Auxiliary
Functions
VOLTS/CM
Nine-position
switch to
select
the
desired
deflection
sensitivity.
VARIABLE
Continuously
variable
control
to
vary
the
sensitivity
between
ranges
and
to
50
volts/cm.
When
this
control
is
away
from
the
clockwise
stop
the
UNCALIBRATED
light
indicates
that
the
amplifier
is
not
calibrated.
Rear
Panel
+
GATE
Binding
post
to
supply
a
positive
pulse
for
the
duration of the
time
base.
SAWTOOTH
OUT
Binding post
to
supply
a positive-going
sawtooth, synchronized
with
the internal
time
base.
SQUARE-WAVE
CALIBRATOR
Twelve-position
switch
to
select one
of
eleven
taps
on
a precision
voltage
divider
in
the
calibrator circuit
and
to
turn
the
calibrator off.
CAL.
OUT
Coax
connector
from
the
calibrator.
POWER
On-off
switch
in
the
lead
to
the
power
transformer
and
fan.
TRIGGERING
INSTRUCTIONS
CRT
CATHODE
Binding post
to
the ert
cathode
for
the application of
intensity
modulation.
General
The
function
of
the trigger
circuit
is
to
derive
from
the
incoming
waveform
a
sharp
pulse of
suitable
amplitude
to
trigger
the
time-base
generator.
One
such
pulse
occurs
for each
cycle
of
the
incoming
waveform.
This
pulse
is
independent of
the
incoming
waveform
in
shape
and
amplitude.
The
time-base
generator
develops
the
saw
tooth
waveform
necessary
to provide a linear
time
base.
If
the STABILITY
control
is
set
for
triggered
operation,
the
time
base circuits
wait until
a
trigger pulse
is received,
at
which
time
one
sawtooth
waveform
is
produced.
After
the
sawtooth
waveform
is
completed
the
time
base
circuits
wait
for
the
next trigger
pulse
and
the
process
is
repeated.
The
following
paragraphs
describe
the
function
of the
controls
which
affect
this
operation.
Later
paragraphs
describe
specific
triggering
procedures.
Triggering Controls
Triggering
Level
In
the
Type
515/515A
the
TRIGGERING
LEVEL
control
determines
the
point
on
the
triggering
waveform
at
which
triggering
will
occur.
The
TRIGGERING
LEVEL
control
is
not
a
trigger
amplitude
or
gain
control
if
you
are
accustomed
to
this
type
of
circuit.
Instead, it is
an
amplitude
or voltage
discriminator.
If the
waveform
you
are
observing
is
centered
on
the
screen
and
the
TRIGGERING LEVEL control is
set
near
0
the
sweep
will
start as
the
waveform
passes
through
the
center
line
on
the
screen.
As
the
LEVEL
control
is turned
clockwise,
the
triggering
point
will
move above
the
center
line
on
the
screen,
and,
as
it
is
turned
counter
clockwise
the
triggering point
will
move
below
the center
line.
If
the
LEVEL
control
is
set
for a
voltage greater
than
that of the
waveform
being
observed
the
sweep
will stop.
Thus,
if
the
waveform
is
of low amplitude
the
LEVEL
control
should be
set
near
0
(or
near
the
de
level
with
DC
triggering).
The
LEVEL
control
is
used
only
in
the
AC
and
DC
positions
of
the
TRIGGER
SELECTOR
switch.
AA
Operating
Instructions
- Type
515/515A
2-5
