Philips PM 3266 - 3.4.7. Balance adjustments

152
-
Apply
a sine-wave
voltage
of
120
mV,
frequency
1
MHz,
to input
A
-
Centre
the
display,
using
the
channel
A
POSITION
control
—
Shift
the
starting
point
of the
sine-wave
to
the
central
horizontal
graticule
line,
using
the
d.t.b.
LEVEL
potentiometer.
-
Depress
push-button
DC of
the
d.t.b.
trigger-coupling
controls
-
Check
that
the
starting
point of
the
sine-wave
remains
in the
centre
of
the
screen;
if
necessary,
readjust
potentiometer
R422
on
the
intermediate
amplifier
board.
—
Depress
push-button
B of
the
display-mode
controls
{SI
)
-
Set the
channel
B
AMPL
switch
to 20
mV/DIV
and
its
vernier
to
CAL
—
Depress
push-button
HF
of
the
d.t.b.
trigger-coupling
controls
-
Depress
push-button
B of
the
d.t.b.
trigger-source
controls
(S21
)
-
Apply
a sine-wave
voltage
of
120
mV,
frequency
1
MHz,
to input
B
-
Centre
the
display,
using
the
channel
B POSITION
control
—
Shift
the
starting
point
of the
sine-wave
to
the
central
horizontal
graticule
line,
using
the
d.t.b.
LEVEL
control.
—
Depress
push-button
DC of
the
d.t.b.
trigger-coupling
controls
-
Check
that the
starting
point
of the
sine-wave
remains
in the
centre
of
the
screen;
if necessary,
readjust
potentiometer
R472
on the
intermediate
amplifier
board
—
Remove
the
input
signal,
3.4.
7.8. Y
Position
correction
(unit
13)
-
Depress
push-button
A of the
display-mode
controls
(SI
)
-
Depress
push-button
MAIN
TB of
the
X deflection
controls
(S2)
—
Set the
vertical
POSITION
potentiometer
to
mid-p)osition
—
Short-circuit
the input
of
the delay
line
on the
intermediate
amplifier
board
-
Check
that
the time-base
line
is
displayed
exactly
in the
centre
of the
screen; if
necessary,
readjust
potentiometer
R658
on the final
Y
amplifier
board.
3.4.
7.9.
TB
MAGN
balance
(unit 8)^
-
Depress
push-button
MAIN
TB of the
X deflection
controls
(S2)
-
Move
the
starting
point of
the time-base
line
to the centre
of the
screen,
using the
X POSITION
control
—
Check
that the
starting
point
does
not
move
when the
TB
MAGN
control is
operated;
if necessary,
readjust
potentiometer
R1749
on
the
time-base
board.
3.4.8. Time-base
generators
3.4.8.
1. Main time-base
time coefficients
(unit
8)
—
Depress
push-button
A of the
display-mode
controls
(SI
)
-
Depress
push-button
MAIN
TB of
the
X
deflection
controls
(S2)
—
Depress
push-button
AUTO of the
trigger-mode
controls
(S8)
—
Set the
d.t.b.
TIME/DIV
switch
to
OFF
and its vernier
to
CAL
—
Depress
push-button
DC of the
m.t.b. trigger-coupling
controls
—
Depress
push-button
A of the
m.t.b.
trigger-source controls
(S22)
—
Set the
channel
A
AMPL switch
to .1 V/DIV and its
vernier
to CAL
—
Depress
push-button
DC of the channel
A signal-coupling
controls
—
Apply
a
time-marker
signal
of
600
mV,
pulse repetition
rate 1 ms,
to
the
channel
A input
—
Push the
TB MAGN switch
to x1
—
Set the
m.t.b.
Tl ME/DI
V
switch
to 1 ms and its
vernier
to
CAL
—
Check
that the pilot lamps
x1 0
and time-base
UNCAL
are
off
—
Check
that the centre
8 cycles have
a total width of
8 DIV; if necessary,
readjust
potentiometer R1709
on the time-base
board
—
Set the m.t.b.
TIME/DIV switch
to
5
ms
—
Change the
repetition
rate of the
input signal
to
5
ms
—
Check that
the centre
8
cycles have
a
total width
of
8
DIV; if necessary,
readjust
potentiometer R913
on
the
time-base
board
—
Set the
m.t.b. TIME/DIV
switch
to
1
jUS
—
Change
the repetition
rate of the input signal
to
1
/ns.
—
Check that the centre
8
cycles
have
a
total width of
8
DIV;
if necessary, readjust
potentiometer
R911
on
the time-base
board.