Tektronix 475 User manual

COMMITTEDTO EXCElLENCE
PLEASE CHECK FOR CHANGE
INFORMATION
AT THE REAR
OF THIS MANUAL.
Tektroni x, Inc.
P.O. Box 500
Beaverton, Oregon 97077
070-2039-00
475
OSC ILLOSCOPE
AND
DM44 DIGITAL
MULTIMETER
OPERATORS
I NST R U C T IO N M A N U A L
First PrintingJUL 1976
Seria l N umber Revised OCT 1981
Copy right s 1976 Tektronix, Inc. All rights
reserved. Cont ents of this publicatio n may not be
reproduced in any
fo rm without the wri tten
permission of Tektronix, Inc.
Produc ts of T ektr onix, Inc, and its sub sidia ries
are
cove red by U.S. and fore ign pa ten ts and /o r
pending patents.
T
EKTR ONIX, TEK , SCO PE·MO BILE. and ~
are registered tradem arks of Tekt ron ix, Inc.
TE
LEO U IPMENT is a registered trade mark of
Tektr onix U.K. lim ited.
Pr
in ted in U.S.A. Specifi ca tion and price c hange
privileges are reserved.

TA BLE OF CON T ENTS
Page Page
LIST OF ILLUS TRATIONS
;,
BASIC OSCILLOSCOPE DISPLAYS "
LIST OF TABLES ,
NORMAL SWEEP DISPLAY
'.
MAGNIFI ED SWEEP DISPLAY
17
BEFORE OP ERATING
1DELAYED SWEEP DISPLAY 17
INTRODUCTIO N1MIXED SWEEP DISPLAY
,.
SA FETY INFO RMATION
,X-V DISPLAY
,.
OP ERATING vO LTAGE
2SI
NGLE SWEEP DISPLAY
"
Line VOllage Selection
2
Regulating Range serecnco
2
OM44 DISPLAYS AND MEASU REMENTS 2.
OPT IONS
3RESISTANCE
2.
CONT ROL S,CO N NEC TORS,AND
VOL TS 22
IN DICA TORS
4TEMPERATURE 24
VER TICAL
4Accuracy
Check
24
DIS PLAY
7TIM E AND l fT lME 27
DM44 7
TRIG GER •A
PPLICATIONS AND MEASUREMENTS 2.
HQRIZQN TA_, CALIBRATOR , AND POWER
'2
REAR PA NEL
14 PRELIMINARY 2.
LEFT SIDE PANEL 14 SIgnal Ground 2.
RIGH T SID E PANEL 14 Input Coupling Capacito r Pr echa rg ing 2.
REV A JAN 1981 475/DM44 Operalors
TABLE OF CONTENTS (cont)
APPLICATIONS AND MEASUREMENTS (coni) Page APPLI
CATIONS AND MEASUREMENTS (cont) Page
OPERATOR'S ADJUSTMENTS AND CHECKS
2. PHASE Di ffEREN CE MEASUREMENTS 42
Trace Rotation 2. HIGH RESOL
UTIO N PHASE DIFFERENCE
Probe Compensation
2.
MEASUREMENTS 43
Vertical Gain Check 3. PULSE JITTER MEASUREMENTS 44
Basic 475 Timing Chec k 3. DELAYED OR MIXED SWEEP
DM44 Timing Check 3.
MAGNIF ICATION 45
Extemat Honzontat Gain Check 31 Magn ified Sweep Starts A ll er Delay 45
PEAK-TO-PEAK VOLTAGE Triggered Delay Sweep Magnification
4.
MEASUREMENTS- AC 31
INSTANTANEOUS VOLTAGE
MEASUREMENTS
-D C32 Baslc 475 Delayed or Mb ed Sweep TIme
ALGEBRAIC ADDITION 34 Measurements
4.
COMMON MOD E REJECTION 35 TIME Dif FERENCE BETWEEN REPETITIVE
AMPLITUDE COMPARISON PULSES (BASIC 475) 4.
MEASUREMENTS 36 TIME DURATION MEASUREMENTS
TIME-DURATION MEASUREMENTS 37 (BASIC 475) 4'
FREQUENCY MEASUREMENTS 38 FREQUENCY MEASUREMENTS (B
.&.S IC 475) 50
RISETIME MEASUREMENTS
3.
