Tektronix 545 Manual

TYPE 5*f5 OSCILLOSCOPE
FACTORY CALIBRATION PROCEDURE
Quick check for ong ends, unso dered joints, wire dress, etc. Preset a pots and
trimmers to mid-range, except de ay ine. Check to see that the ort pin connections
are tight. Tighten set screws in both TRIGGER LEVEL knobs just snug enough so that
the knob can be turned on the shaft. Insta TEST LOAD UNIT switched to LO LOAD with
the scope in upright position and turn the INTENSITY and SCALE ILLUM. contro s fu
eft (ccw). If, during the ca ibration there is any question concerning to erances
or imits of any of the circuits, refer to the Factory Specifications on Types 5^1
and 5^5 Osci oscopes.
1. CHECK POWER SUPPLY RESISTANCE TO GROUND
The 100 v wi be more than kOO Q to ground, the -150 v about 3&> 225 v more than
5K Q, 350 v more than 10K Q, and the 500 v supp y above 25K £2. Check transformer
primary for infinite resistance to ground (Pin 1, 2, 3»
2. CHECK TIME DELAY RELAY
Turn the scope on and check time de ay re ay (15 to seconds).
3. CHECK VOLTAGES AND MEASURE RIPPLE AND REGULATION
Adjust -150 v supp y with -150 ADJ. Check 100 v, 225 v, 350 v, and 500 v supp ies
(±2$). Check e evated heater supp ies at transformer termina s. (100 v at 22 and
23, 225 v at 27 and 28, 350 v at 9 and 16, -hv at 2k and 25.)
k. SET CAL. ADJ.
With the SQUARE-WAVE CALIBRATOR OFF adjust CAL. ADJ. for 100 v at CAL. TEST FT.
Turn CALIBRATOR on. Vo tage at CAL. TEST PT. must read between k$ v and 55 v.
(Ca ibrator symmetry ±10/o).
Check power supp ies for proper regu ation with ine at 105 v, TEST LOAD UNIT
switched to HI LOAD; and a so, ine at 125 v, TEST LOAD UNIT switched to LO LOAD.
The ripp e on each supp y in regu ation wi be as fo ows: -150 v, 5 mi ivo ts;
100 v, 5 mi ivo ts; 225 v, 3 mi ivo ts; 350 v, 6 mi ivo ts; 500 v, 7 mi ivo ts.
(Measured with a test scope.)
5. SET HV ADJ.
Turn scope to an upright position and adjust HV ADJ. contro for -1350 v. Read
at front of the 27K resistor at the forward ceramic strip ocated above the crt
shie d. This adjustment can be made convenient y on the 1200 v sca e on the meter
by measuring with respect to -150 v instead of ground. Turn off the scope and in
sta shie d over high vo tage supp y, (if protective s ide rai s are being used,
insta a modified shie d.) With MAIN SWEEP TIME/CM switch at 1 MILLISEC advance
STABILITY and INTENSITY contro s and position the trace on the crt with the VER
TICAL and HORIZONTAL POSITION contro s.
6. CHECK SCALE ILLUM AND POSITIONING CONTROLS
Check the SCALE ILLUM contro . Check position contro s against the position-in
dicating neon ight s. Check scope for microphonics * A ign trace with horizonta
graticu e ines, push crt forward against graticu e and tighten crt c amp. Check
hv regu ation by vaiying ine from 105 v to 125 v. There shou d be no trace b oom
ing.
September, 1959 5^5 - 1

7. SET CRT GEOM ADJ.
Insert from the SQUARE-WAVE CALIBRATOR enough signa so that on y the rising and
fa ing portions of the signa are visib e within the graticu e. Adjust STABIL
ITY and TRIGGERING LEVEL contro s for a stab e disp ay. (The trigger circuit has
not been adjusted so if it is not possib e to obtain a stab e disp ay, adjust the
TRIG. SENS, and/or TRIGGERING LEVEL CENTERING pot.) Adjust GEOM. ADJ. (on P & I
chassis direct y be ow rear hand e) to obtain minimum curvature of the vertica
trace.
8. CHECK DISTRIBUTED AMPLIFIER BIAS
Invert scope and p ace a vo tmeter across the grid ines of the distributed amp
ifier. Adjust VERTICAL POSITION to the point where there is zero vo ts from one
grid ine to the other. With the p us probe of the meter, check the cathode of
each tube in the amp ifier for at east one vo t of bias.
