Tektronix 535 Calibration Procedure Download

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c • Turn the HORIZCNTALPOSITION knob

until the left end of the display be

comes visible. Now turn the knob a short way

CCW

until the first f e w cycles,

which are obviously nonlinear, are positioned off the left end of the screen.

Check the trace for eight cycles of the sine wave over the middle

cm of the

graticule length. Within the middle

cm, there should be one cycle of the

sine wave for each centimeter of graticule length, within a tolerance of

±256.

Note: If it is not possible to obtain the results described for this opera

tion, and if parts and tubes in the sweep and sweep-amplifier cir

cuits are good and are properly connected, then the fault probably

lies in the way in which Steps 19 and 32 were carried out, so that

it is wise in case of difficulty to recheck these steps.

To check the horizontal gain.— Settings:

HORIZONTAL DISPLAY— EXT. SWEEP.

SLOPE (toggle)— +.

EXT. SWEEP ATTEN.—

CW,

ATTEN. (toggle)— XI.

5X MAGNIFIER— ON.

Feed 0.2 volt from the calibrator.to TRIGGER OR EXT. SWEEP PI. Position the

sweep on the screen with the HORIZONTAL POSITION control. Length of sweep

should be not less than

cm.

Now increase the calibrator output to 2 volts. Adjust EXT. SWEEP ATTEN. knob

for a horizontal deflection of 10 cm. Throw the ATTEN. toggle switch to the

X10 position, and turn the calibrator output to 20 volts. The new horizontal

deflection should be

minor division. This procedure checks the cor

rectness of the attenuation ratio of the X10 fixed attenuator.

35. To set DELAY START ADJ and DELAY STOP ADJ.

— Settings:

Main Sweep TRIGGERING LEVEL— CW or CCW.

Main Sweep STABILITY— CW.

TRIGGER SLOPE— +INT

Main Sweep TIME/CM— 10 p-sec.

MULTIPLIER— XI.

HORIZONTAL DISPLAY— DELAYING SWEEP.

gX MAGNIFIER— OFF.

Delaying Sweep TIME/CM— gOO psec.

LENGTH— CW.

SLOPE (toggle)— +.

ATTEN. (toggle)— XI.

a. Advance Delaying Sweep STABILITY to obtain trace. Adjust INTENSITY for

moderate brightness. Observe that a short brightened region (due to Main

Sweep unblanking) appears on trace. The brightened portion should move

along the trace when the DELAY-TIME MULTIPLIER is turned.

b. Connect VERT. SIG. OUT to TRIGGER OR EXT SWEEP IN. Display gOO-nsec

—

markers from Type !80. Adjust Delaying Sweep STABILITY and TRIGGERING

LEVEL for stable display. Align display with graticule, using HORIZONTAL

POSITION control.

c. Check the registration of the DELAY-TIME MULTIPLIER dial. Dial should

”

read 0,0 when the knob is rotated CCW until stop is reached.

August, 1956

FD-g35-l8

Summary of Contents for 535

Page 1: ...nces are specified it may be stated as a general guide that the resistance of the 1 0 volt supply usually runs in the neighborhood of I 000 to 5 000 ohms The resistances of the remaining supplies are progressively higher as you go to more positive voltages The 500 volt sup ply might be expected to have a resistance of about 50 000 ohms If any two sup plies appear to have the same resistance values...

Page 2: ...ly voltage falls outside these tolerances proceed as follows 1 Check that the supply affected is regulating Part e below 2 If a supply regulates but if the voltage falls outside the tolerances given above see that the supply is properly wired and tubed In par ticular see that normal screen voltages are applied to whichever of these tubes is involved in the affected supply V700 V742 V757 V782 or V7...

Page 3: ...not confine your efforts to the affected supply but make an effort to get all other parts of the instrument into approximately correct operation before deciding that the trouble is centered in the power supply 3 To set CAL ADJ Use 117 line volts With red calibrator knob turned to the OFF position set CAL ADJ bottom front of oscilloscope for 100 volts at Pin 3 of V2i 6 best checked at the connectio...

Page 4: ... effect of the measuring circuit can affect the reading 5 To check sweep and vertical systems for operation Use 117 line volts a Bring up INTENSITY control slowly from CCW position until a spot or glow appears on screen Position spot on screen keeping INTENSITY setting at minimum useful point Bring up Main Sweep STABILITY control from CCW position until sweep is produced Adjust FOCUS INTENSITY and...