TIME Dif FERENCE BETWEEN TWO PULSES
TIME DIFFERENCE BETWEEN TWO FROM DIFFERENT SOURCES IBASIC 475) 5'
PULSES FROM DIFFERENT SOURCES 4. RISETIME (BASIC 475) 52
TIME COMPARISON MEASUREMENTS41 MIX (BASIC 475) 53
"475/DM44 Operators REVA JAN 1981

TABLE OF CONTENTS (cont)
OM44 Delayed or Mi xed Swe ep Time Page OPER
ATO R'S SPECIFICATIONS (c oni) Page
Mea sure ment s54
TIME OIFFEFIENCE BETWEEN REPETITIVEZ AXIS I
NPU T65
PULSES (DM44) 56
OUT PUTS 65
TI ME DU RAT ION ME ASURE MEN TS (DM 44) 57 AC POWER SOURCE 65
FREQUENCY MEASUREME NTS (DM44) 58
ENVIRO NME NT AL 65
TIME DIFFE Fl ENCE BETWEE N TWO PULSES OM44 DIG
ITAL MUL T1 METER 66
FROM DIFFERENT SOURCES (DM44) 58 RES
ISTANCE 66
RISET IM E (DM44) 60
TIME
66
MIX (DM 44) 61 l /T IME 66
TEMPERATURE 66
OPERATOR'S SPECIFI CATI ONS 62
DC VOLTAGE 66
475 OSCILLOSCOPE 62
VER TICAL
62 ACCESSORIES68
T RIGGERING
63
DIF FERENT IAL TIME MEASUREMENT 51 ANDARO ACCESSORIES 68
(BAStC 475) 63 OPT IONA L ACCESSORIES 68
DIFFERE NTIAL TIME MEASUREMENT
iD M44) 64
OPTIONS 6.
HORIZONTA L64 OPTION 16'
x-v 64 OPTION 4
6'
CALI B RAT OR 64
OPTION 769
REV A JAN 1961 475 /DM44 0p erst or siii
LIST
OF
ILLUSTRATIONS
Page Page
Fig 1.
Regulating range selec t or and line Fig . 17. Com m
on -m ode reject ion. 36
fuse. 3Fig. 18 Time d
urat ion. 38
Fig 2. Vertica l con
trol s. connect ors,
00'
Fig , "Risetime.
3.
motcatcrs. 4Fig , 20. Time di
fference betw een two pu lses
Fig. 3.
Disp lay and DM44 con tro ls, from d
iffer e nt so urces, 40
con n ecto rs, and in dic a tor s6Fig, 21 . Phase difference. 43
Fig. 4. Tr
igge r co nt r ols . conn ecto rs, and Fig 22 High
-re solution phase di ffer enc e. 43
tn otca tors. 8Fig 23 Pulse jitter. 44
Fig. 5. T
ng ger con t rols . connec to rs. and Fig 24
Delay ed s weep magnification. 46
in dica tors, 10 Fig 25 T ime di ffe
renc e between repetitiv e
Fig 6Hor izo nta l, c alibr ato r, and po wer
pulses ,
4'
co r arors. con necto rs, and in dic ato rs. 12 Fig. 26 Time
dur a tion .50
Fig 7. Rear panel and l eft sid e panel con trols,
Fig 27 . Time difference bet
ween tw o pu lses
co nnectors, and in dic ato rs. 15
from di ffe rent sources .51
F, .8. Resistance 21 Fig . 28 Risenm e. 53
Fig •• Volts. 23 Fig
2.
Time di ffer ence be tween repe tit ive
Fig 10. Te
mp era ture
25
pulses.
56
Fig 11. Pr ob ecor-ipensatton
2.
Fig . 30 Time
du ra tion and fre quency
Fig 12. Basic 475 timing check .30 measu re
ments ,57
Fig
13 DM44 timing check .31 Fig. 31
Tim e di f ference between two pulses
Fig 14. Peak-to-peak
voltage of a wave form ,32 from
diff erent sou rces,
5.
