Tektronix 7B71 User manual

-

_

_ _~
: r

-

z s

r

-
ί .. ι .

1

+

_

7

~

.

. _

.
.

..

.

-

~

.

ι !" :_

`1

~

`=
ςΓ -
Ν

1

λ

_

. .~ ν
^>
ν

λ =,
.
εχ
,-
t,

-

F Y ,~~~ -,

α -i

J+ .ι
=" .'
νε ~ ς .

.~,_

_

.
. ,~ ~ _, . . : .

.~
.~~i~~--~~+}-
ξ
, : . ι

~ ._ ;~ .11~-i ι
~xr
. .
.
.~

.r,
._ .~ τ _ .

.

.,

~
. _- τ ^

.>

.
., .
.

~

, ._

'1 1 F7" ,

wc af
ι
i
;
o i n 7z'i - f-~

,
aronix monsfarners
pinto, am . i
ul fKa inshuxmi
Puy
:
AiwA6 i -
ιe
dlki'od
" ~ d
to the
in your
procedure will
ass u re
you the
f,osie 5 i possible service
.
IfIcase include the
niOrun - iz-ni "Iype and Soricii or Model
Nuin-
ber with A recluesis
io,- ports or service .
)eC ;I' ;ca6ons
(1n(2
price chonge privi-
rEmyeed .
i' = , , 'klrionix, Inc . .
ted
in
the Wited'
COOMMS OY A
$ publvatim may no , he
Oducad
in un, Ono
without
'Wands6un
COV .yrig
Π
i ownei,

SE CTIO
N
1
SECTION 2
P age
S PECIF ICATIO N S
Introduction
1-1
E lectrical C h aracteristics 1-1
Swee pR ate 1-1
Swee p Acc u racy 1-1
Swee p L engt h 1-1
Swee pH ol d -Off Time 1-1
V ariable - Time Delay 1-1
Delay Time Accuracy 1-1
M ulti p lier Incremental L inearity 1-1
J itter 1-1
Differential Ti m e M easure m ent Accuracy 1-2
Trigger Sensitivity 1-2
Internal Trigger J itter 1-2
External T rigger In p ut 1-2
L evel R ange 1-2
Ρ - Ρ Auto Sensitivity 1-2
E
nviron m e n tal C h aracteristics
Altitude 1-2
Ph ysical C h aracteristics
F inis h
1-2
Dime n sions 1-2
W eig h t 1-2
O P ERATI N G I N STR U CTIO N S
General 2-1
Installation
2-1
F ront P
anel
Controls
2-1
Test Setu p C h art
2-4
General O p erating Infor m ation
2-4
Swee p Calibration C h ec k 2-4
Si m plified O p erating Instructions 2-6
Normal Swee p 2-6
M agnifie d Swee p 2-6
Delaye d Swee p 2-6
P us h button Switc h L ogic 2-6
Triggere d L ig h t 2-7
Trigger M o d e 2-7
Trigger Cou p ling 2-9
Trigger Source 2-10
Trigger Slo p e 2-10
Trigger L evel 2-10
H ori z ontal Swee p R ate 2-12
Swee p M agnifier 2-12
H ori z ontal P osition Control 2-13

Page
SECTION 2 OPERATING INSTRUCTIONS (cont)
Applications
2-13
General
2-13
Measurement Techniques
2-13
Time Duration Measurements
2-14
Determining Frequency
2-15
Risetime Measurements
2-15
Delay Sweep Time Measurements
2-16
Delayed Sweep Magnification
2-17
Displaying Complex Signals Using Delayed Sweep
2-18
Pulse Jitter Measurements
2-18
SECTION 3CIRCUIT'
DESCRIPTION
Introduction
3-1
Block Diagram Description
3-1
Detailed Circuit Description
3-1
Trigger Input
3-1
Input Source 3-1
Trigger Amplifier
3-2
General
3-2
External Input
Amplifier 3-2
Input Stage
3-2
Peak Detector
3-3
Slope Comparator
3-3
Output Stage
3-4
Trigger
Generator 3-4
Trigger Pulse Generator 3-4
Sweep
Gate Stage 3-4
Triggered
Hold-Off Stage 3-4
Bright Line Auto 3-5
Time-Base Generator 3-5
General 3-5
Normal Trigger Mode Operation 3-5
Single Sweep Operation 3-8
Alternate Operation 3-8
Delayed Sweep Operation 3-8
Delay Pickoff 3-9
Horizontal Preamp 3-9
Readout Block 3-9
SECTION 4 MAINTENANCE
Preventive Maintenance
4-1
General
4-1
Cleaning
4-1
Visual Inspection 4-1
Transistor and Integrated Circuit Checks
4-1
Recalibration
4-1