9. CHECK VERTICAL AMPLIFIER BALANCE
Short crt vertica def ection p ates to determine the crt e ectrica center. Short
the grids of the 6DK6's, 6DJ8's, and the 12BY7's, in that order. The unba ance
shou d not exceed 2 mm in the 6DK6 stage, 1 cm in the 6DJ8 stage, and 1 cm in the
12BY7 stage with the overa amp ifier unba ance not to exceed 1.5 cm. Adjust
the graticu e positioning cam to a ign the graticu e center ine with the center
of the usab e area of the crt.
10. CHECK VERTICAL COMPRESSION OR EXPANSION
Position 2 cm of ca ibrator signa up and down within the graticu e ines. A ow
ab e compression or expansion is ±0.5 mm*
11. SET VERTICAL GAIN ADJ.
Switch TEST LOAD UNIT to 250:1 and app y a 100 v signa from SQUARE WAVE CALIBRATOR
and adjust AMFL. GAIN for 4 cm of vertica def ection. Switch SQUARE-WAVE CALIBRA
TOR to 0.2 v. TEST LOAD UNIT to 1:1 and check for 2 cm of vertica def ection.
12. CHECK ALTERNATE SWEEP OPERATION
Check scope for ALTERNATE SWEEP operation by switching TEST LOAD UNIT to DUAL TRACE.
Remove the TEST LOAD UNIT and insta a 53/5*fK PLUG-IN UNIT.
13. CHECK SQUARE-WAVE CALIBRATOR AND VOLTS TO MILLIVOLTS DIVIDER.
Check accuracy of SQUARE-WAVE CALIBRATOR vo tage steps with the K UNIT VOLTS/CM
step switch. Compare the VOLTS range to the MILLIVOLTS range.
*f. ADJUST DC SHIFT COMPENSATION
Vertica y def ect the trace with enough dc vo tage to move the trace about k cm.
This is a very s ow drift and must be watched for a few seconds to see the direc
tion of drift.
15. SET TRIGGERING LEVEL CONTROL
Set the trigger contro s to + INT and DC, TIME/CM to 100 usee. STABILITY fu eft
(ccw), but not to PRESET. Set the test scope VERTICAL INPUT to .05 VOLTS/CM. DC,
set the trigger on LINE, AUTOMATIC and set the sweep TIME/CM switch to 1 MILLISEC.
X2. Use a 10X probe proper y adjusted. Center the trace on the test scope for a
zero reference. Connect the probe to the grid end of the k'JOK resistor from the
aim of TRIGGERING LEVEL pot on scope under ca ibration and set pot to zero vo ts.
Physica y center knob and tighten set screw, Leave TRIGGERING LEVEL contro at
zero vo ts during succeeding adjustments.
September, 1959 5^5 - 2

15. (oont.)
Now repeat the ast step on y 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
tro and set the knob for zero vo ts. (This setting is done at this time for
convenience and has nothing to do with MAIN SWEEP triggering.)
16. SET INT. TBIG. DC LEVEL CONTROL
Position the trace of the scope under ca ibration to the center of the graticu e.
Re-check the test scope zero reference and connect the probe to R8, k'JQ to pin 7
of V8. This point shou d be at zero vo ts. Now switch the scope under ca ibra
tion from +INT to -INT and adjust INT. TRIG. DC LEVEL ADJ. for zero vo ts 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. Switch
test scope VOLTS/CM switch to 0.2 VOLTS/CM. AC. Connect probe to pin 6 of V20,
on scope under ca ibration, and adjust TRIGGERING LEVEL CENTERING so that the
waveform on the test scope is symmetrica . For fina adjustment switch test scope
MAGNIFIER. ON and horizonta y center switching portion of the mu ti waveform. Now
switch the TRIGGER SLOPE switch, of the scope under ca ibration, back and forth
from +LINE to -LINE and at the same time re-adjust TRIGGERING LEVEL CENTERING unti
there is no horizonta shifting of the switching portion of the mu ti waveform.
18. ADJUST TIRGGER SENS.
Turn the TRIG. SENS. pot to the right (cw) unti osci ation occurs at the eading
and trai ing edges of the mu ti waveform. (Test scope probe shou d sti be as in
STEP 16.) Note the amp itude of the spike on the waveform just at the point of os
ci ation. Now turn the TRIG. SENS, eft (ccw) unti this qpike is s ight y ess
than one-ha f (0.5) of the origina size.
19. ADJUST PRESET STABILITY
Use 100 psec/cm. Turn TRIGGERING MODE to AUTOMATIC. +LINE. Turn the PRESET STA
BILITY contro c ockwise unti the sweep triggers. The center arm of the contro
shou d read about 80 v on a meter. Now continue turning PRESET STABILITY unti
the sweep free-runs (trace wi brighten), the center arm on the contro shou d
be between 15 v and 25 v higher. Turn the contro back unti the meter reads ha f
way between the two readings obtained.
