Tektronix 7T11 User manual

in CUMN
Ι Ν E5
Τ ' F R U C - Γ 10 Ν
υ 1 Α Ν υΑ
L
s~
c °ε
P-0 .-ti

(
ρ
!
μ
9
.-
Ρ
4
ε
ε

ι
- ι 3-
ίί
Serial Nu mber
ι 2 F3
Te k t r onix, Inc . 0 Ρ . Ο . Box 500
"
B eaverton, Oregon 97005
"
Ph on e 644-0161
"
Cables : Te
k tronix
070-0986-00

570

WARRANTY
All Tektronix instruments are warranted
against defective materials and
workman
s
h
p
for one year .
Any
questions with
respect
to the war-
ranty
men6
ο ne
d
above should
be taken up
with your
Tektronix
Field Engineer .
Tektronix

repair

and

replacement-
part
ser ν ice i s geared
directly t ο f h
e field, there-
fore α !!
requests for repairs and
replace-
ment
parts should
be directed to the Tek-
tronix Field Office or
representative in your
area
. This procedure
will assure you the
fastest
possible sor ν ico
.
Ρ
!e ase inc! υ cl e the
instrument Type and
Serial or Model Num-
ber with
all requests for
parts or service .
Specifications
and price change privi-
leges reserved .
C σ
pyrigh
t , 'P) 1970 6
by Tektronix, Inc .,
Bo σν er t υ
n,
Oregon . Printed
in th e Uni t ed
States
of America . All rights
reserved .
Contents of this publication
may not be
reproduced in any form
without permission
of the
copyright owner .

S
ECTION 1

SPECIFICATION
TA BLE O F CO
NT EN TS
General Information

1-1
Instrument F eatures

1-1
E lectrical Characteristics

1-1
M echanical Characteristics

1-4
S ECTION 2

OPERATING INSTRUCTIONS
General Information

2-1
Installing the

7T11

2-1
ΤΙΜΕ /DIV Rea d out

2-2
Controls and Connectors

2-3
F irst-Time O p eration

2-4
Setu p Information

2-5
A d justing SWEEPCAL

2-5
Observing α F astrise P ulse

2-6
Triggering Consid erations

2-7
Trigger R ate

2-8
SWEEP RANGE Control

2-8
ΤΙΜΕ /DIV Settings

2-9
TIME POSITION Control

2-9
SCAN Control

2-10
T RIG
LEVEL
and
STABILITY Controls

2-10
Trigger
P
ushbutton
Switches

2-11
PULSE O UT Connector

2-11
U se of
R eal Time M od e

2-11
U sing the

7M11
Delay L ine

2-11
SECTION 3

CIRCUIT DESCRIPTION
T HEORY OF O PERATION
P
age
R eal-Time Sam p ling Theory

3-1
General

3-1
Staircase R am p 3-2
Lead Time

3-3
Sam p les/Division

3-3
Summary

3-3
Add itional R eal-Time Circuits

3-4
Controls Affecting Timing and Delay

3-5
Im p ortant W aveforms

3-6
Se q uential Sam p ling Theory

3-9
Ad d itional Circuits R e q uire d
3-9
Constructing The
Dis p
lay

3-11
W aveform R elationshi p s

3-11
F actors Affecting Dot Density

3-13
B lanking Circuits

3-14
U navoi d able Delay

3-15

TA
BLEO F CO NT EN TS
(co n t)
R
and om
Sam p ling T h eory

3-16
Intro d uction

3-16
R
and
om B loc k Diagram

3-16
R and om
O p eration

3-18
W aveform R elations h i p s

3-18
CI R C UIT A N A L YSIS
R elations h i p to V ertical U nit

3-20
Triggering Circuits

3-22
Internal Triggering

3-22
E
xternal Triggering

3-23
Trigger Slo p e Am p lifier

3-24
Trigger ( Χ 10) Am p lifier

3-24
Sc h mitt Trigger

3-24
HF SY N C

3-26
Arming and Outp
ut Tunnel Dio d es

3-26
Out p ut
Tunnel Diode Circuits

3-28
R eal an d
E q uivalent-Time L ogic

3-29
Start
M ultivibrator

3-29
ΤΤΗ Circuit

3-30
H orizontal Am p lifier

3-33
R eal-Time M ultivibrator

3-34
H orizontal M emory

3-35
Out put Am p lifiers

3-35
H
ol
d -off M ultivibrator (H O MV)

3-35
Slewing R am p 3-39
Strobe Drivers

3-41
Slow R am p Generator

3-41
Slow R am p Inverter and Time P osition Am p 3-43
Dot P osition M emory

3-44
R atemeter

3-45
R atemeter Start Correction Circuits

3-47
Timing Switc h es

3-47
R ea d out L ogic

3-48
S E CTIO N 4

M AI N T
EN
A
N
C
E
P reventive M aintenance

4-1
Troubles h ooting

4-1
Transistor and IC P in Arrangement

4-3
7T11 Troubles h
ooting P rocedure

4-5
Sol d
ering Tec h ni q ues

4-7
Com p onent R e p lacement

4-7
Circuit Board s

4-8
P in Soc k ets and Connectors

4-8
Tunnel Dio de C R 28

4-8
Switc h Rep lacement

4-9
Instrument R ep ac k aging

4-11
Circuit B oard Connections and Com p onent
L ocations

4-12 to 4-18

TA BLE O F CO N T EN TS (co n t)
S E CTIO N 5

PERF O RM A NCEC HE CK /CA L I BR ATIO N
Introduction

5-1
Test Eq ui p ment R e q uire d 5-1
Sh ort F orm P roce d ure

5-2
Calibration an d P erformance C h eck 5-4
A d j ust +10 V olts

5-7
C h ec k Manual Scan and Ad j ust Swee p
Cal and P osition

5-7
Timing Accuracy

5-7
Time P osition R ange

5-9
A d j ust Timing

5-9
A d j ust R an d om Timing

5-11
A d j ust Trig L evel

5-12
A d j ust Stability

5-12
A d j ust E xternal Trigger Zero

5-13
A d j ust Ν F Sync

5-13
A d j ust Out p ut B ias

5-14
C heck Triggering

5-15
C heck Dis p lay J itter

5-16
C heck P ulse Out into 50 St

5-19
C heck Trigger K ic k out

5-19
Trigger
H
oldoff

5-20
Strobe K ic kback into Trigger

5-20
M inimum Trigger R ate in R and om

5-21
R ep etition Scan R ate

5-21
Swee p OutR ange

5-21
E xternal In p ut

5-21
S E CTIO N 6

ELE CT R ICA L P A R TS L IST
Abbreviations and Symbols
P arts Or d ering Information
In d ex of E lectrical P arts L ist
E lectrical P arts L ist
SECTION 7

DIAG R AM S AN D ME CH A N ICA L P A RTS I LLU ST R ATIO N S
Diagrams
M ech anical P arts Illustrations
Accessories
R e pac k aging Instructions
S E CTIO N 8

ME C H A NICA L P A R
TS L IST
CH A N G E I N F O RM ATIO N
M ech anical P
arts
L
ist Information
In dex of
M
ech anical P arts Illustrations
M
ec h anical
P
arts L ist
Abbreviations and symbols use d in t h
is manual are based on or
ta ken d irectly from IEEE Stand ar d 260 "Stan d
ar d Symbols for
U nits", MIL-STD-12B and ot her stan d ar d s of t h e electronics
in d ustry . C
h ange information, if any, is locate d at t h e rear of t h is
manual .

Fig . 1-1 .

M1 Sampling Sweep Unit .

S
E
CTIO N 1
SPECIFICATION
Ch ange information, if any, affecting t h is sectio n will be
fo u nd at t h e
rear
of t h e
manual .
General Information

free of trigger j itter or double triggering, even
at low
trigger
T he

7T11 Sam p ling un it is designe d for use in Te k tro n ix

re p
etitio n rates or w h en using α sq uare wave as t he i n put
7000-series

oscillosco p es .

