Tektronix 454A - Page 159

F i g . 5- 14 . ( zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ‘
)
Locat i o n of ‘ Tr i gger L evel Cent er ad j u st ment ( ‘
Sweep ci r c u i t b oar d ) . ( ’ ) L ocat i on of ’
Tr i gger
L evel Ce n t er
A dj ust me
n
t ( ’ Sweep ci r c
u
i t boar d ) .
j . AD JU ST- ’ Tr i gger L evel Cent er i ng ad j u
st ment
R 843
( see
F
i g .
5- 14) f or
± st a
b
l e
d i s p
l ay .
25 . A d j ust Tr i gger P r eam p DC
L
evel and
N or mal
Tr i gger DC L evel
± . Set t h e V er t i cal M OD E swi t c h t o C H 1, t h e T R I GG ER
swi t c h t o C H 1 O NL Y, an d t h e ‘ T R I GG ER I N G
CO UPL I N G swi t c h t o DC .
b . M ove t h e t r ace t o t h e
cent er h or i zont al l i ne wi t h t he
C H 1 P OSI TI O N cont r ol .

T r i gger DC
L
evel
a d j u st ment s .
( ’
)
h . B e s u r e t h e ’ LEVEL cont r ol i s set t o 0 .
i . C HE C K - St a b l e C R T d i s p l ay .
A d j ust ment - 454 ‘ / R 454
‘
c . C HE C K - St a
b
l e
C R
T
d i s p l ay . C H 1 l i g h t i n b ot h ‘
an
d
’ Tr i gger i ng must
b e
on .
d . AD JU ST- Tr i gger P r eam p DC L evel a d j u st ment , R 511
( see
F
i g .
5- 15)
f or ± st abl e d i s p l ay .
e . Set t h e T R I GG ER swi t c h t o N O RM .
f . C HE C K - St a b l e C R T d i s p l ay .
g . AD
JU
ST- N or mal Tr i gger
DC L evel a
d j
ust ment , R 272
( see F i g . 5- 15) f or ± st a b l e di s p l ay .
F i g .
5- 15
.
( ‘ ) L ocat i o n of Tr i gger P r ea mp DC L evel a n d
(
’ ) N or mal