Tektronix 576 - Page 27

+ ΝΡΝ H
O R IZ CA
L
- ΡΝΡ
H O R IZ Z ER O
AC VER TZ ER O
AC H O R IZ CA L
AC
N
O RM CA L
1
1
-- λ
1
1
1
ι
-- λ
1
AC VER
T CA L
ι
- _ ΡΝΡ N O RM Z ER O
ι + ΝΡΝ N O RM CA L
ι
Ι
4
+ ΝΡΝVER TCA L
- ΡΝΡ VER T Z ER O
AC H O R IZ Z ER O
F ig . 2-20 . P ositions o f s p ot on C RT gratic ul e w h en ZER O or CA L b u tto n s a re pr essed,
f
or various
p os i tions o f t h e P
O
L AR I TY switc h and
t h e DI S PL AY O FF S ET Selection switc h , assumi ng t h e p osit i on cont r o
l
s are centered .
Wh en the VER TICA L switc h is set to ST
EP
G EN,
ste p s in d icating t he Ste p Generator outp ut are d is p laye d
vertically . T he vertical d is p lay s h ows one ste p p er d ivision
and t he am p litu de of eac h ste p , as s h own by t he PER ST EP
rea d out, d ete r mines the vertical d eflection factor . It s hou l d
be note d t h at if t h e H O R IZO N TA L switc h is set to ST EP
G EN, t he Step Generator outp ut signal is not available for
d is p lay vertically
.
In t h is
case, setting t he VER TICA L
switc h to ST
EP
G EN causes
ze
r o vertical
signal
to
be dis-
p laye d .
T h e vertical sensitivity can be
increase d by 10 times for
any of t h e p reviously mentione d measurements by
setting
t h e DIS PL AY O FF SE T Selector switc h to VER T X10 . The
magnifie d 'vertical d eflection factor can be d etermine d
eit h
er
from t
he PER VER T DI V r ea d out' or by d ivi d ing
t he setting of
t h e VER TICA L switc h by 10 .
H orizontal M easu r ement a n d Deflection
F
actor
In t he h orizontal d imension, t h e d is p lay on
t h e CR T
measures eit h e r collector to emitter
voltage ( V ςΕ ), collec-
tor to base voltage ( V ςΒ ), base to
emitter voltage
(VBE),
emitter to base voltage
(VE B)
or t he Ste
p
Generator out-
p ut . T he H O R IZO N TA L switc h , t he Terminal Selector
switc h an d t he p arameter being
measure
d
vertically d eter-
mine w h at is measure d h orizontally .
'Th e PER VERT DI V reado u t does
not
indicate
def l ection f ac-
tors less t h an 1 ηΑ /division .
Β
Operating
Instructions- Type
576
T he h orizontal
d eflection factor of t h e d is p
lay on
t h e
C R T is controlle
d by t he H OR IZO N TA L switc h and t h e
DIS
PL
AY O
FF S E T Selector switc h . T he PER H O R IZ DI V
rea d out to t he rig h t of t he CR T indicates t h
e
h orizontal
d
eflection factor due to t he combine d effects of t h ese two
controls .
U n d er normal o p erating con d itions with collector cur-
rent being
measured vertically, t he Terminal Selector switc h
set to EM ITT E R G R O UN D
E
D an d t h e DIS PL AY O FF S
E
T
Selector switc h set to N O RM (O FF ), t he d is p lay will meas-
ure
V ςΕ
or
V ΒΕ h orizontally . To measure V ςΕ , t he H O R I-
ZO N TA L switc h must be set wit h in t h
e
CO LLE
CTO
R
range w h ic h h as d e
f
lection facto r s between 50 m
V /division
and 200 V / d ivision . To measu r e V BE, t he H O R IZO N TA L
switc h must be set wit h in B AS
E
range w
h
ic
h h
as
deflection
factors between 50
m
V
/
d ivision
an
d 2 V
/
d
ivision
. In both
cases, t he h orizontal d
eflection
factors
are in d icate d by
both t h
e PER
HO
R IZ DI V rea d o u t and t he p osition of t he
H
O R IZO N
TA L switc h . T he two values s h oul d coincide .
Wh en t h e Terminal
Selector switc h is set to B AS E
G R O UN D
E
D t
he h orizontal d is p lay measures collector to
base voltage ( V ςΒ ) wit
h t
h
e H
O R
IZO N TA L switc h i n t he
CO LLE CTO R range, or emitter to base
voltage ( V ΕΒ ) wit h
t h
e
H O R IZO
N TA L switc h in t he B AS E range . It s h oul d be
note d t h at
V ΕΒ in t h is case d oes not in d icate α measu r e-
ment of t h
e emitter-base voltage und er α reverse biase d con-
d itio
n
. It is
α measurement of t he forwar d biase d base-
emitter voltage
wit h t h e h o r izontal sensing lea d s reverse d .
2- 1 9
0
mmmmmmmm 0
MMMMEMMMM
~
I
_+NPN
I
t T --
. .
I g
MM
M
AMMMMUMM
MMEMEMMMME
.0
MM mom
MM M
OL
+
ΝΡΝ N O RM ZER O
- ΡΝΡ NO RMCA L
I l
:Ll
+ ΝΡΝ H O R IZ Z ER O
- ΡΝΡ H OR IZ CA L
I I
I