20. CHECK TRIGGER CIRCUIT FOR PROPER OPERATION
Obtain 2 mm of vertica def ection from the ca ibrator and see that the trigger
circuit wi work proper y in a 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. variah e VOLTS/CM contro fu right (cw), insert
into the K UNIT from a proper y terminated fast rise-time square-wave generator, a
kOO kc signa of about two or three cm of vertica def ection. A Type 53/5^ F UNIT
can a so be used. Switch the MAIN SWEEP TIME/CM to 1 pSEC, X5. Adjust the trim
mers in the de ay ine with an insu ated too for optimum square-wave response. The
variab e coi s contro the amount of spike on the eading edge of the waveform.
22. MEASURE VERTICAL RESPONSE
Measure the bandwidth with a constant amp itude sine-wave generator, for examp e,
Tektronix Type 190. Turn the generator to 2 me and insert enough signa for 5 cm
September, 1959 5^5 - 3

22. (cont.)
of vertica def eotion, increase the frequency to 30 ®c. The signa shou d sti
be at east 2.1 cm in amp itude.
23. CHECK HF SYNC.
Turn the signa generator to 30 me, switch TRIGGERING MODE to HF SYNC. A stab e
disp ay shou d be obtained with about 2 cm or ess of vertica def ection by ad
justing the MAIN SWEEP STABILITY.
2b. ADJUST SWEEP CAL.
App y 1 mi isec time marks to INPUT. Turn HORIZONTAL DISPLAY to DELAYING SWEEP.
DELAY SWEEP TIME/CM switch set to 1 MILLISEC. Jumper the TRIGGER or EXT. SWEEP IN
to VERTICAL SIG. OUT and adjust STABILITY and TRIGGERING LEVEL for a stab e disp ay.
Adjust SWEEP CAL. for one time-mark per cm. When any timing adjustments are made
a ways make them from the 1 cm ine to the 9 cm ine on the graticu e.
25. ADJUST MAIN-SWEEP TO DELAYING-SWEEP TIMING
Switch HORIZONTAL DISPLAY to MAIN SWEEP. MAIN SWEEP TIME/CM at 1 MILLISEC and ad
just R99M to match de aying sweep timing within .5%. (R99M is on the MAIN SWEEP
TIME/CM Bracket.)
26. ADJUST B.6b
Set HORIZONTAL DISPLAY on MAIN SWEEP DELAYED with DELAYING SWEEP STABILITY fu
right (cw). set MAIN~SWEEP TIME/CM switch to 100 uSEC. Turn the MAIN SWEEP STA
BILITY contro unti a trace first appears. Connect a test scope through a 10X
probe to pin 8 of V37 and observe a composite sawtooth and gate waveform* Adjust
Tfab to the point where the sawtooth portion of the waveform is about two/thirds
of the amp itude of the gate portion. The gate portion of the waveform must be
at east 9 v in amp itude. Each time the setting of R6*f is changed, readjust the
MAIN SWEEP STABILITY as above or an erroneous adjustment of R6b wi resu t. Re
check Step 19.
27. ADJUST MAIN SWEEP LENGTH
Adjust MAIN SWP LENGTH contro for approximate y 10.5 cm of horizonta sweep.
28. ADJUST MAG GAIN
Turn MAIN SWEEP TIME/CM switch to 1 MILLISEC and insert 1 mi isec and 100 psec
markers from the time-mark generator. Turn MAGNIFIER. ON and adjust MAG GAIN
for 5X magnification, ( arge mark every 5 cm and 2 sma marks every cm.)
Check magnifier inearity over the entire sweep ength.
29. ADJUST SWP/MAG REGIS.
With MAGNIFIER ON. position the trace so that the first time mark fa s on the
center ine of the graticu e. Turn MAGNIFIER. OFF and adjust SWP MAG/REGIS.,
so that the first time mark again fa s on the center ine of the graticu e.
Check to see that the MAG. ON and MAG. OFF positions register proper y in the
midd e and at the end of the sweep.
30. ADJUST EXT SWP AMPL DC BAL.
Turn MAG on. Connect MAIN SWEEP SAWTOOTH into vertica INPUT and switch HORI
ZONTAL DISPLAY to EXT. SWEEP. Adjust EXT. SWP. AMPL. DC BAL. for no horizonta
shift of vertica trace when turning EXT. SWEEP ATTEN. back and forth.
