Tektronix 535 Manual

TYPE 535
Serial Numbers 101 through 60kk
SUGGESTED FACTORY CALIBRATION PROCEDURE
Preset front-panel controls as follo s:*
POWER SWITCH— OFF.
Main S eep TRIGGERING LEVEL— 0.
" » STABILITY— CCW.
TRIGCER SLOPE— *INT.
TRIGGERING MODE— AC SLOW.
TIME/CM— 10 milli sec.
MULTIPLIER— XI.
5X MAGNIFIER— OFF.
HORIZONTAL DISPLAY— MAIN SWEEP NORMAL.
Delaying S eep TRIGGERING LEVEL— 0.
» » STABILITY-CCW.
SLOPE (toggle)— *.
ATTEN. (toggle)— XI.
TIME/CM OR DELAY TIME— 1 millisec
HORIZONTAL POSITION— MS.
VERNIER— MS.
CALIBRATOR— OFF.
INTENSITY— CCW.
Preset R6U to CW, (This is a small scre driver-slotted potentiometer con
trol ithout shaft, situated at right center of top deck.)
Preset DELAY STOP ADJ to about 30° from CCW stop.
The follo ing controls may be left at the settings here they are found—
that is, they do not require presetting: (l) CAL ADJ, and (2) R99M— the latter
being a small scre driver-slot control mounted on the MULTIPLIER s itch bracket.
Preset the remaining fourteen internal scre driver-slotted controls to MS.
Preset the follo ing capacitors to MS: C2h0 , C2Sh> C278, C286.
With no plug-in unit in position, check the resistances to ground of the
lo voltage po er supplies. (While no tolerances 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 t o sup
plies appear to have the same resistance values, you should check for a possible
short circuit bet een them.
Carry out the follo ing calibration procedure:
1. To check relay time delay.— Remove high-voltage oscillator tube V803 (6AU5).
With po er-test plug-in unit in position, turn POWER s itch on. Check that
the time required for the relay to operate lies bet een 15 sec and U5 sec.
(The thermal time-delay relay, K700, is rated for a U5-sec delay hen 6
volts are applied to it. In the interest of positive contact operation, the
relay is actually operated ith about 9 volts applied, and the operating time
may be appreciably less than U5 sec as a result.) Observe by the flickering
of neon lamp NE95, located above VbO on the s eep chassis, that the main s eep
■“•Front-panel controls are indicated by UNDERLINED CAPITALS. Internal adjustments
are indicated by PLAIN CAPITALS. These abbreviations are used: CW, clock ise;
CCW, counter-clock ise; MS, mid-scale.
August, 1956 FD-535-1
Revised
November, i960

operates hen you turn the Main S eep STABILITY control CW. This flicker is
readily discernible hen the s eep operates at the 10-millisec/cm rate.
(With the main s eep operating, it is probably safe to apply the high volt
age to the CRT even if there should be a iring defect in the circuits affecting
the spot intensity.)
Turn the FOCUS and ASTIGMATISM controls CW. With the Main S eep operating as
above, insert the high-voltage oscillator tube, and observe that the trace can
be turned on and off by means of the INTENSITY control. No set the TIME/CM
control to 100 Msec.
2. To check lo -voltage po er-supply operation.
a. With 117 line volts applied, give a quick check to each lo -voltage supply
to determine that it is delivering approximately the correct voltage. This
quick check helps to reveal overloads or other gross irregularities in oper
ation.
b. Set the -150 VOLTS ADJ control for precisely 150 volts output from the -150-
~ volt supply.
c. Check that the +100-volt supply delivers its rated output voltage ithin ±2%,
Check that the +225-volt, +350-volt and +500-volt supplies deliver their rated
voltages ithin ±3%» (For satisfactory operation of the vertical amplifier, the
350-volt supply must usually deliver at least 345 volts.) If a po er-supply
voltage falls outside these tolerances, proceed as follo s:
(1) Check that the supply affected is regulating (Part e belo ).
(2) If a supply regulates, but if the voltage falls outside the tolerances
given above, see that the supply is properly ired and tubed. In par
ticular, see that normal screen voltages are applied to hichever of
these tubes is involved in the affected supply: V700, V742, V757> V782
or V791. (See DC VOLTAGE MEASUREMENTS pamphlet.)
(3) Try a different comparator tube ( hichever of these tubes is involved in
the affected supply: V712, V742, V765, V782 or V79l).
