Tektronix 2247A

Basic Applications
Set
the
VOLTS/DIV
control
so
that
the
displayed
signal
will
have
a
good
viewing
amplitude.
For
the
assumed
signal
shown
in
Figure
5-8,
a
setting
of
1
V/div
will
produce
a
four
to
five
division
display
amplitude.
Position
the
ground
cursor
(using
the
VERTICAL
POSITION
control)
at
about
three
graticule
divisions
below
the
center
graticule
line.
(For
negative-going
signals,
two
divisions
above
the
center
graticule
would
about
center
the
display;
and
for
bipolar
signals,
centering
the
ground
trace
Is
appropriate.)
Zeroing
the
Trigger
LEVEL
control
may
be
useful
if
the
cursor
is
positioned
out
of
the
viewing
area.
Simply
switch
the
Input
COUPLING
of
the
selected
channel
to
GND
and
switch
the
Trigger
MODE
to
AUTO
LEVEL.
Once
zeroed,
set
the
Trigger
MODE
to
NORM
so
that
the
Trigger
LEVEL
you
set
will
be
maintained.
(If
AUTO
LEVEL
Is
left
on,
the
Trigger
LEVEL
will
con-
tinue
to
follow
the
applied
signal:
ground
In
this
case.)
Use
the
Trigger
LEVEL
control
to
position
the
trigger
level
cursor
to
about
3
V
(measured
fram
the
ground
cursor).
For
the
assumed
signal,
thls
level
is
ample
to
avoid
triggering
on
the
lower
amplitude
signals
In
the
display.
For
other
waveforms,
the
user
must
determine
what
trigger
level
Is
needed
to
obtain
triggering
on
a
specific
waveform
amplitude.
Apply
the
signal
to
the
appropriate
input
channel
connector
and
set
the
Input
COUPLING
to
DC.
The
waveform
display
will
now
appear
(assuming
the
A
INTENSITY
Is
set
to
a
viewing
level),
and
it
will
be
triggered
on
the
larger
amplitude
pulses
of
the
signal,
Once
triggering
Is
obtained,
the
A
SEC/DIV
setting
may
be
set
to
a
faster
sweep
speed
to
expand
the
triggering
pulse
for
making
any
measurements
wanted,
Use of the Add Mode
With
the
VERTICAL
MODE
set
to
ADD,
the
resulting
waveform
Is
the
algebraic
sum
of
the
signals
applied
to
the
Channel
1
and
Channel
2
Inputs
(CH
1
+
CH
2).
A
plus
symbol
(+)
appears
In
the
readout
between
the
CH
1
and
CH
2
VOLTS/DIV
setting
readout
to
indicate
that
ADD
Is
active.
If
the
CH
2
INVERT
feature
Is
turned
on
(INVERT
button
lit),
the
waveform
displayed
Is
the
difference
between
the
signals
applied
to
the
Channel
1
and
Channel
2
Inputs.
Nelther
the
CH
1
nor
CH
2
waveform
needs
to
be
displayed
to
obtain
the
ADD
trace,
but
any
or
ALL
vertical
input
channels
may
be
displayed
at
the
same
time
if
wanted
by
the
user.
When
the
VOLTS/DIV
switches
of
CH
1
and
CH
2
are
both
set
to
the
same
setting,
the
total
deflection
factor
in
the
ADD
mode
Is
equal
to
the
deflec-
tlon
factor
Indicated
by
elther
VOLTS/DIV
readout.
The
t€
VOLTS
5-22
2247A
Operators
ft
Cos
a