Tektronix 2213A Operator's Manual

Ph ase Diffe
r
e n ce
In α simila
r
man n er to
"Time Difference B etween Two
Time- R elate d
P
ulses" ph ase
comparison b etween two sig-
nals of t h e same fre q uency can b e ma
d
e
u sing t he dual-
t r ace feat ur e of t he 2213 Α .
T h
is
met h
od
of ph ase d iffe r en ce
measurement can be used up to
t h
e freq
uency limit of t he
vertical d eflectio n system . To
ma k
e
α p hase com p a r ison,
use
t h
e
followi ng p r oce d
ure
:
1 .
P
reset
i n
strume
n
t
controls and obtain α b aseli n e
trace, t h en set t he ΙΝΤ switc h to
C H 1 .
2 . Set bot
h I np
ut Co
up li n g switc h es to t he same posi-
tio n , depen d i n g on t h e ty pe of
i n
put
cou
p
ling d esi r ed .
3 . U si
ng eit h
er
prob
es
or cab les wit h e q ual time delays,
connect α k nown refe r ence signal to t he C hann el 1 inp u t
an
d
t he unk now n signal to t h e C hann el 2 in p ut .
4 .
Select BOTH
VER TICA L M OD E ; t hen select eit h er
A L T
or
C H
O
P , depe nd i ng on t he f r e q uency of in p ut signals .
T he refe r ence sig n al s hou ld p r ecede t he compariso n sig n al
in time .
5 . If t he two sig n
als
are of
op posite p olarity, p ress
i n
t h
e
C h
an
n
el
2 I NVER T b
utton to
i n vert
t
h
e C
h
ann el 2
dis p lay .
6 . Set b ot h V O L TS/DI V switc h
es an
d b
ot
h V a r
ia
b
le
cont r ols so t h e displays a r ee qu al in amplit u
de
.
7 . A dj ust t he TR IGG ER LEVEL con trol for α stable
dis p lay .
8 .
Set
t
h
eS
E
C/DI
V
switc
h
to α swee p speed w h ic h
dis p lays ab
o
u t
o
n
e
f u ll
cycle on t h e waveforms .
9 . P ositio n t he d is p lays and a dj ust t he S E C/DI VV ari-
able con t
r
ol so t
h
at o n e r efere n ce-sig n al cycle occ up ies ex-
actly
8
h
o
r
izontal gratic u le divisions at t he 50% r ise-time
points (see
F ig
u re 4-8) . Each division of t he g r aticule now
r ep r ese n ts 45° of t he cycle (360°
-
8 d ivisio n s), an d J
h e
h orizontal
graticule cali b ration can be state d as 45° /p er
d ivision
.
10 .
M easure t h
e
h
o
r izontal differe n
ce
between
co
r-
responding p oi n ts on t he wavefo r ms at α common h o r izo n -
tal graticule line (50% of r ise time) and calculate t he ph ase
difference u sing t h e following formula :
h orizo n tal
Ph ase h orizo n tal graticule
Difference = diffe r ence χ
(divisio n s) cali b ration
(deg/ d iv)
E xam p le : T h e h orizontal differe n ce is 0 .6 d ivision wit h α
graticule calibratio n of 45° p er divisio n as sh own in F ig-
ure 4-8 .
S u bstituting t he given val ues into t hep h ase d iffere nce
fo r m u la :
Ph ase
differe n
ce
=
0 .6
div χ
45°/
d iv = 27° .
M ore accurate ph asemeasurements can be ma de b y us-
i ng t he Χ 10 M agnifier functio n to i n crease t h e sweep sp eed
wit hout ch an ging t he SE C/DI V V ariable control setting .
E XA MPLE : If t he swee p spee d were increased 10 times
wit h t h e magnifie r ( Χ 10 M agn ifie r b utto n out), t he mag n i-
fied h orizo n tal graticule cali b ratio n woul dbe 45°/division
d ivi d ed by 10 (or 4 .5°/divisio n ) . F ig u re 4-9 sh ows t he
same sig n als ill u strate d in F ig ur e 4-8, but mag n ifyi ng t he
dis p lays res u
lts in α h orizontal
difference of 6 d
ivisio n
s
between t h e two signals .
Substit u
ting t h
e
given values i n t h
e p
h ase differe n ce
fo
r
mula :
Ph
ase
difference = 6 div χ 4 .5°/ d iv = 27° .

Tektronix 2213A Specifications

General

Brand	Tektronix
Model	2213A
Category	Test Equipment
Language	English