(4) Try a different set of precision resistors in the voltage divider in the
affected supply.
(5) Finally, if the above steps fail to bring the voltage ithin tolerance,
install a l/2- att composition resistor beneath one or the other of the
precision resistors in the voltage divider of the affected supply. Use
a composition resistor of such value (usually several megohms) that the
supply voltage is brought ithin the tolerance range.
d. Set the test oscilloscope* for a s eep speed of 1 millisec/cm and the s eep
speed multiplier to X5. Set the vertical sensitivity to 0.005 volts/cm.
Using a 2X probe, determine that the po er-supply ripple does not exceed
10 millivolts for the -150-volt, +100-volt ana +225-volt supplies, and
that the ripple does not exceed 15 millivolts for the +350-volt and the +500-volt
*It is assumed that a Type 531 test oscilloscope is used.
August, 1956 FD-535- 2

supplies. These ripple measurements are to be made at the po er-supply
output connections on the bottom deck of the oscilloscope. (The ripple
voltages are usually appreciably smaller than the above outside tol
erances. In particular, if the ripple on the -150-volt supply or on the
+100-volt supply exceeds 3 or U mv, one should suspect a defective com
ponent or a iring error. If components and iring are good, ho ever,
the above tolerances apply.)
The predominant ripple frequency should be 120 cps, rather than 60 cps.
This is evidenced by a display of approximately six cycles over the grat
icule of the test oscilloscope, hen the s eep rate is 5 millisec/cm as
set above.
e. Check the po er-supply regulation by observing that the ripple voltages on
the various supplies do not exceed approximately the tolerances given in
Part d, above, as the line voltage and the loads are varied. Supplies must
remain in regulation ithin the follo ing operating limits:
Lo er limit— line volts, 105>; plug-in set at HI load.
Upper limit— line volts, 125; plug-in set at L(5 load.
NOTE:— If a supply fails to regulate, this failure may be caused by too
small or too large a load, traceable to defective s eep circuits, vertical
amplifiers, or other portions of the oscilloscope. In event of regulation
trouble, do 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 po er 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 connection from that pin to the calibrator
attenuator). The voltage at this point should drop to not more that +55 volts
but not less than +k$ volts hen the red calibrator knob is turned to the
MILLIVOLTS or to the VOLTS position, ith the black calibrator knob in any
position, (This last reading is to assure suitable calibrator symmetry,)
lu To ad.just and check high-voltage supply.—
a. Observe that the high-voltage rectifier tubes are all lighted. If the
"" brightness of the filaments is much different from one tube to another in
the high-voltage supply, consider changing the high-voltage po er trans
former. Replace any high-voltage rectifiers exhibiting a blue glo bet een
the elements, or having the glass cracked around the seals.
b. Set the -1350-volt output of the high-voltage supply to its rated value ith
the HV ADJ control. (Measure bet een the -l50-volt supply output, and the
first left-hand terminal of the ceramic strip adjacent to the CRT GEOM ADJ
control. Use the 1200-volt range on the voltmeter.)
c. Check regulation of the -1350-volt output bet een these limits:
August, 1956 FD-535-3

Lo er limit— line volts, 105; INTENSITY advanced to produce a (defocused)
spot or glo .
Upper limit— line volts, 125; INTENSITY at CCW, to produce no spot.
The regulation is observed by noting that the voltmeter reading remains
nearly constant.
IMPORTANT— The above tests and adjustments are the ones normally required.
Note that they do not directly indicate correct operation of the -lU50-volt
and the +8650-volt portions of the high-voltage po er supply. If the
-Uj50-volt portion of the supply is not operating correctly, you may have
trouble in turning the spot off ith the INTENSITY control, particularly
hen the s eep is operating; or you may experience trouble in obtaining a
spot at all, particularly hen the s eep is not operating. In cases of
these kinds, you should also measure the -lU50-volt output of the supply.
If the +8650-volt output is not operating correctly, the trace may not dis
play normal brightness on the fastest s eeps, even ith the INTENSITY control
turned ell up. An even more important result of improper voltage from the
+ 8650-volt output is the effect upon horizontal and vertical deflection sen
sitivity. It must al ays be kept in mind that trouble ith timing or ith
vertical gain might be due to incorrect operation of the +8650-volt supply
circuits, rather than to the horizontal or vertical deflection systems. In
some cases, it may be desired to measure the +8650-volt output, using t o
voltmeters in series; but you should remember that the loading effect of the
measuring circuit can affect the reading.