September, 1959 5^5 - b

31. ADJUST EXT SWP AMP COMP.
App y a fast rise square wave (about 2 ko) to EXT. SWP. IN. With MAGNIFIER OH.
externa y trigger sweep. Adjust C240 (this wi be a ong time-constant comp
ensation) for optimum square-wave response. Turn MAGNIFIER. OFF and adjust C254
(short time constant). Adjust C267, mica trimmer on the pot braoket. (Very fast
time-constant). C254 and C267 wi be adjusted again for a inear sweep using &
10 me sine wave. Turn MAG on. Now connect the square wave thru a standard 47 ppf
probe into EXT. SWP. IN and adjust C110 for optimum f at top. Adjust EXT SWEEP
IPX ATTEN. compensation C100 and C101. Check s ope switch for correct po arity
(p us is eft).
32. CHECK EXT. SWEEP IN DEFLECTION FACTOR
With 0.2 v of ca ibrator signa fed into the EXT. SWEEP IN. EXT SWEEP ATTENUATOR
switch XI, variab e contro fu right (cw) MAG ON at east one cm of horizonta
def eotion must be observed. Increase ca ibrator signa to 2 v, switch the atten
uator to X10 and check X10 attenuator accuracy (±2$).
33. CHECK MAIN SWEEP RATES
Check the MAIN SWEEP rates as fo ows:
time/cm MULTIPLIER TIME MARK GEN. ACTION
100 usee XI 1 mi isec check sweep rate
100 usee X2 1 mi isec check mu tip ier
100 usee 1 mi isec check mu tip ier
CHECK MAIN SWEEP VARIABLE MULTIPLIER CONTROL
Check MULTIPLIER on the 2.5-1. 5-2, 12-5 positions for sufficient range.
10 MILLISEC XI 10 mi isec check sweep rate
100 MILLISEC XI 100 mi isec check sweep rate
1 SEC XI 1 sec check sweep rate
1 SEC X2 1 sec check mu tip ier
1 SEC &1 sec check mu tip ier
35. ADJUST MAIN SWEEP TIMING
Adjust the fast MAIN SWEEP rates timing as fo ows:
10 pSEC XI 10 psec adjust C99F
1 pSEC XI 1 psec adjust C99H
1 pSEC X2 1 psec check MULTIPLIER
1 pSEC X5 5 psec check MULTIPLIER
.1 pSEC X5 1 psec adjust C99J Posi
tion first marker
to eft off grati
cu e.
.1 pSEC XI 10 me adjust for inear
ity C254 and C267
.1 pSEC XI MAG ON 50 me adjust for inear-
ity C278 and C286
There wi be interaction between the inearity adjustment of C267 and C254 and
the timing adjustments of C99H and C99J so it wi be necessary to it wi be
necessary to go back and readjust these steps over again unti the timing is cor
rect.
36. SET DELAYING-SWEEP LENGTH
Switch HORIZONTAL DISPLAY to DELAYING SWEEP. TIME/CM to 500 uSEC and insta the
September, 1959 545 - 5

56 . (oont.)
DELAYING SWEEP. LENGTH contro imiting resistors. B181B (usua y 12K to 18K)
shunt the ength contro . R182B (usua y kJK to 68K) shunts the 12K resistor be
tween the ength Contro pot and -150 v.
37. SET DELAY START ADJ AND DELAY STOP ADJ.
Use 500 psec/cm de aying sweep speed; 10 psec/cm Main Sweep Speed. Prom the
time-mark generator feed 500 psec marks to the INPUT. Trigger the -DELAYING
SWEEP by feeding from VERT. SIG. OUT with a jumper into TRIGGERING IN. Adjust
STABILITY and TRIGGERING LEVEL for a stab e sweep. Turn MAIN SWEEP STABILITY
fu right (cw) to free-run sweepfe^.SheekJDELAY-TIME MULTIPLIER to 1.00. Adjust
DELAY START ADJ. ti the bright portion just reaches the first time mark. Turn
the MULTIPLIER to 9»00 and adjust DELAY STOP ADJ. so that the bright spot reaches
the ninth time mark. There wi be interaction between these adjustments so it
wi be necessary to go back and forth severa times. Switch HORIZONTAL DISPLAY
to MAIN SWEEP DELAYED and make fina adjustments. Check inearity of the DELAY-
TIME MULTIPLIER at a major divisions.
38. CHECK DELAYING-SWEEP RATES
When timing or checking any other than 500 psec ranges of the DELAYING SWEEP
first turn the DELAY TIME MULTIPLIER to 1.00 and notice the error in de ay start,
this is due to the trigger circuit. Now turn the DELAY TIME MULTIPLIER back to
9.00 p us the error noted at 1.00. ^hen adjusting or checking the faster sweep
ranges this trigger error may be as much as 15 minor divisions.