Fig 15. Insta
nt aneous voltage measuremen ts. 33 Fig . 32 Rtsetime.60
Fig 16. Algebraic addition. 35
I,
475 /DM44 Operator s@

LIST OF TABLES
P age
Page
TABLE 1 Regulating Ranges
TABLE 2Resistance Ranges
TABLE 3 Valls flanges
2
20
22
TABLE 4 Centigrade 10 Fahrenheit Conve rsion
TABLE 5 OM44 Delayed Sweep Displays
2.
54
@47S
/DM44 Operators ,
1039·15
20J!H2
475/DM44 O ~ ralo rs
@

BEFORE OPERATING
INTRO OU CTI ON
The Tek tro nix 475 Oscilloscope is a dual-ch annel
po
rtable Instrurr en t. The dual-channel oc- to-zan MHz
vertical system provides calib rated de flect ion factor s from
2 millivol ts to 5 vorts rofvrsron. Th e s weep trigger ci rcui ts
are capable of s
table triggering over the full ban dwidth
capabil ities 01the vertical deflec tion sys tem .The horizo n-
tal deflection system provides calibrated sweep ratesfrom
0.5 second to J.01 m icro second /divis ion a long wit h
delayed sweep feat ures for accu rate relative -l ime
measureme nts. A Xl 0 m agnifier exten ds the calib rated
sweep rate to 1nanosecond/division. The instrument
operates over a wide varia tion of line vo l tages and
f
reque ncies . Ma xim um power consumption is a bou t
100
watts
The Te ktronix DM 44 Digi tal Mufnmeter measures 0
ohm to 20 rneqobrns.0oc volt to 1200 dc volts ( ~or I,or
(using th e te
mp erature p rob e) - 55 °C to f150° C The
measurem ent is display ed on a 3-112 digi tal display whil e
the oscilloscope operates normally.
The digital mu tnrneter and oscilloscope comb ine to
prov ide a dig ital readout of the time bet ween any two
points on the oscilloscope dis play . Both time measure-
ment po ints are d isplayed on the crt at the same time . The
1 /TIM E function can p rovide direct mea surement of
frequency.
SAFETY INFORMATION
The ins trume nt is designed to oper ate from a single-
phase pow er source with one ot the cu rren t-car rying
conducto rs (the Ne ut ral Conduc tcr) at grou nd (earth)
pote ntial. Ope ra tion from pow er sourc es where both
cur r ent-ca r rying conduct ors are live with res pect to
ground (such as phase-to- phase on a thre e-wire sy stem)
is not r ecommended , since only Ihe line Conduc tor has
over-curren t (fuse) protec tion wi thh the instrument
The ins trument has a mree-wue po we r cord wit ha
m roo -te rmtne! polarized plug f or connec t ion to the po wer
source and safety-earth. The ground (e art h) terminal of
the plug is dire ctly connec ted to the Inst rum ent frame For
erectrtc-sbock pro tec tion ,lnsert thfs plug only in a mat ing
out let wit hasafe ly-earth contact.
@ 475/DM 44 Operat ors 1
OPERAT ING VOL TAGE
Ii'" or...- ... ...- ...- ...... ...
~ C A U TI ON ~
\ .. '1' r ... ' ... ' ",-'
This ins trum enl may be damaged if operated with
me lin e vol lage selec tor SWi tch or the reg u latin g
range selector set
'or Ihe wrong appl ied lin e v oltage
or if tne wrong line fuse is used.
lin e Voltage Selection
This instrument operates from either a 115-v ott or a
za c -vort nominal line voltage sou rce . 48 to 440 hertz . To
convert from one nominal line voltage range to the other ,
m
ove the line Voltage Select or switch (loca ted on side
pane l) to indicate the correct nom inal vo lt age . A 115 -to -
230 vo lt
adapte r may be requ ired tortne nne -cere plug. Be
sure to use the correct line fuse for the line voltage
selected (see Table 1).
R eg ulating Ran ge Selection
The Regu lating Range Selector assembly (located on
the rear
panel ) is set for one of the line voltag e ranges
shown in
Table 1. Italso conta ins the line fuse tor overtoao
prote ction
To ch ange the reg ulating range :
t . Disco nne ct the instrument from the p ower so ur ce.
2. Lo
ose n the two ca ptive sc rews that ho ld the cover
on
the selecto r assembly: the n pu ll to remove the cover.