5. To check s eep and vertical systems for operation.— Use 117 line volts.
a. Bring up INTENSITY control slo ly from CCW position until a spot or glo
appears on screen. Position spot on screen, keeping INTENSITY setting at
minimum useful point. Bring up Main S eep STABILITY control from CCW position
until s eep is produced. Adjust FOCUS, INTENSITY and ASTIGMATISM controls to
produce a trace of suitable sharpness and intensity.
b. Push CRT for ard so that its face is against the graticule. Rotate CRT so
that the trace coincides ith the horizontal graticule line hen properly
positioned ith the VERTICAL POSITION control. Clamp the CRT in position.
Recheck the trace orientation.
c. Apply 0.2 volts from the calibrator to the input connector of the plug-in unit.
With Main S eep TRIGGERING LEVEL and Main S eep STABILITY controls, obtain a
stable trace. This operation gives a preliminary check on the operability of
the triggering circuits.
No observe the display from a position above and in front of the screen.
Position the display to various parts of the screen by means of the position
controls. Observe any aviness on the internal face of the CRT, Any
appreciable aviness is cause for rejection of the CRT.
d. Set HORIZONTAL DISPLAY at DELAYING SWEEP position. Turn Main S eep STABILITY
CCW, Set delaying S eep TIME/CM at 1 millisec; set Delaying S eep TRIGGERING
LEVEL at 0. Connect VERT. SIG. OUT to TRIGGER OR EXT. SWEEP IN. With EXT.
SWEEP ATTEN. s itch at XI and ith SLOPE toggle s itch at +, adjust Delaying
S eep STABILITY for stable s eep. Increase INTENSITY setting if necessary to
vie trace.
August, 1956 FD-535-ii

e. Using the settings of Part d above, set the Main S eep TIME/CM control
at 100 i-i sec and bring the Main S eep STABILITY control CW to check that
a portion of the s eep is brightened (during Main S eep operation).
No remove calibrator signal, leaving a single trace on the screen.
f. Check the oscilloscope for microphonics. This check is done by rapping
on the test bench, or (not too forcibly) on the top of the panel.
Experience ill tell you ho forcibly to rap and ho much vertical
deflection ill occur in a correctly operating instrument as a result of
microphonics. In any case, any definitely oscillatory type of microphonic
display should indicate that a tube should be changed because of vibration
of its elements. The 6CL6 vertical driver tubes, V508 and V0O9, are common
sources of microphonicsj other tubes in the vertical system may also be at
fault. (Belo SN 1059» 6BQ7's ere used).
6. To adjust vertical AMPL GAIN.— Use 117 line volts. Apply 0.2 volts from cali
brator to INPUT of po er-test plug-in unit. Set AMPL GAIN control (on left
side of oscilloscope, to ards the rear) for 2 cm of vertical deflection (peak-
to-peak). (This is a preliminary adjustment only.)
7. To adjust CRT (SQM control.— Use 117 line volts.
a. Apply more vertical signal from the calibrator than is needed to cover the
~ graticule vertically. Position the display vertically so that the flat
tops of the square aves are off the screen both above and belo the grat
icule. Turn up the INTENSITY control so that the spot, moving rapidly in
the vertical direction, makes a visible trace. No 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 defective, a tilt may be observed in some of these
traces. If the tilt exceeds 1 mm over the 6-cm height of the graticule,
the CRT must be rejected.
b. As a further check on the CRT GEOM adjustment, remove the calibrator sig-
~ nal, and position the single trace first to the uppermost graticule line
and then to the lo est graticule line. The trace should lie along the
upper and the lo er graticule lines ithout noticeable up ard or do n ard
bo ing. A re-touching of the CRT GEOM adjustment should clear up any
normal amount of bo ing.
Observe hether or not a tilt is introduced into the trace at either the
top or the bottom of the graticule. If the tilt in either trace position
exceeds 1 mm over the 10-cm graticule length, the CRT must be rejected.
c. The CRT GEOM adjustment is often rather broad. Within the limits of its
adjustments giving good results under Parts a and b of this step, use that
setting hich gives the least noticeable flare on the screen ( hen the
SWEEP LENGTH control on the top deck of the oscilloscope, and the positioning
controls, are set so that the display lies entirely ithin the graticule.)
August, 1906 FD-535-0

8. To check for compression in the vertical system,— Apply a calibrator signal hich
provides 2 cm of vertical deflection hen the display is centered vertically.