Page 5: ...vertically so that the flat tops of the square waves are off the screen both above and below the grat icule Turn up the INTENSITY control so that the spot moving rapidly in the vertical direction makes a visible trace Now set the CUT GEGM adjust ment rear of top deck so that the vertical traces near the ends of the graticule are as nearly straight and vertical as possible In case the CRT is defect...

Page 6: ... with varying line voltage The vertical position of the trace may shift as the power line voltage is changed This shift may be due to either or both of two independent causes l a variation in emission unbalance with heater temperature of the 6CL6 or 6BQ7 vertical driver tubes V508 and V509 or 2 a possible re direction of the electron streams because of the magnetic effects of the heater currents c...

Page 7: ...owly drifts 1 or 2 mm up or down If it does adjust DC SHIFT COMP control so that the drift occuring when the cell is connected is a minimum NOTE This step calls for connecting and disconnecting the cell sev eral times at intervals of several seconds and observing that the trace comes at once to almost its final position each time the cell is connected 13 To set TRIGGERING LEVEL controls to physica...

Page 8: ...nd the Main Sweep TRIGGERING LEVEL control may be touched up slightly to obtain the above result The final setting of the Main Sweep STABILITY control will be in the vicinity of that needed just to produce triggering The final setting of the Main Sweep TRIG GERING LEVEL control will be essentially at 0 After the TRIGGERING LEVEL CENTERING is adjusted reliable triggering must be obtained as the TRI...

Page 9: ...ring with a vertical deflection of not much more than a trace width occurs when the TRIGGERING MODE switch is set to AC FAST and when the TRIGGER SLOPE switch is alternated between INT and INT as above 16 To set INT TRIG DC LEVEL Display calibrator waveform at about 2 or 3 mm vertical deflection KEEP THE DISPLAY CENTERED VERTICALLY about the grati cule horizontal center line Use these settings Mai...

Page 10: ...ATTEN knob CW 5X MAGNIFIER ON ATTEN toggle XI Main Sweep STABILITY CCW Position the s pot on the screen by means of the HORIZONTAL POSITION control Adjust EXT SWP AMPL DC BAL control so that the spot remains stationary on the screen as the EXTERNAL SWEEP ATTENUATOR knob is turned back and forth through out its range 19 To set C2k0 and C25I Settings Main Sweep TRIGGERING LEVEL 0 TRIGGER SLOPE EXT T...

Page 11: ...ring the adjustment of C110 to get a display which alter nates to right and left sides of screen this permits a better appraisal of the square wave Consider only that portion of the waves extending vertically along the middle of the alternating display b Switch the A T T M toggle switch to X10 Repeat Part a of this step but this time adjust with the fingers C100 which affects the slope of the squa...

Page 12: ...e identified by the downward bump occurring when that capacitor is touched with the metal bit of a screwdriver CAUTION The capacitors have 200 volts on them Do not touch them with the fingers Adjust the capacitors of the delay line so that wrinkles of magnitude greater than the trace width are absent and so that the level of the trace is con stant across the top of the square wave Avoid use of the...

Page 13: ...wave This process is to be continued a half turn or a turn of each coil at a time as far as practicable from the viewpoint of obtaining a good square wave response j _ The delay line input coils should now be readjusted for increased in ductance These affect the leading edge only Make equal small increases in both inductances Then make any needed compensating adjustments of the first trimmer capac...

Page 14: ...ION control adjust the SWP CAL control so that the tenth marker falls precisely under the 9 cm graticule line 26 To set the Delaying Sweep LENGTH Set the Delaying Sweep to free run at 1 mil lisec cm Connect the middle black wire of the resistance selector to the upper end of the 12 K resistor R182 in the Delaying Sweep chassis Connect the right hand red wire to the lower end of R182 Connect the le...

Page 15: ... graticule center line by means of the HORIZONTAL POSITION control Then turn the gX MAGNIFIER off and by means of the SWP MAG REGIS control reposition the first marker beneath the center line 31 To check the main sweep timing g sec cm to lOO psec cm ranges After com pleting the step above turn the gX MAGNIFIER off Then a Switch the TIME CM control to 100 psec Position the second marker pre cisely ...

