Tektronix 454A User Manual

O p er at i ng I nst r uct i o n
s- 454zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ‘ / R 454A
Common- M o de R e j ect i on

5, Set t h e TRI GG ER
swi t c h t o N O R M ,
T h e ADD f eat ur e of t h e 454 ‘ can be used t o di sp l ay
si gnal s w h i c h cont ai n un d esi r a b l e com p onent s . T h ese
un d esi r a b l e comp
one
n t s
can
be
el i mi nat ed
t
h r oug h
common- mo d e r e j ect i o n . T h e pr ecaut i ons gi ven un d er
Al ge b r ai c Addi t i on s h oul d b e o b ser ved .
1 . Co n nect t h e si gnal co n t ai n i ng bot h t h e d esi r e d and
un d esi r e d i nf or mat i on t o t h e I NPU T C H 1 co nn ect or .
2 . Con n ect ± si gnal si mi l ar t o t h e u n wa n t ed p or t i on of
t h e C h a n nel 1 si gnal t o t h e I NPU T C H 2 co nn ect or .
6 . Set
t h e M
OD
E swi t c h t o ADD . Pul l t h e I NVER T
swi t c h so t h e commo n - mode si gnal s ar e of o pp osi t e
pol ar i t y .
7 . Ad j
ust t he C H 2 V O L TS/ DI V swi t c h a n d C H 2
V A R I A BLE co n t r ol f or maxi mum ca n
cel l at i on of t h e
commo n - mo d e si gnal .
8 . T h e si g n al w h i c h
r emai n s s h oul d b e onl y t h e d esi r e d
po r t i on of t h e C
h annel 1 si gnal . T h e un d esi r e d si gnal i s
cancel l e d out
.
Exam p l e . An exam p l e of t h i s mo d e of o p er at i o n i s
3 . Set b ot h I nput Co up l i n g swi t c h es t o DC ( AC i f DC

s hown i n F i g . 2- 30 . T h e si gnal a p p l i ed t o C h an n el 1
com
p
onent of i n put si gnal i s t oo l ar ge) .

co n t ai ns unwant ed l i ne- f r eque n cy component s ( see
F i g .
2- 30 ‘ ) . ‘ cor r es p o n di ng l i ne- f re q u ency si gnal i s con n ect ed
t o C h annel 2 ( see F i g . 2- 30 ’ ) . F i g . 2- 30C s h ows t h e
desi r e d
4 . Set t h e M
OD
E swi t c h t o A L T . Set t h e V O L TS/ DI V  por t i on of t h e si g n al as d i spl ayed
w h
en
common- mo d e
swi t c h es so t h e si gnal s ar e a b out equal i n am p l i t ud e .

re j ect i o n  i s
use
d .
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1 13 , 00MEMEME " " " " œœ " " " "
" " " "
œ• " " " " " " " " œœ " " " "
( ‘ ) C
h
an n el
1 si g n al .

(
’ ) Ch a nn el 2 si g
n
al
.

( C) R esul t a
n t di s p l ay .
F i g . 2- 30 . U si n g t h e ADD f eat ur e f o r commo n - mo d e r e j ect i o n . ( ‘ ) C h a nn el 1 si g
n
al co
n t ai n s d esi r ed i n f or mat i o n al o n g wi t h
l i n e- f r e qu e n cy
co mp one n t .
(
’
)
C h an n el 2 si g n al con t ai n s l i ne- f r eq u e n cy onl y, ( C) C R T d
i s p l ay u si ng com m o n - mo d e r e j ect i o n .

Tektronix 454A Specifications

General

Brand	Tektronix
Model	454A
Category	Test Equipment
Language	English