Philips PM 3266 - 3.4.4. Power supply

149
-
Set
the
mains
input
voltage
to
170
V
-
Check
that
the
voltage
on
the
positive
pole
of
Cl 831
is
+12,7
V
±
100
mV;
if
necessary,
readjust
potentiometer
R1827
on
the
power
supply
board.
3.4.4.3.
Cathode
voltage
(unit
11)
-
Check
that
the
voltage
on the
collector
of V2073
(unit
1
1)
on
the
Z
amplifier
board
is
85 V ±
3 V
-
If
necessary,
readjust
potentiometer
R2123
on the
Z amplifier
board.
3.4.5.
Calibration
socket
If
necessary,
check
the supply
voltages
first, refer
to section
(3.4.4.).
—
Check
the
calibration
square
wave
on
irregularities
—
Check
that
the
amplitude
of the
CAL
voltage is
3 V
±
1
%;
if
necessary,
readjust
potentiometer
R1906
on the
calibration
board
-
Check
that
the
frequency
of
the
CAL voltage is
2
kHz, ±
2 %
—
Check
that
the
CAL
current
is 6 mA ±
1 %.
3.4.6.
Cathode-ray
tube circuit
3.4.6.
1.
Focus
and
horizontal
intensity.
—
Check
that
the
controls
occupy the
positions indicated
in
section 3.4.3.
—
Depress
pushbutton
A of
the vertical
display mode
selector (SI
).
-
Apply
a sine-wave
signal
with the
frequency of
100 kHz
to input
A.
—
Adjust
the trace
height
to 6 DIV,
using the AMPL/DIV
switch and vernier
control.
—
Set the MAIN
TIME/DIV
switch and the
LEVEL
control to such
a position that
several complete
cycles
are
displayed.
—
Set
the
INTENS
control for
normal
brightness.
—
Adjust
trimming
potentiometer R19
to optimal focusing in vertical
direction.
R19 can
be reached via
one
of the
ventilation
holes in
the left
side of the instrument.
The focusing
in horizontal
direction
is
adjustable
by means of R17 on the
front
panel of the instrument.
—
Increase the
trace brightness
by means of
the INTENS control.
—
Check
if the trace
stays well focused. If
not readjust
R19 somewhat.
—
Remove
the input signal.
—
Adjust R2102
on the
Z-amplifier unit
to maximum
equality of the trace in horizontal
direction.
3.
4. 6. 2.
Trace
ro ta tion
—
Depress
push-button
A
of the
display-mode
controls (SI
)
—
Depress
push-button
MAIN TB of the X-deflection
controls
(S2)
—
Centre
the time-base
line using the
POSITION controls
—
Check that
the time-base
line runs exactly
in
parallel
with the horizontal
graticule lines; if
necessary,
readjust
the
TRACE ROT control R15.
This control
can be reached via one of the
ventilation holes on
the left side of
the
instrument.
3.4.
6. 3.
Orthogonality
(unit
26)
—
Depress
push-button
ALT
of the
display-mode
controls
(SI
)
—
Depress
push-button
MAIN
TB of the
X deflection
controls
(S2)
—
Depress
push-button
0
of
the channel
A signal-coupling
controls
—
Set
the MAIN
TIME/DIV
switch
to
1 ms
and
the
DEL'D
TB switch to
5
jus
—
Set the channel
B
AMPL
switch
to
5
mV/DIV
and
its vernier
control
to
CAL
Apply
a
sine-wave
voltage
of 120
mV, frequency
100
kHz, to input
B
—
Centre the
intensified
part
of the trace,
using the
DELAY
TIME
control (R1
)
—
Centre the
channel
A time-base
line,
using the channel
A POSITION
potentiometer
-
Check
that
the
angle
between the
horizontal
and
vertical line
is 90°,
see
Fig.
3.24. If
necessary,
readjust
R1737
on the
X-amplifier
unit.
3.4.6.4. Geometry
(~
barrel
and
pin cushion
distortion)
—
Depress
push-button
A of
the
display-mode
controls
(SI
)
-
Depress
push-button
MAIN
TB of the
X deflection controls
(S2)