CHANGE
INFORMATION
Abbreviations and symbols used in this manual are based
on
or
taken directly from IEEE Standard 260 "Standard Symbols for
Units", MIL STD-12B and other standards of the electronics
industry . Change information, if any, is located at the rear of this
manual .
SECTION 4 MAINTENANCE (cont) Page
Troubleshooting
4-2
Troubleshooting Aids
4-2
Troubleshooting
Equipment 4-2
Troubleshooting Techniques 4-2
Corrective Maintenance 4-6
General 4-6
Obtaining Replacement Parts 4-6
Soldering Techniques
4-7
Component
Replacement 4-7
Instrument
Repackaging 4-10
SECTION 5 PERFORMANCE
CHECK/CALIBRATION
Introduction
5-1
Test Equipment Required 5-1
Short-Form Procedure and Index
5-2
Performance Check/Calibration Procedure
5-4
General
5-4
Preliminary Control Settings 5-5
Check/Adjust Steps (refer to Short-Form Procedure 5-6
for index to steps)
SECTION 6 ELECTRICAL PARTS LIST
Abbreviations and Symbols
Parts Ordering Information
Index of Electrical
Parts
List
SECTION 7
DIAGRAMS AND MECHANICAL PARTS ILLUSTRATIONS
Diagrams
Mechanical Parts Illustrations
SECTION 8 MECHANICAL
PARTS LIST
Mechanical Parts List
Information
Index of Mechanical
Parts Illustrations
Mechanical Parts List
Accessories

7 Β 71
F ig . 1-1 . 7Β 71 Delaying Time Base .

In tro d uction
VA R IA BLE R ange
( u ncali b
rate
d )
5 s/ d iv to 0 .1
s /div an d 0 .2
μ s /d iv
to 0 .02
μ s /d iv
50 ms/ d iv to
0 .5 μ s/ d iv
Over any 2 div
i n terval wit h in
center 8 d iv
Ch ange information, if any, affecting t h is section will be found at t h e rear of t h e man u al .
T he 71371 Time Base U nit is d
esigne d specifically for use
with Te k tronix 7700-Series
Oscillosco p es . H owever, it is
com p ati b le wit h all 7000-Series Oscillosco p
es . T he 71371
p rovi d es cali b rate d swee p s from 5 seco
n d s/ d ivision to 0 .02
microseco n ds/ d ivision (2
nanosecon d s/ d ivision with Χ 10
M AG N I F
I ER ) . Sweep r ates may b e varie d continuously
( u ncali b rated) between calibrate d steps . Swee p triggeri ng is
to 200 mega h ert z or ve r tical a m p lifier b an dwid th, w h ic h -
ever
is less
.
T h e d elaying sweep feature of the 71371, in
delaye
d swee p operation, gives co n tin u ous sweep d elay
from 0 to 10 times the setting of the ΤΙΜΕ /DI V O R D L
Y
5 secon d s/ d ivision to 0 .02 micro-
seco n d s/ d ivisio n in α 1-2-5 se-
qu ence . Χ 10 mag n ifier exten d s
swee p r ate to 2 n an oseco nd s/
d ivision .
Continuously varia b le betwee n cali-
br ate
d sweep
rates
.
Extend s uncali-
b rate d sweep
rate to at least 12 .5
seco nd s/ d ivision .
M easure d in 7700 series mainframe
+15 0 C to +35 ° C

0 0 C to +50 ° C
U η m αg Κ I _-_
Μ α
9
_ Γ ._
U nmag T M
ag
_ ._ .
3% ο
TA BLE 1-1
Electrical C ha r acteristics
TIME selector . T h e sweep free-runs provi d ing αb rig h t b ase-
line in t h e a b se n ce of ade qu ate triggeri ng signal i nΡ - Ρ
A U TO a nd AUTO t r iggering mo d es .
T h e P erformance C h ec k proce du re
given in Section 5 of
t h is man u al p rovi d es α convenient met h
od of ch ec k ing p er-
formance of t h is instrument .
T h
e
followi ng elect r ical
ch aracteristics apply at
an ambient tem p erature of 0 0 C to
+50 0 C, unless ot h erwise
noted . W armu p time for given
accuracy is 20 m inutes .
Exclude Following
P ortions of
Sweep H ol d-Of f Ti m e
5 s/ d iv to
5 μ s/ d iv
2 μ s / d iv to
0 .02 μ s/ d iv
Varia b le Time
Delay
Delay
Time
Accuracy
5 s/ d iv to
1
s/div