DELAY SWEEP TIME/CM TIME MARK GEN. HORIZONTAL DISPLAY* MAIN SWEEP TIME/CM
200 uSEC 100 psec MAIN SWEEP DELAYED 10 uSEC
500 uSEC 500 psec MAIN SWEEP DELAYED 10 uSEC
1 MILLISEC 1 mi isec MAIN SWEEP DELAYED 10 uSEC
5 MILLISEC 5 mi isec MAIN SWEEP DELAYED 100 uSEC
ADJUST DELAYING-SWEEP RATES
50 uSEC C190D 50 psec MAIN SWEEP DELAYED 1 uSEC
5 uSEC C190P 5 psec MAIN SWEEP DELAYED 1 uSEC
Check a de ay sweep rates for operation.
* Make rough adjustments in DELAYING SWEEP
40. CHECK DELAY TIME MULTIPLIER LINEARITY
Check DELAY TIME MULTIPLIER on 50 pSEC and 5 pSEC ranges for inear sweep, (two
minor-division error a owed from 1.00 to 9*00).
41. CHECK MAIN SWEEP DELAYED JITTER
Set the DELAYING SWEEP TIME/CM contro to 1 MILLISEC. and MAIN SWEEP TIME/CM to
1 uSEC. Disp ay 1 mi isec markers with the HORIZONTAL DISPLAY contro at DE
LAYING SWEEP. Set the DELAY-TIME MULTIPLIER so that the brightened portion of
the sweep coincides with the marker at the 1 cm graticu e ine. Switch the HOR
IZONTAL DISPLAY contro to MAIN SWEEP DELAYED. The horizonta jitter shou d not
exceed 2 mm. Repeat the process at the 9 cm graticu e ine, jitter at this posi
tion shou d not exceed 4 mm.
42. CHECK RESET MAIN SWEEP AND READY NEON
With HORIZONTAL DISPLAY in MAIN SWEEP norma disp ay about 2 cm of vertica de
f ection from the ca ibrator and set STABILITY and TRIGGERING LEVEL contro s for
a stab e trace. The READY- ight shou d not be on. Switch HORIZONTAL DISPLAY to
September, 1959 545 - 6

42. (cont.)
MAIN SWEEP DELAYED, and turn DELAY SWEEP STABILITY eft (ccw). Press the BESET
MAIN SWEEP button. A sing e trace shou d occur. If the ca ibrator signa is
removed, instead of a sing e trace the READY ight wi ignite when the RESET
MAIN SWEEP button is pressed, then when a signa is fed to the INPUT a trace
wi be triggered and a sing e trace wi occur and the ight wi go out.
Re-check steps 19 and 26.
43. CHECK MAIN-SWEEP HOLD-OFF
Connect a probe from test scope, set for DC input, to the right-hand end of C240.
Set MAIN SWEEP STABILITY fu right few). Check a ranges of MAIN SWEEP TIME/CM
switch for sufficient ho d-off.
44. CHECK DELAYING-SWEEP HOLD-OFF
Now switch HORIZONTAL DISPLAY to DELAYING SWEEP and repeat the ast step*
45. CHECK FRONT PANEL WAVEFORMS
‘ )
With a test scope set for DC input, using a IX (straight through) probe, check
+GATE MAIN SWEEP for a gate waveform of about 20 v amp itude with its base on the
zero-vo t reference ine on the test scope. SAWTOOTH MAIN SWEEP shou d be about
150 v in amp itude with its base ine on a zero reference, except on the two fast
est speeds where its base ine shou d raise about 20 v. DEL’D TRIG, from MAIN or
DEL’G SWEEP shou d be a spike of at east 5 v on a sweep rates. +GATE DEL’G
SWEEP, 20 v, zero reference. Out of the VERT. SIG. OUT there shou d be 2 v of sig-
na for every cm of vertica def ection on the scope under ca ibration. There
shou d be 6.3 v of ac vo tage out of binding post, abe ed 6.3 V 1A AC. This can
be checked with the test scope or a meter.
46. CHECK CRT CATHODE INPUT
Remove CRT CATHODE GND. strap from rear of scope and insert signa from ca ibrator
and check sweep for intensity modu ation. With norma intensity, 20 v of ca ibra
tor signa wi modu ate the trace.
47. MAKE A NOTE OF CRT TYPE AND SERIAL NUMBER AND RECORD ON CALIBRATION RECORD.
September, 1959 545 - 7