3. P
ull out the ra nge select or switch bar (see Fig 1)
Select a
range from Table 1 wh ich is centered ab o ut the
aver
age line voltage . Slide the bar to the des ired position
and plug it in.
Push the cover on and tighte n the screws
TABLE 1
Regulating Ranges
Regulatin g Range
Range Selector
tts -vcns 230 -Vo ll s
Swllch Positi on Nom i nal N om inal
LO (Switch
bar in
lower holes ) 99 to 121 v olts 198 to 242 volts
M (Switch bar in
m idd le ho les) 104 to 126 vo lts 207 10 253 v olts
HI (Switch bar in
uppe r ho les) 108 to 132 volts
216 to 264 volts
Fuse Size 1.5 A 3AG 0.75 A 3AG
Fas t-b low Fast-blow
24
75/D M44 Ope rators
@

OPTIONS
Options are available to a lter osci lloscope performan ce
to
meet parti cu lar applications. A number in either MOD
slot (see Item 53. C ontro ls, Connecto rs, and Ind ic ato rs)
indicates a mod ified osci llo scope.
@
LINE F USE
Fig. 1. Regulaling range selector and line Iuee.
475/DM44 Opera
tors
CONTROLS , CONNECTORS AND INDICATORS
3
~
(2
cp
I ii
0 0 0 0 0 1 10 00 0
fu
~
~ -
~
~
1
dJR
1
( 6
@~ O l 'I I
.. (;' o0B8
><
:'- ~ B
~
4
2 Y --
•J:
~
:-
@~
[ \@
@@ O O
W
7 ~
10
2oj9-3
Fig. 2. VertIcal conlrols. connectors, and IndIcators.
VERTICAL
1. CH 1 and CH 2 VOLTS /DIV - Selecl s the verti cal
de
flection facto r in a 1-2-5 sequence (VAA control must be
in
the ca l ibrated detent for the indi cated defle ction factor).
2. VOLTS/
OIV Readou t- Consists of two small lamps
for each ch a nnel . located beneath the skirt of each
VOL TS /D IV knob . One or the othe r lamp will light up to
indicate the correct deflection factor when a probe with a
scale-switch ing connector is used. A probe without this
connector tights the xt lamp.
3. VAR- Provides
contin uo usly var iable u nceueratec
deflec tion fact ors between the ca l ibrated sett ings of the
VOL TS/DIV switch , and extends the maxtrnurn vertical
de flection to at least 12.5 v olts per d ivision (5 vol t
pos
ition) .
4.
UN CAL La mp - Ind ic ates 110 hen the VAA
VOL TS /DIV control is out ottne calibrat ed detent and the
vertical deflec tion factor is uncatib rated .
4475 /DM44 Ope ra tors
@

5. POSITION - POSitions the disp lay ver tically, In the
X-V mode. the CH 1 POSITION con trol pos i tions on the X
a
xis (ho rizon tal'y] and the CH 2 POSITION control
positions on the v-aos (ve rtically).
6. CH 1 OR X and CH 2 OR V- Inp ut connectors for
applica tion of exte rnal signals to the inputs of the vertical
ampli fier, In the X-V mode of operation, the signal
connected to t heCH 1OR X connector provides horizon-
tal de flec tion and the signal connected to the CH 2 OR Y
connector provtces vertical deflection ,
7,
AC -GND -OC - Selects the method used to couple a
signal to the inpu t of the ver tical amplifier, In the AC
position, sig nals are capacitively coupled to the ver tical
ampli fier, The cc cornpcnen t of the inpu t signal is blocked
In the GND position, the Input of 'he vertical am plifier is
disconnec ted f rom the input connector and grounded to
allow the inp ut coupling capaci tor to precnaeqe. In the DC
posi tion , all components 01 the input signa l are passed to
the input ampli fier.
8, VERT MODE - Selects mode of ope ra tion for ver-
tic al am pli fier system
CH 1
Chan nell only is displayed.
ALT: Provides dual-t race displ ay of tne siq nats ct both
ch
annels . Dis play isSWitched b etwe en ch annels at the end
of
each sweep , Useful at s weep rates faster than about 50
microseconds/divisi on .