This deflection should not be reduced by more than 0.5 mm hen the display is
raised to the top of the graticule or lo ered to the bottom of the graticule by
means of the VERTICAL POSITION control.
9. To check dc balance of vertical system.—
a. Remove calibrator signal. Short-circuit vertical plates of CRT, and observe
the trace position. With the short-circuit removed, adjust the VERTICAL
POSITION control for the same position of the trace.
b. Short-circuit Pins 2 and 7 of V6o6. Change V606 if the resulting vertical
” shift in trace position exceeds 0.2$ cm. (If at any point in the present
Step 9 it becomes necessary to interchange or replace tubes, redo Parts 5(f),
8 and 9(a).)
c. Short-circuit Pin 2 of V570 to Pin 2 of V580. Interchange or replace these
tubes if the resulting vertical shift in trace position exceeds 1 cm.
d. Short-circuit Pins 2 and 7 of V558, and change V558 if the resulting vertical
shift in trace position exceeds 1 cm.
e. Short-circuit grid of V508 to grid of V509 by operating the push-button s itch
on the panel of the po er-test plug-in unit. Interchange or replace these tubes
if the resulting vertical shift in trace position exceeds 2 cm.
10. To check for vertical shift ith varying line voltage.— The vertical position of
the trace may shift as the po er-line voltage is changed. This shift may be due
to either or both of t o independent causes: (l) a variation in emission
unbalance ith 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, causing a change in the screen-to-plate-
current ratios in V508 and V509. To check for this vertical shift from either
cause:
With the HORIZONTAL DISPLAY s itch at MAIN SWEEP NORMAL, and ith the po er
line voltage at 105 volts,obtain a single trace across the screen. Center
this trace vertically ith the VERTICAL POSITICN control. Raise the line
voltage to 125 volts. If any resulting (fast or slo ) shift in vertical posi
tion of the trace exceeds 0,5 cm, try changing V508 or V509. (if these tubes
must be changed, recheck Steps 5(f), 8, 9(a) and 9(e).)
11. To recheck vertical AMPL GAIN adjustment, and to check the c alibrator attenuator.—
a. Set the AMPL GAIN control so that 0.2 volts from the calibrator produces
"" a vertical deflection of 2 cm.
b. Replace the po er-test plug-in unit ith the 53/5UC plug-in. ^et the input
*" selector at DC. Set the VOLTS/CM control at 0.05 and feed in 100 mv
from the calibrator. Be sure that the red VARIABLE knob on the VOLTS/CM
control is fully CW. A deflection of 2 cm should be obtained. Other
positions of the calibrator attenuator should be checked similarly. The
results should be those tabulated, ithin ±2$:
August, 1956 f d -535-6

Calibrator
VOLTS/CM setting attenuator Vertical
on plug-in unit setting deflection
0.05 100 niv 2 cm
0.05 0.2 volts k "
0.1 0.5 " 5 "
0.2 1 " 5 "
0.5 2 " k "
]_ ^ ti cj 11
2 10 " 5 "
5 20 » U «
10 50 " 5 "
20 100 » 5 "
12, To adjust DC SHIFT COMP control.—
a. After completing the above step, remove the calibrator signal from the
INPUT connector. Leave the INPUT SELECTOR in the DC position. Set the
MODE s itch to "A ONLY" or to "B ONLY." Position the trace at - 3 cm
(that is, 3 cm belo the graticule center line).
b. Connect a 1.5-volt cell (or anohmmeter) bet een GND on the oscilloscope
and the plug-in unit connector. Adjust the VOLTS/CM control on the plug
in unit so that the trace moves to +3 cm. (That is, make the settings
such that t he trace is at -3 cm hen the cell is disconnected, but rises
to +3 cm hen the cell is connected.)
c. Note the position of the trace immediately upon connecting the cell. Leav-
~ ing the cell connected for several seconds, observe hether or not the
trace slo ly drifts 1 or 2 mm up or do n. If it does, adjust DC SHIFT
COMP control so that the drift occuring hen 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 physical center.— (For this adjustment,
the TRIGGERING MODE control should NOT be set to AC AUTO.)
a. Connect a voltmeter from the junction of Rl6 and Rl? to chassis. (Rl6
is connected to the center arm of the Main S eep TRIGGERING LEVEL con
trol, hich is the control nearest the panel in the dual-control assem
bly of hich it is a part.) Set the Main S eep TRIGGERING LEVEL control
so that zero deflection is obtained even on the 3-volt range of the
voltmeter.
b. Loosen the Main S eep TRIGGERING LEVEL knob on its shaft. Turn the knob
on its shaft so that its index points to "0" on the panel, and tighten
the knob on the shaft. Recheck that a voltmeter reading of zero is ob
tained hen the knob index is at "0". Remove the voltmeter connections.
