Philips PM3208 - 5.3.11 Vertical x5 MAG Gain; 5.3.12 Channel B Invert Adjustment

5
PERFORMANCE
CHECK
AND
ADJUSTMENT
PROCEDURE
5-7
ADJUSTMENT Adjust VR53 (""CH1G" - VERT PCB) for 5 divisions height.
After adjustment, check the channel A variable gain control.
With the control in minimum position, the waveform must
decrease to less than 2 divisions.
Switch back to position CAL.
REQUIREMENTS Check all positions of the AMPL/DIV switch.
input voltage AMPL/DIV setting display +3 %
20 mV 5 mV 4 div
50 mV 10 mV 5 div
0,1 V 20 mV 5 div
0,2 V 50 mV 4 div
0,5V 0,1 V 5 div
1V 0,2 V 5 div
2V 0,5V 4 div
5V 1V 5 div
10 V 2V 5 div
20 V 5V 4 div
SETTING Vertical mode - B
Channel B coupling - DC
Channel B AMPL/DIV - 0,1 V
Variable control in CAL.
Apply a 1 kHz square-wave signal to channel B, peak to peak
amplitude 500 mV.
ADJUSTMENT Adjust VR153 ("CH2G" - VERT PCB) for 5 divisions height.
After adjustment, check the channel B variable gain control.
With the control in minimum position, the waveform must
decrease to less than 2 divisions.
Switch back to position CAL.
REQUIREMENTS Check all AMPL/DIV steps of channel B as specified for A.
5.3.11. Vertical x5 MAG gain
TEST EQUIPMENT Square-wave calibration generator
SETTING Vertical mode - A
Channel A coupling - DC
Channel A AMPL/DIV - 0,1 V
Pull the channel A variable control into x5 position.
Apply a 1 kHz square-wave signal to channel A, peak to peak
amplitude 0,1 V.
ADJUSTMENT Adjust VR30 ("x5G" - VERT PCB) for a waveform of 5 divisions.
SETTING Repeat for channel B.
ADJUSTMENT Repeat for channel B by means of VR130.
5.3.12 Channel B invert adjustment
TEST EQUIPMENT NO
SETTING Vertical mode - DUAL
Set for two straight lines A and B and place the two position knobs
in centre position (12 o’clock). Check whether the knobs are
correctly mounted at the axis (well centered).
ADJUSTMENT Adjust VR148 ("POS CENT" - VERT PCB) in that way, that trace B
does not move when switching the position knob to INVERT.
After
that,
adjust
VR332
for
coincidence
of
trace
B
and
the
X-axis
the
graticule.
After
that,
adjust
VR48for
coincidence
of
trace
A
and
the X-axis of the graticule.
5.3 PERFORMANCE CHECK AND ADJUSTMENT PROCEDURE