ADD
Signals applied to the CH 1 and CH 2 input
connectors are alge braically added. and the atqeb rarc
sum is displayed on the cr t. The INVE =1T swi tch in Channel
2 allows the display to be CH 1 plus CH 2 or CH 1 minus
CH 2. Usefu l for common-mode rejec tion to remove an
undesired Signal or for oc offse t.
CHOP: Provides dual- trace dis play of the s ignals of
both channels . Disp lay is SWitched betw een channels at a
repetition rate of appro ximatel y 250 kHZ. Useful at s weep
rates slower than abou t 50 microseconds /division. or
when a dual-trace, single-sweep display is required
CH 2: Ch
annel 2 only is displaye d It mu st be selected
In X-V operation
9. 100 OR 20 MHz BW /TRIG VIEW - Three-purpose
SWi tch tha t l imits the band width of the v ert ical a mpl ifier
system to app ro xima tely 100 MH z (first detent) o r20 MH z
(second deten t) when pulle d. or when pressed. caus es the
s
ignal applied to A Trigger Generator to be d isplayed on
the crt.
10, INVERT- Channel 2 dlspl a)' is i nvert ed in the
INVERT (bu tton In)
position
6
@
18 19
ON SIDE
PAN EL
475/DM44 Ope rato rs
21 ~
•
-uo
@~
:@~
@ 11
Du• @
• 0
~ Bii
@:
0
@O
••
@)
@
Fig. 3. Disp lay and DM44 co ntrols, con nec tors , and indlcal on .
475 /DM 44 Oper ato rs @
5

DISPLAY
11. Inlern al Gr aticul e-cE timin ates parallax. atsetr-ne.
amp litude and n-eesuremeot points are indicated at the
le
ft-hand qra ticule edge .
12.
BEAM FI NDER ~ C o m p r e s s e s the display to wi thin
the gra ticule area independently of display position or
applied s ignals and p rovides a visible viewing level.
13.
INTEN SITY- Controls b righ tness of the crt dis-
play .
14. FO CU S - Adjusts for optimum display de fini tion .
15. SC
AL E ILL UM - Controls gralicule illumination
16. ASTIG- Used in conjunction with the FOCUS
contro lto obtain a well-defined display . II coes oot require
read jus tmen t in normal use .
17. TRACE RO
TA TION - Adjusts trace 10 align with
the ho rizontal q raticule lines .
DM44
18. Input Connectors- Two banana jac ks provide +
(red) and COM (otack] inputs for voltage and resis tance
only ,
19. Probe
Co nnec tor - Input connector f or the
temper atur e probe .
20. Rea dout - Negat ive
po la rity indication is
automatic for negativedcvoltage anc temperatu re with no
po lari ty indication for posi tive measurem ent. A blin king
display indica tes overrang e. The decimal point is pos it ion-
ed by the FUN CTI ON and RAN GE controls tor mutttme ter
operat ion and by the oscilloscope A TIM E /D IV swi tch in
the TI ME or l
/TI ME modes .
21.
RAN GE - Selects trom .2 V to 1,2 kV dc in 5 ranges
(1200 volts is the ma ximum sale Input in the 1,2 kV de
mode) : trom 200 ohms to 20 rneqoh-ns in 6ranges.
22. FU
NC TIO N- Selects VOLTS, OH MS, TEMP (QC).
l/TIME .or TIME functions of the DM44
23. Scale Factor Lamps- Two lamps.
In
the TIME function, the Readout and Sca le Fac tor
Lamps indicate the lime difference be tween the two
intens ified zones on the crt display , One lamp or the other
will light 10 indicate ms or ps , No lamp lit indicates
seconds .
In the l
/TIME function the Re adout and Sca le Factor
Lamps indicate the number ot m easured intervals per un it
of
time . One larnpor tne o ther will light to indicate i ntervals
per ms (Vms lamp) or I nt ervals pel ps (l ips lamp ). No
0 0 29
26
27
475 /DM44 O perators
la mp tit in dic ates intervals per second, It the du ration of
one eve nt is being measured. the Readou t and Scale
Fac tor Lamps indicate frequency, The 1/ms l amp in-
dicates kHz . the l /lJs lamp indicates MHz, and no lamp lit
indica tes Hz.