Several

p lug-in

combinations,

trigger signal . Α recovery time con trol is not n eeded .
i n clu d i n gα 7T1 1, are sh ow n in F ig . 1-2 . Α 7511 must be in
t h e compartment to t he left of, and ad j acent to, t he com-
pa r tment in w h ic h t he 7 Τ 11 is operate d . T h erefore, two

Selecting ΕΧΤ HF SY NC p ermits using fr eq uencies of 1
GH z to ap pr oximately 12 GH z as t h e trigger i np ut source .
7T1 11's are not used in t he same mainframe .

W
it h HF SY N C selecte d , the signal connecte d to t he T R IG
I NPU T connector is route d to αb uilt-in synch ronizer, thus
In F ig . 1-2 Α t h e 7 Τ 11 is s h ow n in t he " Α " H orizontal

p
ermitting Χ band signals to be viewe d .
com p artme n t of t he oscillosco pe . T he V ertical M od e and
H orizo n tal M ode p us h button s, provi d ing useful presenta-

Excelle nt swee p li n earity is p rovided w hen using t he
tions, are d esignate d for p lug-in configurations Α , Β , and C .

7 Τ 11 .

The

timi ng

circuitry

in

t h e

7 Τ 11

uses α time
F or t he configuratio n of F ig . 1-2 Α , fo u r combinations are
meas u reme n t rat h er t han α time p rogramming p rocess for
s h own . P lug-in arra n gements ot h er t h an t h ose sh own i n F ig .

horizontal sam p le positio n ing on all e q uivalent-time swee p
1-2 are p ossible .

r anges . Duri ng both ran d om and Seq uential op eration t he
h o r izo n tal p ositio n of t he d ot on t h e screen is d etermine d
_

An alte r nate to t h e con figuration s h own in F ig . 11-213 is

by measuring the time interval b etween strobe and trigger .
wit h t h e "LEF T" or " Β" or both of t h ese mainframe com-

This met hod results in improve d timing linea r ity and α
empty . T h e 7 Μ 11 may be use d in any available

re d uction in d is p lay j itter . T he accuracy of sweep timing
p artments
mai n frame com p a r tment o r o p erate d out of t h e main frame .

and
linearity ma ke it unnecessary, d uri ng e q uivalent time
F or furt h er information, see t he O p erating I n structions

sam p li n g, to exclu de t h e swee p start from accuracy s p ecifi-
section of t h is ma n ual un d er the h eading of General

r ations .
O p erating I nformation .
Internal triggeri n g, or
a
ny of t h ree
modes of extern
al
triggering
can be
selecte d by using t he front panel
p us
hbuttons . Α Sc h mitt trigger circuit is used exce p t
w hen HF SY N C is selecte d . W it h ΕΧΤ 50 Ω i nput
selecte d , t h e Sch mitt ci r cuit p rovi d es j itter free triggering
from in p ut trigger signals from DC to 1 G H z . T he dis p lay is
Α
C h aracteristics
Instrument F eatures

T h e followi ng c h aracteristics apply over an ambient tem-
p erature range of 0 ° C to +50 ° C at altitu d es up to 15,000
T h e 7 Τ 11 feat u res α wide range of swee p rates using

feet an d after α five-mi n ute warm u p, p roviding t he instru-
real-ti m e and e q uivalent-ti m e sam p ling . Conce n tric switc h es

°C and
select t h e sweep range and time p osition r ange in d ifferent

me nt was calibrated at α tem p erature b etwee n +20
+30 ° C . D u ring non-operation, donot su bj ect t he 7 Τ 11 to
com b i n atio n s for t h e time/div desired . On eq uivalent time

altitudes a b ove 50,000 f eet or to tem p eratures below
ranges, eit h er se quen tial or ra nd om sam p ling is availa b le .

_
ς
5°C .
U se of random sam p li ng p ermits d is p lay of t he lea d ing e d ge
of fast-rise i n p ut signals wit h ou t t h e use of α signal d elay
line (suc h as t he 7M1 1) or α p retrigger p ulse from t h e sig n al

ELE CT R ICA LC HA R ACT ER ISTICS
source .
Ch aracte r istic

P erforma n ce R e qu i r eme n t
ΤΙΜΕ /DI V
S WEEP RAT ES
7 Τ 11
Cali b rate d from 5 ms/ d iv to 10
p s/div, selectable
in
α
1, 2,
5
se-
q uen ce,
using
S
WEEP R A N G Ea nd
ΤΙΜΕ /DI V co n trols .

Specification-7T11
E q uivalent Time
ΙΑ )
ELE CT R ICA L C HA R ACT ER ISTICS (cont)

ELE CT RICA L C H A R ACT ER ISTICS (cont)
C h aracteristic

Ι

Performan
ce R
e q uirement

C h aracteristic

I

P erformance R equiremen t
Accuracy
R eal Time
L eft R ig h t
b la nk
S WEEP
R AT E S (cont)

S WEEP R AT E S (cont)
5μ s/ d iv to 10 p s/ d iv using t he 50
μ s to 50
n
s
Time P
osition
R
anges .
W
it
h in
3% ο .
7S11
Ι
7S11
Ι
7 Τ 11
Ι
7 Μ 11
7 Α -- Ι 7S11 Ι 7 Τ 11 Ι 7B--
On 5 ms
5 ms/ d iv to .1 μ s/ d iv usi ng t he 50

TIME POS
ms to .5 ms Time P ositio n R a n ges .

RNG
Plug-in
Co n fig u ratio n
7S11 Ι 7S11 Ι 7Τ 11
VER TICA L
M
OD
E
Accuracy
On 50 ms
TIME POS
RNG
Ι = Η ~ Η
ΓΙ L Ι 1~1
Fig . 1- 2 . Several plug-i n con fig u ratio n s usi ng t h e 7711 a nd α 7000-series oscillosco pe .
W it h in 3% ο , beginning 250 μ s after
un delaye d sweep start .
W it h in 3% ο , beginning
25 μ
s after
und elaye d swee p start
.
M ai n frame Switching
HOR IZO N TA L M OD E
LEF T
A L
T ADD CHO P R IG H T 11

Α

A L T C H O PΒ
Χ
Γ
~-
Η
Ι
Η

ΕΧΤ HF SY N C
*Sinewave
Triggering
C h aracteristic

Ι

Performance R eq uirement

C h a r acteristic

I

Perfo r mance R e qu iremen t
VA R IA BLE
( ΤΙΜΕ /DI V )
R ange
Input R esistance
ΕΧΤ 50 Ω
ΕΧΤ 1 ΜΩ
I n ternal
Specification-7T11
ELE CT R ICA LC H A R ACT ER ISTICS (cont)

ELE CT R ICA L CH A R ACT ER ISTICS (cont)
On 0 .5 ms
TIME POS
RN G
Sensitivity
R an ge
E xternal
Χ 1 Trig
Amp
Χ 10 Trig
Amp
50 Ω I n pu t
Sensitivity
R
a
n
ge
Χ 1
Trig
Am
p
Χ
10 Trig
Am
p
Safe
Overload
REV . Β , S
EP T .
1977
S WEEP R AT E S (cont)

T R IGG ER I NG (co n t)
W it h in 3 ° / ο , begi nn ing 2 .5, μ s after
undelayed sweep start, or after 500
ns from start of displaye d
portion
of sweep . Does not
inclu
de 100
ns/
div an d 200 ns/ d iv
p ositions
.
E xte n
ds
fastest sweep rate to at
least 4 ps/ d iv . P ermits increasing
t h e spee d of all sweep rates to at
least 2 .5 times t
he
calibrate
dsp ee d .
T R IGG ER I NG
50 Ω with i n 10% .
1 ΜΩ wit h i n 5% .
1 ΜΩ wit h in 5% .
1
ΜΩ
In
p
ut
HFSY N
C
I n
put
Safe
Overload
Display
J itter
Sensitivity
R a n ge
Χ 1 T r ig
Am
p
Χ 10 Trig
Am p
Safe
Overload
Sensitivity
R ange
125
m V
to
1 V Ρ - Ρ at vertical in-

50
Ω
a
n
d
1 ΜΩ
pu
t (5
kH z
to
500 MHz) .

