all positions, except LINE and HF SYNC, of the TRIG­
GER SLOPE and TRIGGERING MODE switches.
21.

ADJUST DELAY LINE AND HF COMPENSATIONS

With the VOLTS/CM switch at 0.05. variahle VOLTS/CM control full right (cw), insert
into the K UNIT from a properly terminated fast rise-time square-wave generator, a
kOO kc signal of about two or three cm of vertical deflection.
can also be used.
mers in the delay line with an insulated tool for optimum square-wave response. The
variable coils control the amount of spike on the leading edge of the waveform.
22.

MEASURE VERTICAL RESPONSE

Measure the bandwidth with a constant amplitude sine-wave generator, for example,
Tektronix Type 190.
September, 1959
Turn TRIGGERING MODE to AUTOMATIC. +LINE. Turn the PRESET STA­
Now continue turning PRESET STABILITY until
Turn the control back until the meter reads half
Switch the MAIN SWEEP TIME/CM to 1 pSEC, X5. Adjust the trim­
Turn the generator to 2 me and insert enough signal for 5 cm
(This setting is done at this time for
Now switch the scope under calibra­
Connect probe to pin 6 of V20,
For final adjustment switch test scope
(Test scope probe should still be as in
The center arm of the control
Switch
A Type 53/5^ F UNIT
5^5 - 3