Tektronix 2213 Service Manual

Operati ng Instructions-2213
Service
O PER
ATI N
G CO
N SID ER ATIO N S
T h e following basic
operati ng informatio n and tec
h -
n i qu es s h oul d b e
consi
d
ere d before attem p ting any
meas u rements .
G R ATIC ULE
T h e gratic
u le is internally ma rk e d on t h e facep late of
t he crt to enable
accu rate meas u reme n ts wit h out p arallax
error (see
F
igure 2-8) . It is
mar k e d wit h eig h t vertical and
te
n h orizontal ma j or d ivisio n s . Each ma j or divisio n is
d ivi d e d into five su b d ivisions . T
h
e vertical d
eflection
factors and h orizontal timing are cali b rated to
t he graticule
so t hat accu rate measurements can
be ma d e d irectly f r om
t he crt
.
Also,
perce ntage mar k ers for t h e meas u rement
of
rise
an
d fall times are locate d on t he left side of t h e
graticule .
2-
8
G
R
O
UN DI N G
T h e most reliable
signal measurements are ma d e w h en
t
he
2213
an d t he unit un d er test a r e con necte d by α com-
mo n reference (groun d lead), in a dd ition to t he signal lea d
or
p ro b e . T h e probe's grou nd lea d p rovi d es t he b est
g
r
oun
d
ing met h od for signal interconnection an d e nsu r es
t he maxim
u m amount of signal-lea d sh iel d ing in t he prob e
ca b le . Α se p arate
groun d lead can also b e connected from
t he unit
un
d
er test to t h e oscillosco p e G N D con n ector
locate d on t
h e front p anel .
1ST O R LEF T

C
EN T ER

11TH
O R R IGH T
VER TICA L
VER TICA L VER TICA L
G R ATIC ULE
GR ATIC ULE GR ATIC ULE
L I NE

L I NE

L I NE
R IS E AND

C
ENTER
F ALLTIME

H O R IZO
N
TA L
M E
AS
UREMEN T

G R ATIC ULE
PERC
EN TAG E

L I NE
M A RKER S
4115-16
F ig ur e 2-8 . Gratic u le meas
u re m e n t m ar k i n gs .
SIG
N A L CO NNE CTIO N S
Generally, probes offer t h e most convenie n t means of
connecti ng
an
inpu t signal to t h e instrument . T h ey are
s
h
iel d
e
d to
prevent p ic ku p of electromagnetic interference,
a
n
d
the sup p lie d 10 Χ prob e offers α h ig h in put im p edance
t hat minimizes circ u it loading . T h is allows t h e ci r cuit u
n
d er
test to o p erate wit
h
α mi
n
imum
of
c
h ange from its n ormal
con d itio n as measurements
are
b
eing ma
de
.
Coaxial cab les may also be u se d to connect signals to t he
in p u t connectors, but t h ey may
have
consid
erable effect
on
t he accuracy of α d
isplaye
d
waveform .
To
maintain t he
original frequency c
h aracteristics of
an
applied signal,
only h ig h - q uality, low-loss coaxial cables s h ould be u se d .
Coaxial cab les s h oul d be terminate d at bot
h en
d s
in t h eir
ch aracteristic im p ed a nce . If t
h
is is
not
p ossi
b le, use suitable
im p eda n ce-matc h ing d evices .
I NPU
T
CO
UPL I N
G
CA P ACITO
R PRE
C
H A R GI N G
Wh en t he in put cou p li ng switc h is set to GN D, t he i n put
signal is connected to groun
d t h rough t h e in p ut coupling
capacitor in
series wit h α 1- ΜΩ resistor to form α p re-
ch arging
networ k .
T
h
is
networ k allows t h e in p ut coup ling
cap acitor
to c h arge to t he average d c-voltage level of t he
signal ap p lie d to t h e probe . T h us, any large voltage
tra n sients t h at may acci d en tally be ge nerated will not be
applie d to t h e am p lifier in pu t w h en t he inp u t cou p ling
switch is move d from GND to AC . T h
e p rec
h arging
n
et-
wor k also p rovi d es α meas u re of p rotection to t
h
e external
circuitry by re d ucing t he cu rrent levels t
h
at can be d rawn
from t he extern al circ u itry during capacitor c
h arging .
T h e following p roce dure s hould be used w h enever t he
probe tip is connecte d to α signal source h avi ng α d iffe r ent
d
o level
t
h
an
t h
at
previously app lied, es p ecially if t he d c-
level differe nce is
more t h
an
10 times t he V O L TS/DI V
switc h setting :
1 . Set t h e AC-G N D-DC switch to G ND before con-
necting t h e p robe ti
p
to α
signal source .
2 . Insert t h
e pro
b
e ti p into t he oscillosco pe GND
connector
.

Tektronix 2213 Specifications

General

Brand	Tektronix
Model	2213
Category	Test Equipment
Language	English