Tr i ggering
12 .5 m V to 1 V Ρ - Ρ at vertical in-
p u t (5 kH z to 50 MHz) .
*NOTE
Trigger circuits will operate to DC
with pulse triggering, except for HF
SY NC .
12 .5 mV to 2 V ( Ρ - Ρ ), DC to 1 G H z .
1 .25 mV to 2 V ( Ρ - Ρ ), 1 kH z to 50
MHz .
2 V (DC
+peak
AC) .
Sequ ential Mode
R and omMo d e
HF SY NC
R an d om or
Se qu ential
Mode
12 .5 mV to2 V (P-P), DCto100
MH z .
1 .25 m V to 2 V (P-P), 1 kH z to 50
MH z .
100 V DC or 100 V (P-P) to 1 kH z ;
derate d6 d B /octave above 1 kH z to
5 V (P-P) .
10 m V to 500 m V (pea k -pea k )
at
1
G H z ; 200 m V to 500 mV (pea k -
p ea k ) at 12 .4 G H z .
2 V ( peak -pea k ) .
10 ps or less at fastest S WEEP
R A N G
E p
osition (f u lly CC W ) ; 0 .4
d ivisions or less at remaining six
positions of S
WEEP R AN
G
E ;
measureme
n
ts ma d
e
un
d er
o p ti-
mum
trigger con d itions .
30 p s or less at fastest S WEEP
RANGE
p
ositio n (f u lly CC W ) ; one
division or less at remaining six
p ositions of S WEEP R A N G E ;
meas u reme n ts made un d er opti-
m u m trigger con ditio n s .
20 p s or less wit h α12 .4 GH z, 200
m V ( p ea k -pea k ) signal ; measure d
under optimu m trigger conditions .

Specification-7T11
ELE CT R ICA L C
H A R ACT ER ISTICS (cont)

ELE CT R ICA L C H A R ACT ER ISTICS (cont)
C h a r acte r istic

Pe r formance R e q uirement

C h aracte r istic
_~

P erformance R e q uirement
PUL S
E
OU
T (i n to
50 Ω )
Am p litu de
R isetime
Trigge r K ic kout
M i n imum Trigge r
R ate in R AN DO M
M ode
Sca nR ate
REPETITIVE
SCA
N
Deflectio n F actor
S WEEP CA L
TR IGG ER I N G (co n
t)

H OR IZO N TA L D EFLE CTIO N SYST E
M
(cont)
Positive-goi n g p ulse of at least 400
mV .
2 .5 ns or
less .
±2
m
V or less into 50 Ω (except
HF SY N
C) .
100 Hz .
SL O W R A
MP
G
ENER ATO R
Conti n uously varia b le from less
t han 2
sweeps/sec :
to at least 40
sweeps/sec .
H O R IZO N TA
L D EFLECTIO N SYST EM
Pe r mits a d j ustment of
d eflection
factor fo r all 7000-se
r ies main-
frames .
EXT ERN A L I NPU T
In p
ut R esistance
Deflection Factor
Maximum In p ut
Voltage
S WEEP O UT
Dimensio n s
Heig h t
W i dth
Len gt h (incl ud i n g
fro n t p anel kn obs
an
d rea r co nn ecto r
)
Constructio n
Accessories
100 k Ω with i n 10% .
Contin uou
sly
varia b le from 10 V to
1
V/ d
iv .
100 V (DC +
peak AC)
.
+5
V to-5 V
ME C
H
A
N ICA L C H A R ACT ER ISTICS
-5 inc h es .
-2'/ α inc h es .
14'/2 i nch es .
Alumi nu m
alloy
ch assis wit h e p oxy
laminated
circuit boar d s . Front
panel is anod
ize d aluminum .
An illustrated list of t h e accesso r ies
su pp lied with t he 7 Τ 11 is at t he
end of t he M ec h a n ical Pa r ts L ist
p ullout p ages .

General I n formation
SECTION
2
OPERATING INSTRUCTIONS
C h ange information, if any, affecting t h is sectio n will be found at t he r ear of t he m anual .
T his section covers installation, first time o p eration,
function of front p anel controls and connectors, an d
general o p eration of t h e 7T 11 Sam p ling Swee p U nit .
T he 7 Τ 11 is intende d for use in the Te k tronix 7000-
series
oscillosco p es . U se of t h e 7T11 with α 7511 Sam p ling
U nit an d any of α variety of S-series Sa m p ling H ea d s
p rovi d es α sam p ling system a d a p table to α wide ra nge of
a pp lications .
R eal-time sam p ling is provi de d at t he t h ree slowest
sweep rate settings of t
he 7Τ 11
Swee
p R
ange
switc h .
Sampling is in
e q uivale n
t-time
for t he remaining four p
osi-
tions of t he Swee p
R ange switc h .
On
t h ese four ranges
eit
h
er se q
uential or ran d om e q uivalent-time sam p ling may
be selecte d .
T he 7 Τ 11 sweep
may be sync h ro n ize d using an internal
or external triggering source .
External signals from DC up
to a pp roximately 12 G H
z can be
use
d as t h e trigger source .
Α trigger am p lifier p rovi d ing Χ
10 a mp lification is available .
ΝΟΤΕ
Internal trigger
sig n
als are
not routed t h roug h t h e
trigger
source switc h es on t h e oscillosco p e due to t he
frequencies
involved and noise considerations . Selec-
tion
of t h e trigger source is made on t h e front panel
of
t
he
plug-ins .
7 Τ 11
F
ig . 2-1 . Con n ector J 641 (fixe d sh oe), provi d
i
ng intercon
n
ectio
n
b etwee n7 Τ 11 and 7511 for strobe a n d trigger sig n als .
I n stalling t he Ty p e

7T11 in t h e Oscillosco p e
T h e

7T11 is d esigne d to
dri ve t he h orizontal d eflection
plates of t h e oscillosco pe C
R T, an d
t
h erefore is installe d in
t he rig h t- h a nd com p artment of the oscillosco p e . Wh en only
one Ty p e

M1 and one 7511 are use d in α 7000-series
oscillosco p ep rovi d ing t w o vertical and two h orizo n tal com-
p artments, t h e

7T11 is inserte d in the left- h an d h orizontal
co
m partment and t he 7511 in t h e rig h t- han d vertical com-
p artment . T h is p rovides an interconnecting p at h between
t he

7T11 and
t he 7511 for strobe and trigger signals .
To
insert t h e

7T11 in to t he oscillosco p e com p artment,
align t he grooves along t he to p an d bottom of the p lug-in
wit h t h e up p er an d lower slide rails in t he oscillosco p e com-
partment . T he unit sli d es straig h t i n and self-loc k s itself i n
p lace . T hep lug-i n is remove d by pulling straig h t out on t he
p lastic button labele d 7T1 1 .
Triggering signals
travel between p lug-in units along 50
Ω coaxial or
stri
p lines
.
T h
ese signals travel between plug-in
units using
contacts on connector stri p s fastene d to t he

Mating t h e

7T11 to t he Oscillosco p e
sides of t h e plug-ins
.
Α
connector stri p is s h own in t he
ph otogra
p
h
of Fig . 2-1 . Since t he strobe p ulses also travel

T h e

7T11 h orizontal gain must be matc hed to t h eh ori-
between α

M1 an d α 7511 p
lug-i n t h roug h contacts on t he

zontal d eflection factor of t he CR T in t he oscillosco p e .
connector stri p s, t h ese units must
be locate d in a d j acent