Page 16: ...observed On X2 two mark ers cm should be observed On X5 five markers cm should be observed 32 To set timing of main sweep 10 psec cm to 0 1 psec cm ranges a Preset 0278 and C286 to mid range positions b With TIME CM switch at 10 usee and with MULTIPLIER at XI display 10 psec markers With the HORIZONTALPOSITION control keep the second marker pre cisely under the 1 cm graticule line Adjust C99F on T...

Page 17: ...weep TRIGGERING LEVEL 0 Main Sweep TRIGGER SLOPE INT TRIGGERING MODE AC SLOW HORIZONTAL DISPLAY MAIN SWEEP NORMAL Connect 1 psec marker output of Type 180 to INPUT of plug in unit Cap acitively couple the 30 mc output of the Type 180 to one of the vertical plates of the CRT The value of the coupling capacitor is not at all critical A suggested value is 20 ipf Set the Main Sweep STABILITY control f...

Page 18: ...crease the calibrator output to 2 volts Adjust EXT SWEEP ATTEN knob for a horizontal deflection of 10 cm Throw the ATTEN toggle switch to the X10 position and turn the calibrator output to 20 volts The new horizontal deflection should be 10 cm 1 minor division This procedure checks the cor rectness of the attenuation ratio of the X10 fixed attenuator 35 To set DELAY START ADJ and DELAY STOP ADJ Se...

Page 19: ...er which appears at the 9 cm graticule line Switch the HORIZONTAL DISPLAY control to M A M SWEEP DELAYED and make any slight readjustment of the DELAY TIME MULTIPLIER required to place the magnified marker on the screen Horizontal jitter in the marker position should not exceed 5 mm Neglect slow drift of marker position If the jitter in either of the above tests exceeds specifications you can try ...

Page 20: ...PLIER is set at the 2 0 the 3 0 etc positions for each major graticule line within the middle 8 cm of graticule length Maximum permissible error in this indication is 2 minor divisions on the DELAY TIME MULTIPLIER 37 To check DELAY TIME MULTIPLIER indications on ranges from 10 millisec cm to 200 M sec cm After completing Step 36 display 100 tJ sec cm markers f rom the Type 180 using the 200 p sec ...

Page 21: ...gn the display with the graticule using the HORIZONTAL POSITION control c Set the DELAY TIME MULTIPLIER so that the left end of the brightened por tion of the trace coincides with the 1 cm marker Observe the deviation in minor divisions of the dial reading from 1 0 d Set the DELAY TIME MULTIPLIER dial for the same deviation from 9 0 as that observed from the 1 0 position in Part c Adjust C190 D fo...

Page 22: ...0 psec 100 psec Delaying Sweep TIME CM 2 psec cm 10 psec cm 20 psec cm 100 psec cm Main Sweep TIME CM 0 1 psec cm 1 psec cm 1 psec cm 10 psec cm Ul To check the Delaying Sweep for 0 kc repetition rate Operate the Delaying Sweep in a free running manner with the Delaying Sweep TIME CM switch at the 2 psec cm position and with the LENGTH control set COT Connect atest oscillo scope 10X probe to the r...

Page 23: ...X MAGNIFIER OFF IMPORTAl IT In the following adjustment constantly have the Main Sweep STABILITY control sufficiently clockwise to allow reliable triggering but no further clockwise This waveform should be observed on the test oscilloscope Adjust R6U so that the height of the peak A is two thirds that of the pedestal B The ratio of the height of the peak A to the height of the pedestal B is ideal ...

Page 24: ...eep LENGTH control of the oscilloscope being calibrated Now turn the HORIZONTAL DISPLAY control to the MAIN SWEEP DELAYED position The above results should again be obtained Next turn the HORIZONTAL DISPLAY control to the MAIN SWEEP NORMAL position A display similar to that obtained above should appear on the test oscilloscope this time unaffected by adjustment of the Delaying Sweep LENGTH control...

Page 25: ... screen displaying the calibrator signal The trace should not recur and the READY light should now be extinguished Repeat this operation several times to assure consistent operation J j 6 To check neons and scale illumination With the HORIZONTAL and VERTICAL POSI TION controls move the trace off the screen both up and down and right and left Check that the appropriate neon directional indicators l...

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