Philips PM 3266 - Page 155

160
3.4.
10.11.
Alternate
mode
—
Depress
push-button
ALT of the
display-mode
controls
—
Set the
m.t.b.
fl ME/D
IV switch
to 1
0
ps
—
Check
that there
are
two
time-base
lines
displayed
which
can
be
shifted
in
relation
to each
other, using
the Y
POSITION
controls
-
Set the
m.t.b.
TIME/DIV
switch
to .1 s
—
Check
that
the
channels
are
switched
over
after every
sweep
of the
time-base
voltage.
3.4.
10. 12.
Square-wave
response
trigger
view
via
channel
A (B)
(Unit
12)
—
Depress
push-button
TRIG
VIEW
of the
display-mode
controls
—
Push
the
Y
POSITION
controls
to
the
NORM
position
Depress
push-button
DC of
the
channel
A and
B
signal-coupling
controls
-
Set
both
AMPL
switches
to 10 mV/DIV
and their
verniers
to
CAL
—
Depress
push-button
MTB
of
the
X deflection
controls
—
Depress
push-button
A (B)
of
the m.t.b.
trigger-source
controls
—
Set the
m.t.b.
TIME/DIV
switch
to a suitable
position
—
Set
the
d.t.b.
TIME/DIV
switch
to
OFF
-
Apply
a
square-wave
voltage
of
60
mV,
frequency
2 kHz,
rise time
1 ns,
to
the
channel
A (B)
input
-
Check
that
the pulse
top is
straight
and
the rise time
as short
as possible
-
Increase
the
repetition
rate
of the
input
signal
to 30 kHz
-
Check
that
the
pulse
top is
straight within
5
% and
that the
rise time
is
as short
as possible, if
necessary,
select
a different
value
for
resistors
R255D, R254D
(R255C,
R254C)
and
capacitors
C400,
C405
(C450
C455)
on
the
intermediate
amplifier
board
-
Increase
the
repetition
rate of
the
input
signal
to 100 kHz
-
Check
that the
pulse
top is
straight within
5 %
and
that
the rise time
is
as short
as
possible; if
necessary,
select
a different
value
for
resistor R253D
(R253C)
and capacitors
C410
(C460)
on the
intermediate
amplifier
board
—
Remove
the
input
signal.
3.4. 10. 13.
Bandwidth
trigger
view via
channel A
IB)
—
Depress
push-button
TRIG
VIEW of the
display-mode
controls
(SI
)
—
Push the
Y
POSITION
controls
to NORM position
—
Set both AMPL
switches
to 10 mV/DIV and their verniers
to
CAL
—
Depress
push-buttons AC of
the signal-coupling
controls
—
Depress
push-button
MTB of the
X deflection controls
(S2)
—
Push the
TB
MAGN
switch
to
x1
—
Depress
push-button
AUTO of the
trigger-mode controls
—
Depress
push-button HF of
the
m.t.b. trigger-coupling controls
—
Depress
push-button
A (B)
of
the m.t.b.
trigger-source controls
(S22)
—
Set the m.t.b. TIME/DIV
switch
to 2 ms and its vernier
to
CAL
-
Set the
d.t.b. TIME/DIV
switch
to
OFF
—
Apply
a
sine-wave
voltage of 60 mVp.p, frequency
2 MHz,
to
the channel
A (B) input
—
Check
that the
trace height is
6 DIV
—
Increase
the frequency
of the input
voltage
to 50
MHz
—
Check that the
trace height
is
at
least
4,2
DIV
—
Remove
the
input signal
3.4.10. 14.
Bandwidth trigger
view via
external input
—
Depress
push-button
TRIG VIEW of the display-mode
controls
(SI)
—
Depress
push-button
MTB of the
X
deflection
controls
(S2)
—
Depress
push-button
EXT of the m.t.b. trigger-source
controls
(S22)
—
Apply a sine-wave
voltage of
600 mVp.p, frequency
2
MHz,
to
the m.t.b.
EXT input
—
Check
that the
trace height
is 6 DIV
—
Increase
the frequency
of
the
input signal
to 50
MHz
—
Check
that
the
trace
height
is
at least
4,2
DIV
—
Remove the
input signal.