H orizontal gain is set using t he Swee p Cal control (screw-
oscillosco p e com p artments .

d
river
a
d j ustment) locate d on t h e 7 Τ 11 front p anel . Α

O p erating
Instructions-7T11
met ho d of a d j usting t h e Swee p Cal is discusse d i n t he First

T he ΤΙΜΕ /DI V selected at t he

7T11 front p anel is dis-
Time Operation P roce d ure later in t h is section . Th is a d ju st-

p
laye don the C R T using t h e d igits 1, 2, or 5 followed by
ment must be reset eac h time t h e

7T11 is transferred be-

one or two zeros if re q uire d . T he ΤΙΜΕ /DI V rea d out d oes
tween oscillosco p es, an d w hen α co n si d erable ch ange in

not
use decimal
p
oints . T he d is p laye d d igits are followed by
am b ie n t tem p erature occurs .

t
he un
its-of-measure rea d out . W it h t he

7T11 t he units-of
ΤΙΜΕ /DI
V Readout

measure d is p laye d will be ms/div, μ s/ d iv, ns/ d iv or p s/ d iv . If
t
he VA R IA
BLE (CA L IN) switc h is in t h e out p osition t h e
T he

7T11 ΤΙΜΕ /DI V setting selecte d is dis p laye d near

symbol usedto indicate less t h an (G), is d is p layed p re-
t h e to p of t he C RT exce p t w hen t he

7T11 is used in α

ce d
ing
t he ΤΙΜΕ /DI V readout as α warning t h at the d is p la y
oscillosco pe without rea d out circuitry . T he h orizontal p osi-

is uncalibrate d . T h e intensity of t he rea d out is in d e p en d -
tion of t he rea d out on t h e CRT corres p ond s to t he h orizo n -

ently ad j ustable by α front p anel control
on
t he
oscillo-
tal p osition of t he oscillosco pe com p artment in use .

sco p e, w h ic h also p ermits t he rea d out to be switc hed off .
2-2
F ig . 2-2 . 7T 11 fro n t pa n el .

All controls re q uire
d for op eratio nof t he 7 Τ 11 are

ΤΙΜΕ /DI V Selects calibrate d time/ d ivision set-
locate d on t h e
front panel of t h e unit (see F ig . 2-2) .

Switc h tings from 10 p s/ d iv to 5 ms/ d iv, in
Controls, p ush buttons,
an d co n nectors associate d wit h trig-

27 steps, in α 1, 2, 5 sequ ence .
gering are located along
t he rig h t side of t he front p anel a
n
d
are inclu d ed in an
area outlined in gree n . T he SCA
N
con-

V A R IA BLE (CA L

Wh en in t he out p osition, rotati ng
trol, p ush
buttons, an d an external in p ut con nector are
i nα

IN)
Control

t he

V A R IA BLE

control

p ermits
grey
outlined area at t he lower left of t
he p
a
n el . T he

c han ging time p er division from t he
remain
d er of t he front p a n el contains Swee
p circuit con-

calibrate d value selected by the
trols, switch es, a nd ad j ustments .

ΤΙΜΕ /DI V switch . Pus h k nob in
a nd release to activate ; t he k nob
moves outward from t he TIME/
Α brief description of the function or op
eration of t he

DI V co n trol w hen activate d .
front p anel con trols follows . M ore detaile d
information is
give n un d er General O p erating
Information .

TIME
P
OS
RN G

Time- p ositioning ranges from 50 ns
to
50 ms in seven d eca des are avail-
able . Time- p ositioning range avail
S WEEP Controlsand Connectors

a b le an d i nd icate d in the TIME POS
TIME
P OSITIO N and

Two concentric
controls p rovidi n g

RN G window is d etermine d by t
he
F I NE co n trols

coarse or fine control of
t he time

setti ng of t he S
WEEP

R A NGE
relations h ip b etween
triggeri n g and

switc h
.
T h
ein
d icate dr ange is
t he start of t h e C R T dis p
lay
. T h e

always ten times the
slowest time/
TIME P OSITIO N control permits

d iv of t
he
Swee pR
ange selected .
continuously variable ad j ustme n t of

SWEEPCA L

Α front p anel screw d river a d j ust-
d elay i n starti ng t he d is p lay, up to

Control

ment t hat ad j usts h orizontal gain to
t he amou n t indicate d in t h e TIME

matc h t he oscilloscope deflection
P OS RN G window . T heF I
NE
con-

factor . A dj usted w henswitch ing
trol h as only about 1°/ ο of t h e effect

7 Τ 11

from

one

oscilloscope

to
of t h e TIME P OSITIO N co n trol,

anot h er .
and is p articularly useful at TIME/
DI V settings of h ig h magnificatio
n .

P
OSITIO N

Α front p anel screw d river a d j ust-
Co
n trol

ment to p osition t he dis p lay h ori-
R A N DOM Selects
R
an
d
om Sam
p li n g mode of

zontally
on
t he C RT of t he oscillo-
Push butto n

op eratio
n
. Does not
function i n t he

sco p e .
t h ree slowest
(real-time) Swee p
R
anges .
P ermits the dis p lay of t h e
i n p u t signal p rior to t he triggering
p oint wit h out use of α delay li ne or

SWEEPOU T

P i n j ack p rovi d ing an- , out p ut volt-
pretrigge r .

J ac k age p roportio n al to t h e d is p lay .
W it han out put resistance of 10 ΚΩ
an out p ut of one volt for each divi-
sion of d isplay is provided .
SE Q
UEN TIA L Selects Se q uential Sam
p ling mode
Push button

of operation . Does
n
ot
function in
t h e t h ree slowest
(real-time) Sweep

SCAN Controls
R an ges .
P ermits e q uivale n t-time
o p eration

at

lower

trigger re p e-

V ariable SCA N

Pr ovi des

an

internal

voltage for
tition rates t h an does t he R andom

Control

a d j usting t h e scan rate in t he REP
mo de .

mo d e, or for ma n ually sca n ning t h e
display i n t he
MAN mo
d e . Also
S WEEP R A
N
G
E

Selects t h e range of operation of

use d to set t h e h orizon tal gain using
Switc
h

t he ΤΙΜΕ /DI V switc h an d in d icates

t he S WEEP CA L control . Serves as
t he correspon d ing time p
osition

α va r iable attenuator in t he
range (TIME
P
OS RNG) .
P ermits α

E XT ERN A L I NPU T mode .
choice of any of
nine
ΤΙΜΕ /DI
V
settings at each of the seve n p osi-

REP P us hb utto n

P rovi d es re p etitive scanning of t he
tio n s of t he S WEEP R
AN
G
E

d isplay . Sca n rate is a d j uste d using
S W ITC H . T he S WEEP R AN G
E
con-

t he variable SCA N control . It d oes
O p erati n g Instructions-7T11
FR ON T P A NEL CO
N T R O L S AND

trol is concentric wit h t h e
TIME/
CO
NNE CTO RS

DI V an d V A R(CA LIN)
controls
.
2- 3

Operating Instructions-7T11
REP Pu s h
button

not fu nction in t he t h ree slowest

controls are u se d to obtain α stable
(cont)

(real-time) Swee pR anges .

d is p lay
wit h trigger signals above
a pp roximately 1 G H z .
MAN P us h button

Provides man u al o p eration of t
he
scan

function

using

t he variable

ΕΧΤ TR
IG
I NPU T

Α 3 mm connector locate d near the
SCA N control . Does not function

Connector

lower rig h t p ortion of t he front
in t he t h ree slowest (real-time)

p
anel and use d for intro d ucing an
S w ee p R anges .

external triggering signal to the
7T1 1 .
ΕΧΤ I N PU T

Allows scanning t he d is p
lay using
P us h button

an external signal . In th is mo d
e
of

PUL S E O
U
T

Α B S M connector p rovi d ing α posi-
o p eration, t he variable SCA N con-

Connector

tive p ulse corres p on d ing to t he
trol serves as α variable attenuator .