August, 1956 f d -535-7

c. No move the voltmeter ungrounded connection to the junction of R107 and
R108. (R107 is connected to center arm of Delaying S eep TRIGGERING
LEVEL control.) Set the Delaying S eep TRIGGERING LEVEL control so that
zero deflection is obtained even on the 3-volt range of the meter.
d. Loosen the Delaying S eep TRIGGERING LEVEL knob on its shaft. Turn the
knob on its shaft so that its index points to "0" on the panel, and tighten
the knob. Recheck that a voltmeter reading of zero is obtained hen the
knob index is at "0".
111. To adjust TRIGGERING LEVEL CENTERING.— Settings:
Main S eep TRIGGERING LEVEL— 0. TIME/CM— 1 millisec.
TRIGGER SLOPE— +BJT. 5X MAGNIFIER— OFF.
TRIGGERING MODE— AC SLOW. HORIZONTAL DISPLAY— MAIN SWEEP NORMAL.
a. Display calibrator signal. Set calibrator output and the VOLTS/CM s itch
for 3 or 4 mm of vertical deflection. Set Main S eep STABILITY control and
the TRIGGERING LEVEL CENTERING control so that a stable display is obtained.
Then make further adjustments of TRIGGERING LEVEL CENTERING so that the s eep
triggers equally ell on +INT and -INT settings of the TRIGGER SLOPE s itch.
Note: The Main S eep STABILITY control and the Main S eep TRIGGERING LEVEL
control may be touched up slightly to obtain the above result. The final
setting of the Main S eep STABILITY control ill be in the vicinity of that
needed just to produce triggering. The final setting of the Main S eep TRIG-
GERING LEVEL control ill be essentially at "0". After the TRIGGERING LEVEL
CENTERING is adjusted, reliable triggering must be obtained as the TRIGGER
SLOPE s itch is moved back and forth bet een the +INT and the -INT positions
ithout touching the Main S eep TRIGGERING LEVEL or Main S eep STABILITY
controls.
The above is a preliminary adjustment of the TRIGGERING LEVEL CENTERING con
trol. The final adjustment is described under Step 15, belo .
b. Check the polarity of the TRIGGER SLOPE s itch on +INT and -INT positions.
The leading edge at the left end of the graticule should be a rising edge
hen the s itch is in the +INT position, and it should be a falling edge
hen the s itch is in the -INT position.
15. To adjust TRIGGER SENSITIVITY control.— Settings of the oscilloscope being cali
brated:
Main S eep TRIGGERING LEVEL— 0.
Main S eep STABILITY— CCW.
TRIGGER SLOPE— +LINE.
TRIGGERING MODE— AC SLOW.
HORIZ. DISPLAY— MAIN SWEEP NORMAL
TIME/CM— 100 usee.
5X MAGNIFIER— OFF.
MULTIPLIER— XI.
INTENSITY— CCW.
Settings of test oscilloscope:
TRIGGER SLOPE— +LINE. TIME/CM— 1 millisec.
August, 1956 FD-535-8

TRIGGERING MODE— AC SLOW.
HORIZ. DISPLAY— INTERNAL SWEEP 5X MAGNIFIER— ON
VOLTS/CM-^27~
Connect 2X probe of test oscilloscope to Pin 1 of V20 (or to lead from that
pin to the TRIGGERING MODE s itch). With TRIGGER SENSITIVITY turned CW,
the aveform of Fig. 1 should be seen on the test oscilloscope, (Figure
may be inverted. If so, s itch to -LINE triggering on test oscilloscope.)
A
The TRIGGER SENSITIVITY control should no be gradually turned CCW until
the self-oscillation indicated at A just dies out. The result is a dis
play sho n in the solid line of Fig. 2, The TRIGGER SENSITIVITY control
should be turned further in the CCW direction until the peak B drops to a
point C (dotted line, Fig. 2) hich has a height above D equal to one-
half its original height. —
After this adjustment, repeat Step lli(a), but this time obtain reliable
triggering on signals hich produce a vertical deflection of not more than
a trace idth.