24.
lJ. TIME - Used in con junction with the DELAY
TIME
POSITION COn tro l in the TIME and l /TI ME tun c-
ttons. The lJ. TIME con trol mov es only the time-
me asu rement point. The DELAY TI ME POSITIO N con trol
mov es both the reference point and the t ime -
measu remen t point With the time-m easurement po int to
the lell of the re ferenc e point the Re adout indicates a
n
egative time dil1erence .
NOTE
You can modi fy your ins trumenf 10 make the DELA Y
TIME
POSITION control mo ve only Ihe reference
point. The procedure for making tllis modification is
located in Ihe Maintenance section of the DM44
Service manual,
TRIGGER
25. TR IG MODE - Determines the mode of trigger
operation tor A Swe ep
7
2039-5
Fig. 4. Trl9ger controls, conn ectors, and indicators.
AUTO. Sweep is initiated by the app lied t rigge r signal.
In the absence of an adequ ate trigger sig nal , or if the
trig ger rep etitio n rate is l ess than about 20 hertz , the
s
weep free runs and provides a brig ht reference t race .
B475 /DM44 Op erato n@

N ORM : Sweep is ini tiated by the appl ied tr igger signal.
In
the absence of an adequ ate tr igger signal, there is no
trace. When
the tr igger rate is too row lor A UTO use
NORM .
SINGL SWP: When this p ush butt on is pushed . the A
Sweep operates in the single sweep m ode . After a single
sweep is dtsptavec. further sweeps c annot be presented
until the SINGLE SWP butt on is aga in pushed II is usef ul
w
hen the signa l to be dis played is not repetitive or varies in
amp litude . shape or time causing an uns table conve n-
tional display . It can also be used to pho tog raph a
nonrepennve signal.
26.
READ Y Lamp - Indicates A Sweep is " arme d" and ,
upon
receip t of an adequate t rigger signa l, will present a
single -sweep disp lay ,
21. TR IG
Lamp - Indicates that A Sweep is triggered
and will produce a stable d isplay. It is usefu l for selling up
the tr
igg er circ uits when a trigger s ignal is avai lable
without a display on the crt (for example , whe n using
ex
ternal triggerS'I.
28. A
TRIG H O L D OFF ~ P ro v i d e s continuous con trol
of time between sw eeps . Allows tr iggering on aper i odic
signals (such as complex dig ital wo rds }. In th e fully
clockwise pos tncn (8 ENDS A),A sweep is rese t at the end
0 18 sweep to prov ide the fastest ooss.ote eweeo repeutton
rate for delayed-swe ep pre se ntat ions and l ow-repet iti on
rate signals, Use the A trigg er
cont rols f or the best
poss ible display befor e using the A
TRIG HO LDOF F
contr ol.
29. CO U
PLING - Determines meth od used to coup le
signals to the trigger generator circuit .
AC : Sign als are capaci tivety coupfed to the inp ut of the
trigger generator . Dc is rejected and s igna ls below abo ut
60 Hz are attenu ated
LF HEJ : S
ignals are capacttively coupled to the input
of
the trigge r circ uit. Dc is re jected and signals below
abo ut 50 kH Z are attenuated .It is useful for providing a
stab le d isplay 0 1 the h igh -freq uency components of a
comple x waveform .
HF REJ :
Signals are cececmverv coupled to the inpu t
01 the trigger circ uil. Dc is rejected and signals below
about 60 Hz and above about 50 kHz are attenua ted . It is
usetut
for p rovidi ng a stable display 01 the low-frequency
components of a comple x waveform .
DC : All
componen ts of a trigger signal are co up led to
the in
put of the trigger circuit. It is useful for pr oviding a
stabl e d isplay of l ow -f requency or low -repeti t ion rate
signa ls. except the combination of the ALT (dual trace )
mo de w ith the trigger SOURCE swi tch in NORM.
@
32
415/D M44 Opera tors
30. SLOPE- Selects the slope of the trigge r s ign al that
starts the sweep .
9
~@
~ B 0 1:1 -
~ BB=
O O O c=- @
33
fi g. 5. TrIgger (o nlrols. connec tors , and tndrce tore.
+: Sweep can be triggere d from the pos i tive-g oing
portion of a trigger signal.