firing of t he trigger circuit .
E xternal In p ut

Α p in j ac k (in put resistance of 100
J ac k

k Ω ) p rovi d ing an in put facility for
externally scanning the d is p lay .
W it h t he SCA N control fully C W α
one volt input is neede d for eac h
division of d is p lay .
Triggering Controls

Wh en s h i pp e d from t he factory, t he 7 Τ 11 Sam p ling
S w ee p U nit h as been calibrate d to meet t he s p ecificatio n s
SL
O PE

Selects

t h ep ositive-going

(+)

or

liste d in Sectio n 1 and is rea d y to be used wit h α Te k tronix
Pu
s
hb
uttons

negative-going (-) slo pe of t he trig-

7000-series oscillosco pe .
gering signal .
TR IG LEVEL

Determines t he am p litu de level on
Control

t he triggering waveform w h ere trig-
gering is to occur . Also serves as α
fine sync h ronizing a d j ustment in
t he HF SY N C mode . T he T R IG
LEV E L control is concentric wit h
t
he STA
B
ILITY
control
.
STA B
I
L
ITY

Ad j usts t he wid t h of t
he trigger
Control

h ysteresis . Also serves as α
coarse
sync a d j ustment in t h e HF SY N C
mo d e .
T R IG AMP

Select Χ 1 or Χ 10 am p
lification of
P
ushbuttons

t he trigger signal
.
ΙΝΤ P us hbutton

Selects internal triggering
for op era-
tion with sam p ling h ea d s t
h
at
p ro-
vi de α trigger p ic k off .
ΕΧΤ 50 Ω

Selects external,
DC-cou p le d ,
low
Pushbutton

im p e d ance trigger op
eration at t he
common trigger input
connector .
ΕΧΤ
1
ΜΩ

Selects external, DC-cou p le d ,
h ig h
P
us
h button

im p e d ance trigger o p eration at
t he
common trigger in
p
ut
connector .
ΕΧΤ HF S YN C

Selects external, AC-cou p le
d (1 ΜΩ
P us hbu tton

to groun d ) HF SY
N
C op
eration .
In
t h is mo de of
trigger op eration, t he
STA B I L ITY

an d

T R IG

L E VEL

F ig . 2-3 . E qu i pm e n t set u p u se d d uring first time o p eration .
2- 4
General
FIRST-TIME O PER ATIO N
The following ste p s d emonstrate the basic op eration of
t he controls of t he
7T1 1 .
It is recommen
d
e d t h
at
t h is p ro-
ce dure be followe d com p letely for familiarization with t h e
instrument . O p eration of t he oscillosco
p e an
d vertical p lug-
in unit (Sam p ling U nit) is d escribe d in t h e instruction
manuals for t h ese units . T he e q ui p ment
set-up
use d d uring
t he following p roce d ure is s h own in F ig . 2-3 .

Setup Information

7T11 (cont)
1 . I n sert
α 7511 Sam p ling Un it with α Ty pe S-2
Sampling H ead in
t h
e
left vertical com p artme n t of the 7504

REP p us hbutton

P ushe d in
oscilloscope .

STA B I
L
ITY control

Fu lly CC W
T R
IG
LEVEL con trol

M i d position
SL O PE p us h butto n (+) p us h ed i n
NOTE

T R IG AMP p ushbutton

X10 p us hed in
ΕΧΤ 50 Ω triggering

P ushed i n
An y Tek tronix 7000-series oscilloscope may be su b-

pus hbutton
stit
u
te
d for t h e 7504 .
Only
t he plug-ins listed in steps
2 and 3 a r e actually n ee d ed to p erform th is F i r st
Time O pe r atio n but th e use of P lug-i ns listed in ste p s

Ty p e 284
1 and 4 is illust r ated late r in t h is sectio
n
unde
r
t
he

Sq
uare W ave Am p
litu
de

1 .0
V position
h eadi ng of GeneralOperating Info
r
mation
.

P eriod

1
As
M ode

Sq uare W ave or Sine
2 . I n sert

α

7511

Sampling

Un it with

α Ty pe S-1

W
ave O u tput
Lead
Time

75 ns
Sam p li n g H ea d in t h e r ig h t vertical compartment of t
h
e
oscillosco p e .

NOTE
Type
284 instruments h aving serial n u mbe r s prior to
3 . I n se r tα

7T11 Sam p ling Swee p Un it i n t he " Α " h ori-

S
N
8030236 req u ire installation of F ield M odifica
zon tal p lug-in com p artme n t .

tion K it, Tek tronix P
art No . 040-0487-01 in o r der to
ob tain α 75 ns trigger lea d time .
4 . I n se r tα7 Μ 11 50 Ω Delay L ine in the Β h orizontal
com p artment . T h is p lug-in may be used on t he bench alo n g-
si d e of the oscillosco pe
instea d of in the p l u g-i n com p art-
ment si n ce t h e only connectio
n s re q uired are to t h e 7M11
fro n t pan el .
5 . Set t h econt r ols as
follows :
7504
V
ertical
M
ode

R ig h t
H orizontal M ode

Α
R ea d out

M i d position
Co
n trol Ι lium

H ig h
I n tensity

F ully CC W
Ad j
ust t
he F ocus,
Intensity, an d DC Offset controls fo r
7511

α dis p lay similar to
t h at sh ow n in F ig . 2-4 . R otate t he
SCA N control
slowly from o ne ext r eme to t h e ot h er an d
+
UP p us h butto n

P ushe d in

note t h at cloc
k wise rotatio n i n creases t he sca n rate a nd
DC Offset control

M i d position

re
du ces t h e dot density . R eturn t he SCA N cont r ol to its
m V olt/Div switc h 200

mid p ositio n . P ush in and release t h e V A R IA BLE (CA L IN)
Normal pus hb utto n

P ushe d in

control an d note t h at t he less-t han symbol (<) is d is p layed
on t h e CR T j ust to the left of the 500 ns r ea d out . R otate
t he VA R IA BLE co n trol from its fully CC W position an d
7T11

note t h at - cloc kwise rotation results in an increasing mag
n i-
ΤΙΜΕ P OSITIO N controls

Fu lly cloc k wise

ficatio n of t he d is p lay or α re d uction in actual
time p er
S E Q UEN TIA L pushbutton

P ushe d in

d ivision . R etur n the VAR IA BLE control to its
fully CC W
TIME P OSRN G

5
μ
s

p
osition a nd pus h it i n to t he CA L p osition
.
ΤΙΜΕ /DI V

.5 μ s/Div
(500 n s readout)

Adjusting S
WEEP CA L
VA R IA BL E (CA L IN)

Pu s hed in
control

Pu s h t
h
e MAN
SCA N pushbutton in and observe th at
SCA N control

M
idpositio
n

t he pu s hbutton

lig h ts .