W ithin 2% ο
Multi p lier
Incremental
L inearity

W it h in 0 .2%
10 d ivisions to 13
divisions . s .
713711
En d of Swee p ; b eyon d 100 divisions
J itter

1
1 part o r less in 50,000 of 10 ti m es
t he ΤΙΜΕ /DI V setting

Sp ecification
--7 Β 71
Trigger Sensitivity
T
ABLE 1-1 (cont)
-------------
Perfor m ance Characteristic
Differential Time
Measurement
Accuracy
Delay Time
1 μ sto0 .5s
1 sto5s
ουριιη g
AC
AC LF REJ Z
AC HF REJ
DC
Single Sweep
Internal Trigger Jitter
W ithin 1°/ ο and 2 minor divisions
W ithin 2°/ ο and 2 minor divisions
Triggering
Fre q uency
sweep only .
Minimum Trig-
gering Signal
R equire d
__
I
_
NT_
.___
ΓΕΧΤ
___
7575 mV
375 mV
75 mV
375 mV
75 mV
75 mV
375 mV
Triggering re quirements same as
nor m al swee p . When triggere d ,
swee p generator p rod uces one
1 n anosecond or less at 150 mega-
hertz .
TABLE 1-1 (cont)
_ ._ . . :
Characteristic

Performance
Input
R and C
L evel R ange
(Excluding
Ρ - Ρ AU TO)
ΕΧΤ
ΕΧΤ = 10
Ρ - Ρ AUTO op eration
Sensitivity
L ow Freq
uency
R es p onse
Characteristic
Altitude
1 megohm
within 2%, 20 picofarads
within
2 p icofara d s .
At
least +1 .5 volts to --1 .5 volts .
At
least +15 volts to --15 volts .
0 .5 div
Internal, 125 millivolts
E xternal
200 Hz to 20 MHz . U pp er
frequency
an d am p litude limits
same
as NOR M AL Trigger
Sensi-
tivity .
M ust Trigger on50
h ertz, 2 division
signal .
TABLE 1-2
E nvironmental Characteristics
This instrument will meet the electrical characteristics given
in Table 1-1 over the following environmental limits .
E xternal Trigger Input
M aximu
m
I nput 500 volts (DC + P eak AC) . 500
Voltage volts (P- Ρ AC) at 1 kilohertz or less .
TABLE 1-3
Physical Characteristics
1
On Internal
Triggering
Only ; t he specifie du pp er -3 dB frequency
Finish Front panel is anodize d aluminum
.
of the V ertical System replaces upper limit fre
q uencies in t he
above
table
when the number in the table is
greater than the -3dB Dimensions
Fits single plug-in com partment of
frequency of the Vertical System .
7000-series
oscilloscope
.
2 W ill not trigger on sine waves of 3 divisions or less internal or 1 .5
volts external below 120 Hz .
W eight A p
proximately 2 .88 poun d s .

