Tektronix 454A - Page 152

Ad j
ust ment - 454zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ‘ / R 454 ‘
F i g . 5- 8
. L ocat i on of V er t i cal O u t pu t A m p l i f i er
Ce n t er i n g an d
Gai n
ad j u st me n t s and R 382 .
15 . A d j ust C h annel
1 and 2 P osi t i on Cent er i ng
b . Set t h e C H 1 P OSI TI O N cont r ol
f or ± met er r ea d i ng
of - 5 . 7 vol t s . ( T h e dot on t h e C H 1 P OSI TI O N
cont r ol
s h oul d be cent er ed mech ani cal l y . I f not , l oose n
t
h
e set
scr ew an d r e p osi t i on t h e k nob) .
e . AD JU ST- C H 1 P osi t i on Cent er a d j u st ment , R 40 ( see
F i g . 5- 7) , t o p osi t i on t h e t r ace t o t h e cent er h or i zont al l i ne .
5- 38
c . Set t h e M OD E swi t c h t o CH 1 .
d .
C
HE C
K - Tr ace at t h e cent er h or i zont al l i ne .
i . C HE C K - Tr ace at t h e cent er h or i zont al l i ne .
j . AD JU
ST- C H 2 P osi t i on
Cent er a d j
ust ment , R 140
( see F i g . 5- 7) ,
t o p osi t i on t h e t r ace t o t h
e cent er h or i zont al
l i ne .
k . Di sconnect al l
t est eq ui p ment .
16 . A d j ust V er t i cal Out p ut
Am p l i f i er T h er mal
Com p ensat i on
± . Set t h e V
er t i cal M OD E swi t c h t o A L T .
b .
P osi t i on t h e ‘ t r ace 3 d i vi si ons above
an
d
t h e ’ t r ace
3 d i vi si ons b el ow
gr at i c u l e cent er .
c . Set t h e ¤™œ• / DI V swi t c h t o 2
ms
.
d . C HE C K- B ot h
t r aces ar e f l at i n t h e ar ea of about t h e
f i r st t wo d i vi si ons .
± . Connect t h e p r eci si on DC vol t met er
bet ween p i n 1 of
P l u g ¡ 35 on t h e V er t i cal P r eamp ci r c u i t b oar d
( see F i g . 5- 7)
an
d
gr o u n d .

e .
AD JU ST- 11382 ( see F i g . 5- 8) f or b est f l at ness of
b ot h t r aces .
T
h
i s i s ± p r el i mi nar y ad j ust ment , an d may h ave
t o be r e- a dj u st e d d ur i ng H i g h F
r e q
u
ency Com p ensat i on .
17 . A
d j ust C h annel 1 an d 2 V er t i cal P r eam p
and
V er t i cal Out p ut
Am p Gai n
± . Set bot h V O L TS/ DI V swi t c h es t o
20 m
V
/ DI
V .
b . Set t h e V er t i cal
M OD E swi t c h t o C H 1 .
c . Connect t h e st an d ar d am p l i t u de cal i b
r at or
( 067- 0502- 01)
o u t put connect or t o t h e C H 1 an d C H 2
I n p u t connect or s
t h r oug h ± 42- i nc h BN C cabl e an d t h e
d ual - i n pu t co u p l er .
f . Set t h e M OD E swi t c h t o C H 2 .

d . Set t h
e st andar d am p l i t u d e cal i br at or f or ± 0 . 1- vol t
out put .
g . Connect t h e p r eci si on DC vol t met er bet ween p i n 1 of
p l ug
¡
135 on t h e
V
er t i cal P r eam p ci r cui t b oar d and gr o u nd

e . Connect t h e 10 § pr o b e t o t h e i n p u t of t h e t est
( see F i g . 5- 7) .
osci l l osco p e .
h . Set t h e C H 2 P OSI TI O N cont r ol f or ± met er r ea d i ng

f . Set t h e t est osci l l osco p e f or ± ver t i cal d ef l ect i on
of - 5 . 7 vol t s . ( T h e dot on t h e C H 2 P OSI TI O N cont r ol

f act or of 50 mi l l i vol t s/ d i vi si on, AC cou p l e d , at ± swee p r at e
s h oul d b e cent er e d mec h ani cal l y . I f not , l oosen t h e set

of
0 . 5 mi l l i secon d / d i vi si on .
scr ew and r e p osi t i on t h e kn ob . )
g . Connect t h e 10 § p r obe t i p t o t h e gai n t est p oi nt ( see
F i g . 5- 7) .