Turn

t he SCA N con trol fully
REV . Β , S EPT . 1977
O p e r ating Instructions-7T1
1
T u rn
on
p
ower an d allow
t he e
q ui p ment to
warmu
p for
5 minutes . Connect α 50 Ω coaxial cable h avi n gα 5 ns
sig n al d elay a n d G R 874 con n ectors between the Ty p e 284
Sq ua r e W ave or Si n e W ave O u tp u tco n nector and t he input
conn ecto r of t h e Ty p e S-1 Sam p ling H ea d .
Connect t he Trigger Out p ut con
nector of t he Type 284
to t he 7 Τ 11 T R IG I NPU T con
nector t h roug hα 50 Ω
coaxial cable wit h α 2 ns signal d elay an d BN C connectors
.
Α 3 mm male to BN C ad apter (Tek tro n ix
P
art No .
015-1018-00), i n clu de d as α stan d ar d accessory with t he
7T1 1,
must be conn ecte d to t he 3 mm TR IG I NPU T con-
nector on
t he 7T1 1 .
2-5

Operating Instructions-7 Τ 11
EMNSHIMENE
MENNEEMENE
F ig . 2-4 . Se q uential equivalent-time sa m p li n g display of 1 μ s, 1 V
s qu are-wa ve o ut p ut of t h e Ty p e 284 .
during Sequential eq uivalent-time sam p ling . T hese met hod s
p
rovi d
e α
m ean s of getting t h e t r ace started before t he verti-
cal
signal r
each es t he CRT vertica l d eflectio n p lates . T h ese
m et h od s are as follows :
{ α } The pat hof
the vertical signal t h at m ust travel from
t h e signal
so u rce to t he Sam p li ng H ead in put can b e
lengt h ene d w h ile the d istance travele dby t h e trigge r i n g
signal
is k e p t as s hort as possible . T h is m et hod , u sing α
7 Μ 11
50
Ω
Delay L ine, is d iscusse d later in t h is section
u
nder t h e h ea d ing of General O p erating Information .
(b) T he m eth od use d d uri ng F irst-Time Operation is to
use α sig n al sou rce, such as t he
Type
284, t h at p rovi des α
signal for triggering slig h tly before it d elivers
an
out p ut
pulse to the
Sam p ling Hea d i np ut . Α p retr έ gger Lea d T ime
of either 5 ns or 75 π s can be selecte d at t he Type 284
fron t
panel .
cou n tercloc k wise . Α s pot s h ould be observed at the left

Change
the settings on the followi n g controls :
e dge of t he graticule . Rotate the SCA N control to its f u lly
C W position . T he spot should have move d exactly te n d i υ i-

Typ e 284
sio n s to t h e rig h t
of
its previous position . Use α s m all screw-

Mode
switch

PUL S E O UT PU T
d rive r to a d j ust the SWEEPCA L on th e 7 Τ 11 fro n t p an el
for
te
n d ivisions of m ovement w h en t he SCA N control is
turne d from one extreme
to
t he ot h er . T h is ad j u stment

7511
s hould b e ma de w h enever t hep lug-i n is switched to α

mV /Div

50 mV /Div
different oscillosco pe . T h is a d j ustment s h ou l dbe chec ke d
occasionally even if the
plug-in
remains wit
h
t
he
same
oscillosco p e .

7T11
TIME P OS R NG

50 ns
T he P OSITIO N control on t he 7 Τ 11 fron t p anel is

ΤΙΜΕ /DI V
5 π s
ad j uste d withα screw d river so t he spot ap p ears at t h e left
graticule e dge wit h t he SCAN cont r ol fully CC W . R eturn
t he SCA N to re p etitive by pus h i ng the RE P pus hbu tton and

Disconnect the coaxial cab
le from the Ty p e 284 Square
set t he SCA N control it its ap p roximate midposition .

Wave or Sine Wave Out p ut co n nector and reconnect it to
t h e Ty p e 284 P
u lse O u t p ut co n nector . C h eck t hat t h e rea d -
out d is p l aye d
on
t he C RT
is 5 ns, and t h at t he Ty pe 284
Observing αF ast- R ise Pul se

Lead Time switch is set to the 75 n sp osition . V ertically
center t he d is p lay
usi
ng
t he 7511 DC Offset control .
One
m
et
hod of
observing
t he lea d ing ed ge of α f ast-rise
p u lse is to use α slow e n ough s w eepso t h at t hep ulse fol
lowing
t
he one pro d ucing trigge r ing is disp laye d . E it h er

W
it h t he TIME P OSIT I ON co n trols fu lly CW
the
lea d ing
Internal
or
E xternal triggering can b e used, B y u sing t he

edge of
t he out p ut pulse of t h e Ty pe 284 s h ouldbe visible
TIME P OSITION cont rol to move t he d is playe d p ulse near

as s h own
in t
he
typical d is p lay of F ig . 2-5 Α . F ig . 2-5 Α
to t h e left graticule e dge and turn ing the ΤΙΜΕ /DI V s w itc h

s h
ows that alt h oug h t he Ty p e 284 is s u pplying α trigger 75
clock wise to α setti n g provi d ing h igh m agn ificatio n , satis-

ns before
t
h
e
P
ulse O u t pu t signal, the signal is d is p laye d
factory results can be obtai n ed if the in put signal h as the

on ly 7 or
8 ns afte rt h e trace starts . If t h e 3 ns d ifference in
prop er characteristics . The i nput sig n al re p etition rate must

travel ti m e
throug h t h e coaxial cables delivering the vertical
b e constant ; oth e r wise j itter or α meani n gless d isplay will

input and
trigger i n p ut signals is consid ered, t he actual
result . Also, if t
h
e interval between pulses is excessively

effective trigger lea
d time is a p p roximately 78 ns . In Fig .
long compare d to the time
interval
of i n terest,
α suitable

2-5 Α the lea d time is
only
7or 8 ns
more t han t he m i n i-
combi n ation of TIME P OS RN G an d ΤΙΜΕ /DI V will b e

mu m re q ui r ed to d isplay t he
in put sig n al lea d i ng e dge . T h e
u nattainab le .

location of the pu lse in F
ig . 2-5 Α is typical . F actors t h at
will affect t he horizontal position,
of t
h
e p ulse lea d ing edge
Two
ot h er met h ods of seeing before the trigge r ing p oint,

wit h res pect to the start of t he swee pare : slig h t d ifferences
without the li m itations of t he met hod above, a r e available

i n
t
he
L ea d Ti m e p r ovi d ed by different Type
284's, d iffe r-
2-6

Α
( Α ) Ty p ical dis p lay with TIME
P OSITIO N fully C W and 75
n
s
of
p retrigger .
(
Β )
E ffect
on
display of F ig . 2-5 Α of CC W moveme
n t of
TIME P OSITIO N co n trol .
ι i
ί
ι
ι ~ ιιιιι
NOOSE
IN
(C)
Same
set-up
as F ig . 2-5 Β exce p t
for
ad d
ition of 5 ns
le n gt h of coax to vertical sig n al pat h
.
F ig . 2-5 . Observi n g t h e leading e d ge of α
fastrise pu lse usi n g t h e
Triggering Consi d erations
Op
erating Instructions- 7T11
ences in t h e d elay wit h in d
ifferent 7T1 1's, and t he setting
of t he T R IG LEVEL
control .
R otate t he TIME
P OSITIO N and FI NE controls slowly
CC W and notice t h at t
hey increase d elay and t hereby cause
t h e d is p laye d p ulse to
move to t he left . U sing t he TIME
P OSITIO N controls,
set t he p ulse lea d ing edge one d ivision
from the left e d ge of t he
graticule as s h own in Fig . 2-5 Β .
Disconnect t he coaxial cable
from t he in p ut of t h e Ty pe
S-1 Sam p ling Hea d an d insert an a
dd itional 5 ns lengt h of
coaxial cable between t he
cable j ust d isconnected and the
Sam p ling Hea d in p ut . T
h
e a
dd itional 5 ns of d elay inserte d
in t he p at h of t h e in p ut
signal will cause t he p ulse to move
one d ivision (5 ns) to t he rig h t
as s h own in Fig . 2-5C . T h is
p rovi d es α means of p rovi d ing a dd itional lea dtime
an d also
α means of d etermining t he d elay cause d by α
lengt h of
cable .
Turn t h e ΤΙΜΕ /DI V switc h to t h
e
.2
ns/Div p osition
(200 p s rea d out on C R T) and use t he TIME
P OSITIO N
control to h orizontally p osition t he pulse
leading e d ge to
graticule center . Note t h at t he
FI NE control h as more
effect in moving t h e d is p lay as t he
ΤΙΜΕ /DI V control is set
to its more cloc k wise p ositions .
S p ecifie d risetime of t he Ty pe S-1 (350 ps) is too slo w
to accurately measure t h e Ty pe 284 outp ut p ulse risetime
(<70 ps) . If t h is risetime measurement is d esire d , use α
Ty pe S-4 Sampling Hea d w h ic h h as α risetime of less t han
25 p s . Consult t he instruction manual for t h is sam p ling
h ea d for more information on measuring fast-rise signals .
Turn t he oscillosco pe Intensity control fully counter-
cloc k wise an d p us h in t he
HF SY N
C p us
h
button .
T
h e
HF
SY NC p us hbutton will lig h t an d t h e Χ 10 T R IG AMP an d
(+) SL O PE lig h ts will go out . Wh en using HF SY N C, the
triggering slo p e and t he T R IG AMP controls h ave no effect .
R
otate t he S WEEP R A NG
E
control fully C W to w h ere
the TIME P OS RN G win d ow s h ows 50 ms . R eal-Time
sam p ling is p rovi de d at t h is setting of t he S WEEP R A N G E
control as well as at t he next two faster S WEEP R A N G E
settings . T he S E Q or R A N DO M p us hbuttons will not lig h t
on t h ese t h ree R eal-Time ranges . T h e SCA N controls are
also ino p erative on
R
eal-Time ranges and t h ese pushbuttons
will not lig h t .
G ENER A L O PER ATI NG I NF O RM
ATIO N
Wh en using Se q uential e q uivalent-time sam
p ling to
SEQUENTIAL eq u ivale n t-time mo
de .