General
Installation
General
C hange information, if any, affecting this section will be found at the rear of the manual .
The 71371 d elaying sweep p lug-in unit op erates with α
Tek tronix 7000-series in d icator oscillosco p e and α 7A-series
vertical plug-in un it to form α complete oscillosco pe
system . To use t he 71371 effectively, its o p eratio nand
capabilities sh oul d be kn own . 'T h is section d escribes t he
ope r ation of t he front- p anel controls, gives first-time and
general o p erati n g information and lists some basic a pp lica-
tions for th is i n strument .
The 71371 is desig ned to op erate in t he h orizontal p lug-in
com p artments of Tektronix 7000-series oscilloscopes . The
71371 can also b e installe d in α vertical p lug-in com p artment
to p rovi d e αsweep t h at ru n s vertically on t he CRT . How-
ever,
w hen
use
d in
t
h is
ma nn er, t h ere is no retrace blan k ing
or i n ter n al
triggering
p rovision
an
d
t
he
unit may not meet
t he s p ecifications given in Section 1 .
The instructions in
this manual are writte n for use of t he 71371 in α h orizontal
p lug-i n com p artment of t h e oscillosco p e .
Wh en t he 71371 is u se dwith an oscillosco pe w h ic h h as
two h
orizo n tal p lug-i n com p artments, install t h is unit i n t h e
Α (DE L AYI N
G TIME BASE) compartment . Then, if a
d elaye d -swee
p
unit is installe d in t he Β (rig h t) compart-
me n t, d elayed-swee p o p eration is available . 'T he 71371 will
operate p ro p erly in t he Β com partment for
all
h
orizo n tal
mo d es of operation excep t d elayi ng swee p .
To
install the 71371 into
α p lug-in co m partment, push it
in u
n
til it fits firmly i
n to
t he indicator p lug-in com p art-
ment . To remove, pull t he release latc h (see Fig . 2-1) to
dise n gage t
he
unit
from
t
he
i n d icator and pull it out of t he
p lug-in compartment . Even t h oug h t h e h orizontal gai n of
t he in d icator oscillosco p e is sta nd ar d ize d to min imi ze
a d j ustme n t w h en i n serting p lug-in units, t he sweep calib r a-
tion of t he 71371 sh oul dbe c h ec k ed w hen it is inserte d into
t h e in d icator to verify measureme n t accuracy . The pro-
ce d ure for check ing the unit is given und er Swee p Cali b ra-
tion C h eck in t h is section .
FRONT-PANEL CONTROLS
All
controls requi r e d for t he o pe r ation of the
71371
are
locate d
on
t he front p anel of
t
he u n it (see Fig . 2-2) . To
Α
F ig . 2-1 . Locatio n of release
latc h .
ma ke full use of t he ca p abilities of t h is i n stru m e n t, t he
o pe r ator s h oul d be familiar wit h t he fu n ctio n an d use of
each of t h ese con trols . Α b r ief descri p tion of t h e fro n t-
p anel con trols an d con n ector is give n h ere . More d etailed
informatio n
is given under Ge n eral O p erating Information .
Triggering Controls
713711
LEVEL IS L O PE

Selects t he amplitu de p oi n t a nd
slope of trigge r signal on w h ic h t he
sweep is triggere d . Wh en t he in d ica
tor line on t he outer ring is to t he
left
of center, t he sweep is triggere d
on t he positive-going slo pe of t he
trigger signal, as s h own by t he
p ositive-going waveform . To t he
rig ht of center, t he swee p is trig-
gere d on t he negative-goi ng slo pe of
t he trigger signal as s h own b y t he
n egative-going waveform .
ΤR IG'D

L ig h t in d icates t h at t he sweep is
triggere d and will produce α display
with co r rect setting of t he POSI
TION con trol and t he controls on
t he associated ve r tical unit an d i nd i-
cator oscillosco p e .

Ope r ati ng Instructions-713711
TR IGG ER I NG
TR IG'D "

MODE

CO UPL I NG
LEVEL /S L OPE
Ρ - Ρ
AUTO AC
ι r ιτ
ιη ~ ; ιπι ., , CA L
IN
Ι , ΧΙΜΕ
/DI
V O R D L Y TIME
εΙ

ms
'5 .2 7_ ~lj
2
T RIGG
ER
CO N T RO LS
S WEEP
CO N T
RO LS
T RIGG ER
CO N T RO L
M OD E
2-2
Se r ies
of push-button switc h
es to
select t he trigge r m ode .
Selecte d
mo d e is i nd icated by
lig h te d
b
utto n .
Ρ - Ρ AU TO :
Swee p automatically
t r igge r ed
at p oint selecte d b y t he
LEVEL/SLOPE
control w hen
the tr igge r signal re p etitio n r
ate
is
a b ove a b out 200 h e r tz a nd
wit
h
i n t he freq uency ra n ge
Fig .
2-2 .
Fr o n t- P an el co n trols and
co nn ectors .
selecte d by t h e CO UPL I NG
switc
h . T r igge r ed sweep can b e
o b tai ned
t hroug h out t he r an ge
of t h e LEVEL /S L O PE control .
Wh en t h e t r igge r r ep etition r ate
is b
elow t he lowe r freq u e ncy
li m it
(o
r
above upp e r limit fo r
AC HF
REJ) o r w hen t he tr igger
sig n
al is i nade q uate, the swee p
f r
ee r uns at the swee p r ate
selecte d b y t he ΤΙΜΕ /DI V
switc h to pr oduce α r efere nce
tr ace .