Sweep c
an be triggered from the negati ve-going
porti on of a trigger sig nal ,
Co rrect SLOPE se tting is importan t in Ob taining a
disp lay when only a por tion of a cycle is bei ng disp layed .
31.
LEVEL - Selects the amplitude poinl on the trigger
s
ignal at wh ich the sw eep is triggered. It is usually
adjusted for the desired d ispla y after trigger SOURCE,
COUPLI NG and SLOPE have been sele cted .
10 415
/DM4 4 Oper ators @

32. SOUR CE- Determines the source of the t rigger
signa l coup led to the inpu t of the trigger ci rcuit
NORM : Trigger source is displa yed signal(s). It does
not indica te time relationship between CH 1 and CH 2
signa ls. However, stable triggering of non-time-relate d
signals usually can be obta ined by s ell ing VERT MODE to
AL T,
SOURC E to NORM and COU PLI NG to LF REJ.
Carefull y adjust LEVEL for a stable display
EXT:
Sign als connec ted to the EKt ern al Tri gge r Input
connec tors are used for trigge ring . External si gnals must
be time-related to the d isplaye d signal for a s tab led isplay .
It is useful wh en the
intern al signal istoo small or con tains
un desired s ignals that could cause unst ab le triggering It
is
use ful whe n opera ting in C HO P mode .
EXT -7- 10 (A
Trigge r circuit only) : Ext ernal trigge r
signal is atte nua ted by a factor of 10
CH 1: A
samp le of the signal ava ilable in Cha nnel l is
used as a trigger signal. CH 2 signal is unstab le if it is not
time-related.
CH 2: A
sample of the signal available in C hannel 2 is
used as a trigger sign al CH 1 signal is unstable if it is not
time-rela ted.
STARTS AFTER DELAY (8
T ri ~ ger ci rcui t onl y): 8
S
weep runs immediately after the delay li me selected by
the DE LAY· TIME POSITION con trol. When making
diff erential time measurements you must use this mode to
ob tain
valid measurements . On instruments e qui pped
with a DM44 you must use this mode to ob tain valid
measu rements when using the TIME or 1/T IME tuncuons.
LINE (A T rigger circuit only} : A sample of the power-
line frequency is used as a trigger signal. It is useful when
the input signal istime-related (mu ltipleo r submul tiple} to
the
line frequency or when it is desirable to p rovide a
stable display ot a li ne-frequency com po nent in a comple x
wavefo rm. 33.
Ede maI Trigger I npu ts- Input connectors for ex-
ternal trigger signals
@475/DM44
Op erators 11
Fig. 6. Horizontal. c, lIb. 't or , a nd power cn ntrota, co nnectors.
' nd in
dic, lo.s .
HORIZONTAL , CALIBRATOR , AND
POWER
34a. A AND B TI ME/ DIV AND DE LAY TIME- A
TIME /DIV switch (clear plastic skirt) selects the sweep
rate of the A Sweep circuit for A sweeocmvcce rauon and
selects the
basic delay time (to be used by the DEL AY-
TIME POS
ITION control ) for delayed sweep opera tion B
T1MEl DIV
swttcn ( pull out and e ota te to un tock }sel ects the
sweep rate lor the B Sweep circuit for delayed sweep
operation only. A VAR control must be in the calibrated
detent for calib rated A Sweep rates. When both TIME /DIV
swi tches are fully counterclockwise to the X-Y position ,
the
horizontal (X-axis) display is the CH 1 input.
35. FINE/P OS IT ION - Positions the display horizontal-
ly for A sweep and 8 Sweep
34b. DM44 A AND B T IME /D IV AND D ELA Y TIM E-
The
con trols operate in the same manner as 37a above.
The A TIME/DIV
switc h also contro ls the TIME lamps and
dec imal po int locat ion when the DM44 is in the TIM E
or 1
/TIME MODE .
36.
Xl0 MAG- Increases displayed s weep rate by a
fac
tor of 10. It extends fastest sweep rate to 1
nanosecond /division, The magni fied s weep is the center
division of the u nmagnified displ ay (0.5 division either side
of the center gr aticule line}.
42
34
0 0
39
-;;0
38 @
•
® l ~
•
0IiQ
0
0
0@@
12 475/DM44
Op erat ors @