Check that reliable triggering ith a vertical deflection of not much more
than a trace idth occurs hen the TRIGGERING MODE s itch is set to AC FAST,
and hen the TRIGGER SLOPE s itch is alternated bet een +INT and -INT as
above.
16. To set INT TRIG DC LEVEL.— Display calibrator aveform at about 2 or 3 mm
vertical deflection. KEEP THE DISPLAY CENTERED VERTICALLY about the grati
cule horizontal center line. Use these settings:
Main S eep TRIGGERING LEVEL— 0. TRIGGERING MODE— DC.
TRIGGER SLOPE— +INT. TIME/CM— 1 mflTisec.
5X MAGNIFIER— OFF. MULTIPLIER— XI
HORIZONTAL DISPLAY— MAIN SWEEP NORMAL.
Adjust the Main S eep STABILITY control and the INT TRIG DC LEVEL con'
trol for a stable trace. With correct a djustment of the INT TRIG DC
LEVEL, the s eep ill trigger equally ell on +INT and on -INT.slope
settings, ith a given setting of the Main S eep STABILITY control.
17. To check AC AUTO operation.— Settings:
Main S eep TRIGGERING LEVEL— CW.
Main S eep STABILITY— CCW.
TRIGGER SLOPE— +INT.
TRIGGERING MODE— AC AUTO.
Use no signal input. Operation in the
TIME/CM— 100 jisec.
MULTIPLIER— XI
5X MAGNIFIER— OFF.
HORIZ. DISPLAY— MAIN SWEEP NORMAL
AC AUTO mode is indicated if, upon
August, 1956 FD-535-9

advancing the Main S eep STABILITY control slo ly CW, you obtain a trace, and
if further advance of this c ontrol results abruptly in a brightening of the
trace. (The first trace results from triggering of the s eep by the trigger-
shaper multivibrator operating in a free-running manner at about 50 cps. The
brightening occurs hen the s eep-generating circuits themselves become free-
running at advanced Main S eep STABILITY settings.
No apply sufficient calibrator signal to provide 2mm of vertical deflection.
Set the TIME/CM control to 1 millisec. A stable display should be obtained
hen the Main S eep STABILITY control is set for triggered operation of the
s eep. A further check on the AC AUTO mode is obtained by removing the input
lead at the calibrator connector. Usually sufficient 60-cps signal ill be
picked up in the room so that if the bare end of the lead is held in the hand,
a (distorted) ac ave can be obtained on the screen. The TIME/CM and VOLTS/CM
controls should be s et to obtain a display of suitable size on the screen, and
it should be checked that a stable display can be obtained by setting the Main
S eep STABILITY control if necessary,
18. To adjust EXT SWP AMPL DC BAL.— Ground EXTERNAL SWEEP IN. Set:
HORIZONTAL DISPLAY--EXT SWP. EXT. SWEEP ATTEN. (knob)— CW.
5X MAGNIFIER— ON." ATTEN. (toggle;— XI.
Main S eep 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 S eep TRIGGERING LEVEL— 0.
TRIGGER SLOPE— +EXT.
TRIGGERING MODE— AC SLOW.
HORIZONTAL DISPLAY— EXT. SWEEP.
SLOPE (toggle)— +
VOLTS/CM— 10.
5X MAGNIFIER— ON .
ATTEN. (toggle) — XI.
EXT. SWP. ATTEN.— CW.
TIME/CM— 1 millisec.
"MULTIPLIER— XI.
CALIBRATOR— 0.5 volts.
a. Connect 1-kc output from Type 105 to TRIGGER OR EXT. SWEEP IN. Have the
Type 105 terminated at its output connector ith a 52-ohm terminating resis
tor. Use a 52-ohm cable, terminated at the oscilloscope end in a 5*1 (lli-db)
52-ohm L pad. Connect the Sync Output of the Type 105 to TRIGGER INPUT.
Connect SAWTOOTH MAIN SWEEP to input of plug-in preamplifier. Adjust
STABILITY for a stable square- ave display hich is presented vertically,
rather than horizontally, across the screen. Set the Output Amplitude con
trol of the Type 105 for about 2 cm of horizontal deflection. Adjust C2i|0
(at right rear of top deck) for best square- ave r eproduction.
b. Next, turn the 5X MAGNIFIER off, and increase the Output Amplitude setting of
— the Type 105 so that a horizontal deflection of about 2 cm is again obtained.
Adjust C251i (near C2U0) for best square ave reproduction.
August, 1956 f d -535-i o