observe α fast risetime p ulse, α p retrigger or external
d elay
2-7

Op
erating Instructions- 7T11
line is normally required . U se of α7
Μ 11 Delay L ine is

greatest
variation from t he minimum
h ol d off time s h own in
discussed later in t h is section .

Table
2-1 .
Internal triggering or any o n e of
t h ree mo d es of E xternal
triggering
can
be selecte d by
using four p us hb uttons on t he
7T11 front p an el . Triggering
signals are n ot route d t hroug h
t he pushbuttons . T
h
e
front p anel p us h buttons control ree d
relays locate d in t
he 50 Ω p at h p rovi ded for triggering
signals . (Triggering
controls on t h e oscilloscope mainframe
h ave no con trolling
effect .) T h is triggering system re d uces
pic ku p of unwanted
noise and loss of h ig h fre q uency com-
p onents of t he
trigger signals .
Internal
triggering of the

7T11 from t he sig
n al
app
lie d to
eit h er vertical
c h annel is availa b le . P us h ing in t he
ΙΝΤ p us h
button on t
he

7T11
will cause t h is button to lig
h
t .
T he ΙΝΤ
p us h button lig h ts on t h e 7511
t h at is s up plyi ng t he trig-
geri ng signal .
Triggering
R ate
Triggering
rate is limited b y h oldoff . T he
minimum trig-
ger h ol d
off time at eac h of t he seven available
time p osi-
tioning ranges (in d icate d in t h e TIME
P
OS
RN G window) is

SWEEP R ANG E Control
s
h own in Table 2-1 . T he TIME P OSRN G is determined
by

Swee p rate of t he dis p lay is co n trolle d by th ree
con-
t he
setting of t he S WEEP R A NG E control .

centric kn obs . T he outer, larger k nob (S WEEP R ANG E
control) controls the sweep range over w h ic h t he TIME/
DI V k nob may be switc he d . T he window on t he left of t he
TA BLE 2-1

ΤΙΜΕ /DI V kno b d isplays t h e TIME P OS RN G (time p osi-
tioning range) ; t h is num b er is always 10 times t h e slowest
M inim u m Trigger H oldoff

available ΤΙΜΕ /DI V of αp articular S WEEP R A
N
G
E
setti
n g .
T he selecte d ΤΙΜΕ /DI V is d is p laye d on t he CRT by t he
Indication
i n

M i n imum
Trigger

oscillosco pe if t h e oscillosco p e is p rovi de d with rea d out
TIME P OSRN
G

H oldoff
Time

ca
p
ability . T he V A R IA BLE con trol can p rovi de α minim u m
win d
ow

of 2 .5 to 1 magnification at any ΤΙΜΕ
/DI
V setting
.
At t
he
th ree slowest S WEEP R A N G E settings, sam
p ling is in R eal-
R Τ

50
ms

at least
2 ms

Time w h ile t h e remaining four
positions p rovide e q uivalent-
Ε

Ι

5
ms

at least
2 ms

time (ra n dom or se q
uential) sam p ling .
Α Μ
L

Ε

500 μ
s

at least
2 ms
50

s

at least 220 μ s

The ΤΙΜΕ /DI V settings available at eac h position of t
h
e
Ε Τ

μ

S WEEP R A NG E control are s h own i n Table 2-2 . Turning
Q

5μ s

at least 25 μ s

t he SW EEP R A NGE control fully C W selects t h e slowest
U Μ

setting of t h e S WEEP R A N G E co n trol . T h us t h e fully C W
Ι

500 ns

at
least
25,4s
Ε

p ositio n h as been d esignated as S WEEP R A NG E position 1
V

50 ns

at least 25 μ s

i n Ta b le 2-2 . R ea d ing h orizo n tally to the r ig h t from t h e
fully C W ( d esignated as position 1 in Table 2-2) S WEEP
R A N G E p osition s h ows, un d er the TIME P OS RN G
column, α value of 50 ms . Contin uing to t he rig h t sh ows
T he maximum
rate
at
w h ic h triggers can be recognize d is

t h at nine ΤΙΜΕ /DI V setti n gs, from 5 ms/ d iv at Χ 1 mag n ifi-
the reci p rocal
of t he minimum trigger h ol d off time s
h own

cation to 10 μ s/div at Χ 500 mag n ification, are availa b le . As
in
Table 2-1 . In R eal-Time operation, d elay
intro d uce d

t he S WEEP R A N G E control is rotate d CC W increasi n gly
using
t
he TIME P OSITIO N controls and t
he d uration of t he

faster Swee p R anges are selecte d .
time win d ow (ten times t he
ΤΙΜΕ /DI V setti n g) must be
a dded to t he minim u m values s h
own in Table 2-1 . T he
Sweep R ange providing t he
greatest time- p ositioning range

It s h oul d be note d t h at t h e n ine ΤΙΜΕ /DI V setti n gs

r
an d t he slowest real-time
sweep can t h erefore cause t he

available at each of t he seven positions of t he S WEEP
2-8
In R andom mo de t
he triggering p oint,
T o ,
is d isplayed
close to t he center line of t h e CR
T with t h e Time P osition
control fully C W an d t h e Time/Div
switc h fully CC W . T he
lowest allowable triggering rate for
t he
7T11
in R andom
mo de is 100 Hz ; th is a pp lies
to
all
eq uivalent-time Swee p
R anges . T he lowest usable
triggering rate for any p articular
Time/Div setting d epe nd s on t
he minim u m d ot den sity t h at
t h e operator is willi ng to use . In R an d om mo d e,
t he
sam p li ng event reference d to α p articular trigger is
timed
from t he p rece d i ng trigger . If t he trigger rate is
h ig h
an
d
uniform, t hen t he sam p ling event pre d iction is more
accurate an d t he sam p les occur w h ere t h ey are p rogrammed
to occur . As t h e rate goes down, t he a b ility to p re d ict w h en
t h e n ext trigger will occur d imi n is h es, and t he sam p les
b egin to h appen in α morerandom fas h io n . Wh en t h e trig-
ger rate slows (or t h e p erio d j itter increases) sufficie n tly,
t
h e pre
d
icta b ility is reduced to t h e p oint w h ere t h e
sam
p li ng d istribution falls over t h e w h ole screen . In t h is
case,
best
d ot d ensity is obtained b y selecting MAN SCA N
and placing t he center of t h e dot d istribution at mi d -scree n .

