Philips PM 3266 - 3.4.11. Triggering

162
3.4.
1
1.3.
Single-sweep
operation
-
Depress
push-button
A of the
display-mode
controls
{SI
)
-
Set
the
channel
A AMPL
switch
to
.2 V/DIV
and
its
vernier
to
CAL
-
Depress
push-button
MTB
of
the
X deflection
controls
(S2)
—
Set the
m.t.b.
LEVEL
control
to
mid-range
-
Set
the
m.t.b.
TIME/DIV
switch
to .1
s and
the
vernier
to CAL
—
Set
the
d.t.b.
TIME/DIV
switch
to OFF
-
Depress
push-button
A of
the
m.t.b.
trigger-source
controls
(S22)
—
Depress
push-button
0
of the
channel
A
signal-coupling
controls
-
Apply
a
signal
that
gives
a
trace
height
of
approx.
6 DIV
to input
A
—
Push
the
SINGLE
button
of
the
m.t.b.
trigger-mode
controls
—
Check
that the
NOT
TRIG'D
lamp
lights
up
—
Depress
push-button
AC of
the
channel
A
signal-coupling
controls
—
Check
that
the
trace
is
written
once
and that
the
NOT
TRIG'D
lamp
is extinghuished
at the
end of
the
sweep
—
Remove
the
input
signal.
3.4.
1 1.4.
Triggering
at
mains
frequency
—
Depress
push-button
A
of the
display-mode
controls
(SI
)
-
Depress
push-button
MTB
of the
X
deflection
controls
(S2)
—
Depress
push-button
AUTO
of the
trigger-mode
controls
—
Depress
push-button
DC
of
the
trigger-coupling
controls
—
Set the
m.t.b.
TIME/DIV
switch
to
5
ms and
its vernier
to CAL
—
Depress
push-button
EXT of the
trigger-source
controls
(S22)
—
Apply
a mains
voltage
derived
signal
to
the
channel
A input
—
Adjust the
trace
height
to
approx.
3 DIV; the
trace must
be running
-
Depress
push-button
EXT and
EXT
^
10
(S22)
simultaneously
(LINE)
—
Check
that
a stable display
can
be obtained,
using the m.t.b.
LEVEL
control
—
Remove the
input
signal.
3. 4. 1
1. 5.
Trigger slope and
level
of the d.
t.b.
—
Depress
push-button
A of the display-mode
controls
(SI
)
-
Depress
push-button
DEL’D
TB of the
X deflection controls
(S2)
—
Depress
push-button A of
the
d.t.b. trigger-source
controls
(S21
)
—
Depress
push-button
DC
of the
d.t.b. trigger-coupling
controls
-
Push
the
channel
A Y POSITION control
to
the
NORM position
—
Set the
channel
A AMPL switch
to 20
mV/DIV
and its vernier
to CAL
—
Turn
the
DELAY TIME
(
R1
)
control fully
anti-clockwise
—
Set
the
m.t.b. TIME/DIV
switch
to
20
ps and its vernier
to CAL
—
Set the
d.t.b.
TIME/DIV switch to
^0
ps and its vernier to
CAL
—
Apply
a sine-wave voltage
of 120 mVp.p, frequency
30
khlz,
to
the
channel A input
—
Centre
the display, using the POSITION
controls
—
Centre
the starting point
of the sine-wave, using
the d.t.b.
LEVEL
control
—
Check that
the starting point
of the signal
does
not move when
the SLOPE
switch is
set
from
-r
to
—
—
Push
the
SLOPE switch
to its
+
position
—
Check that
the time-base generator
starts
on
the
positive-going
part of the sine-wave
and moves
upwards
when the
d.t.b.
LEVEL potentiometer is turned clockwise
—
Pull the
SLOPE switch
to
—
position
—
Check
that the
time-base generator
starts on the
negative-going
part of the sine-wave
—
Set the channel
A
AMPL switch
to 5
mV/DIV
arid its vernier to
CAL
—
Rotate the d.t.b.
LEVEL control fully
clockwise and anti-clockwise
—
Check that
in both extreme
pxasitions the
time-base generator cuts out
—
Increase
the amplitude of
the input
signal to 1 60 mVp.p
—
Rotate the
d.t.b. LEVEL
control fully
clockwise
and anti-clockwise
-
Check that
in
both extreme
positions the
trace
remains triggered.