Specifications

1.
Multiply 3
divisions
by the
VOLTS/DlV switch
setting
to
determine the
dc-level
value.
2. To the Channel
2
input
apply a
negative dc
level
(or
a
positive
level, using
the Channel
2
INVERT switch)
of the
value determined
(see
Figure
168).
3. Depress the
ADD
push
button to
put
the
resultant
display within
the operating
range
of the
POSITION
controls
(see
Figure 16C).
4. Release the CH
1 and
CH2
push
buttons to
eliminate
possible
confusion,
if
you
wish
to
view
the
ADD
display only.
COMMON-MODE
REJECTION
The
ADD
mode can
also
be used
to display signals that
contain undesirable components. These undesirable com-
ponents
can be
eliminated
through common-mode
rejection.
The
precautions
given
under
the
preceding
Algebraic Addition should be observed.
EXAMPLE:
The
signal applied
to the
Channel
1 input
contains
unwanted
line
frequency
components
(see
Figure
17A). To
remove
the undesired components use the
follow-
ing
procedure:
@
CH
1
SIGNAL
WITH
UNWANTED
LINE
FREOUENCY
Iq'
COMPONENT
9q
CH
2 SIGNAL
FROM LINE
FREOUENCY
SOURCE
(INVERTED)
SIGNAL
WITH
LINE FREOUENCY
COMPONENT
CANCELED
OUT
IB)
RESULTANT
SIGNAL.
I
738-19
(A}
CH
I AND
CH
2 SIGNALS,
4658/DM44
Operators
Figure 17. Common-mode
rejection.
45