RΤ
Ε
Ι
Α Μ
L Ε
Ε
Τ
Q Ι
UΜ
Ι
Ε
V
R A NGE control
p
rovi deα total of 63 combinations . Only
27 different TIME/DIV
settings are
available,
h owever,
since most
TIME/DIV
settings are
available at
two or
t
h ree
settings of t he S WEEP R A NG E control . F
or exam p le,
TIME/DIV setti
n gs
of 50 μ
s,
20 μ s
an
d 10 μ s are sh own in
Table 2-2 to be available at all t h ree R eal-Time p ositions of
t
he
S
WEEP R A N
G
E
control
. If
α TIME/DIV setting of 20
μ s/ d
iv
is
re q
uired, any of t
he
t h ree Real-Time Swee p
R anges can be
use
d ; h
owever, more time- p ositioning range
(TIME
P
OS
RN
G) is p rovi de d at t he slower S WE EP
R A N G E settings .
TIME/DIV Settings
Α total of 27 d ifferent swee p rates are available ranging
from 5 ms/ d iv to 10 p s/ d iv in α 5, 2, 1 se q uence (see Table
2-2) . On t he slowest S WEEP R A NG E p osition α total of
nine TIME/DIV settings (5 ms/ d iv to 10 μ s/ d iv) are avail-
able . E
ac
h of t h e six ot h er p ositions of t he S WEEP R AN GE
also offer αch oice of nine TIME/DIV settings .
TA BLE 2-2
O p erating
Instructions-7T11
Swee p R a n ge

TIME P OSRN G

CC W TIME/DIV

30 C W
P osition

and M agnification
Χ 1 Χ
2 .5 Χ 5 Χ 10 Χ 25 Χ 50 Χ 100 Χ 250 Χ
500
Fu lly C W 1

50ms

5 ms

2 ms

1 ms

.5 ms

.2 ms

.1 ms

50 μ s

20 μ s

10 μ s
2

5 ms

.5 m s

.2 ms

.1 ms

50 μ s

20 μ s

10 μ
s

5 μ s

2 μ s

1 μ s
3

.5 ms

50 μ s

20 μ s

10 μ s

5 μ s

2 μ s

1 μ s

.5 μ s

.2 μ s

.1 μ s
4

50 μ s

5μ s

2 μ s

1 μ s

.5 μ s

.2 μ s

.1 μ
s

50 ns

20 ns

10 ns
5

5 μ
s

.5 μ s

.2 μ s

.1 μ s

50 ns

20 ns

10 n s

5 ns

2 ns

1 ns
6

.5 μ s

50 ns

20 η s

10 ns

5 ns

2 ns

1 ns

.5 ns

.2 ns

.1 ns
F ully CC W 7

50 n s

5 ns

2 n s

1 ns

.5 ns

.2 ns

.1 ns

50 p s

20 ps

10 ps
F ig . 2-6 . M ag n ificatio n d e pend s upon t h e p ositio n , wit h i n t he con-
The

nine

TIME/DIV

control

settings d etermine t he

tr
οι wi ndow, of the selected TIME/DIV setting .
amount of d is p lay mag n ification . See F ig . 2-6 . On all Swee p
R
anges the
d isplay
magnification ch anges from Χ 1 to Χ 500
in
α
1,
2 .5, 5 se q
uence as t he selecte d
TIME/DIV
setti ng is

F ig . 2-7 Α an d 2-7 Β s h ow t h at t he d uration of t he d is p lay
changedfrom t
he slowest available rate to t he fastest .

or time win d ow is ten times t h e selecte d TIME/DIV setting .
At t
he S
W
E EP
R A
N
G
E
setting s p ecified in F ig . 2-7 t he
TIME
P
OS
RN
G (ti
m
e p ositioning range) is 50 μ s . Duri ng
SE QU EN TIA L
op
eration an d wit h
t
he
TIME
P
OSITIO N
TIME
P OSITIO N
Control

control fully C W (cloc k wise)
t
he start
of t h e d isplay or time
win d ow occurs j ust after trigger recognition (time
T O ) .
T h e TIME P OSITIO N control p ermits d elaying t he
dis-
play or time win d ow start by an amount up to t he value
in d icate d in t he TIME P OS RN G win d ow . Delay intro duced
During R AN
DO
M
e qu ivalent-time sam p ling α lea d -time
by t h is control is remove d by turni n g t he control fully

of a p proximately 1/2 T PR (time-positioning range) is p ro-
cloc k wise . T he F I NE control serves t h e same p ur p ose but

vide d . Trigger
recognition (T O ) will t h erefore occur
at
h
as only about 1% ο as muc h effect as the TIME P OSITIO N
about
25 μ s with t he S WEEP R ANG E setting re p resente
d in
con trol .

F ig . 2-7 .
During R and om sam p ling t h e 50 μ
s of time-
2-9

O p erating Instructions- 7 Τ 11
50 μ s time
P ositioning
range
1

Ι
1

Ι
T
O
RANDOM

1

Ι
T
oSΕ
Q -4'

0

ι

ι

ι

01

ι

ι

ι

0

ο

ι

ι

0

0

0ι ι ι ί
0 10 20 30 40
50 60 70 80
9 0
100
( Α ) ΤΙΜΕ /DIV set at
5μ s position ( Χ 1
magnification)

time ( μ
s)

-0 -
Dis p lay W indo w TIME

Display W indow TIME
P OSITION fully CW

POSITION f ully CCW
1
Ι

Ι
Ι

Ι
50 μ s time

1

1
P ositioni ng
range

11
Ι
1

Ι
T
O
RANDOM
Ι

Ι
1

Ι
Τρ S EQ -}
Ι
0 10 20 30 40 50 60 70 80 90 100
( Β
)
ΤΙΜΕ /DIV
set at
1 μ
s
position
(
Χ 5 magnification)
F ig . 2-7 .
E ffect of TIME P OSITION control
(SWEEP RANGE at 5μ s/div to 10 ns/ d iv position) .
p ositioning range shown
in Fig . 2-7 Β p ermits seeing from

voltage reference
. ΕΧΤ in p ut allows the

7T11 to be d riven
25 μ s before T o to 35 μ s
after T o .

from
other swee p sources, with t he SCAN control acting as
an
attenuator . Single Swee p op eration h as not been p ro-
vi de d , but is p ossible by ΕΧΤ INPUT d rive from α R eal-
The
TIME P OSITION control
also works d uring R eal-

Time Sweep p lug-in .
Time
o p eration . The smaller the d elay
from T o t he brighter
the dis p
lay .
As
mentione d above, turning the
SCA N control clock-
wise
increases the scan rate .
At faster scan rates the h
ori
SCAN Co n trol

zontal s p
acing between d ots is
increase d . Fewer sam p les p
er
scan
are taken, resulting in
α
d
ecrease in d ot d ensity .
During R eal-Time
operation the SCAN control an d p ush-

Counterclockwise rotation of the
SCAN control h as the
buttons are ino p erative an
d t he p ushbutton lights go out
.

o pp osite
effect ; scan rate d ecreases an
d d ot d ensity is
increase d .
The SCAN
control serves three functions,
selecte d by
the pushbuttons .
P ushing in the REP pushbutton
results in
α free-running
sweep, the scan rate increasing
with C W
rotation of the SCAN
control . Selecting MAN gives α
single
point of time on
the screen, or centers the distribution
of
sam p les aroun d α
point on the screen . This
control also
p rovi d es α means
of setting the SWEEP CAL a d
justment for
10 centimeters
of scan using α built-in zener d io d e as
α
2-10
Display W
i n dow

Display W indow
TIME
P OSITION

TIME
P
OSITION
f ully CW

f ully
CCW
i-_________ ______
__-^
Ι
T RIG LEVEL an d STABILITY Controls
These controls p rovi d e control of the Schmitt trigger
circuit as in α conventional oscillosco pe . R otation clockwise
from α central position picks up triggering on α more and
more positive p ortion of the wave ; counterclockwise fro m
mid range p icks up triggering from more and more negative