Philips PM32671 Service Manual page 92

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5.5.7. Time-base generators
NOTE: Before starting the adjustment of the time-base generators and the delay time multiplier add a 1 . 8 M a
5.5.7.1. Main time-base time coefficients
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Set the controls as indicated in fig. 4.1.
- Set the AMPL/DIV switch S9 to 0.5V.
- Set the MTB TIME/DIV switch S15 to Ips.
- Apply a time-marker signal of
- Check that the centre
- Pull the X MAGN switch
- Check if the MAGN led B2 lights up.
- Apply a time-marker signal, pulse repetition rate 0 . 1 ~ to input X2 (A).
- Check that the centre
- Push the X MAGN switch
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Set the MTB TIME/DIV switch S15 to O.lms.
- Apply a time-marker signal, pulse repetition rate O.lms, to input X2 (A).
- Check that the centre
- Set the MTB TIME/DIV switch S15 to 10ms.
- Apply a time-marker signal, pulse repetition rate IOms, to input X2 (A).
- Check that the centre
- Check the other positions of the TIME/DIV switch S15, using the appropriate input signals, tolerances
+/- 3%.
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Check that the trace-length in all TIME/DIV positions is
- Set the TIME/DIV switch S15 to Ips.
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Apply a time-marker signal, pulse repetition rate
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Check that the control range of the continuous control R10 lies between 1 :2.6 and 1 :3.
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Check that the UNCAL led lights up when the continuous control R10 is not in CAL position.
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Set the continuous control R10 in CAL position.
5.5.7.2. X position range
- Set the MTB TIME/DIV switch S15 to Ims.
- Apply a time-marker signal, pulse repetition rate IOms, to input A.
- Check that the two displayed marker pulses can be horizontally shifted over a range of 10 div.
- Pull the X MAGN control
- Check that the two time-marker pulses can be horizontally shifted over a range of 100 div.
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Depress the X MAGN control S7.
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Set the MTB TIME/DIV switch S15 to 0.lps.
- Apply a time-marker signal, pulse repetition rate lops, to input X2 (A).
- Turn the HOLD OFF control R11 counter clockwise.
- Check if the intensity of the displayed signal suddenly decreases.
- Set the TIME/DIV swith S15 to lops.
- Apply a time-marker signal, pulse repetition rate 0.1 ms, to input X2 (A).
- Turn the HOLD OFF control control R11 counter clockwise.
- Check if the intensity of the displayed signal suddenly decreases.
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Set the TIME/DIV switch S15 to 5ms.
- Apply a time-marker signal, pulse repetition rate 0.1 sec, to input X2 (A).
- Turn the HOLD OFF control R11 counter clockwise.
- Check if the number of sweeps suddenly decreases (longer HOLD OFF time).
- Set the HOLD OFF control R11 fully clockwise.
resistor ford. nr. 4822 63 194) across R371 on the time-base (unit 2). This compensates for sweep
time inaccuracies at high ambient temperatures.
8 cycles have a total width of 8 div; if necessary readjust R1384 (fig. 5.1
S7 (XIO).
8
cycles have a total width of 8 div; if necessary readjust R1381 (fig. 5.1
S7.
8 cycles have a total width of
8 cycles have a total width of 8 div; if necessary readjust R347 (fig.5.1.).
S7 (XIO).
8 div; if necessary readjust R348 (fig. 5.1
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to input X2 (A).
5-2 I
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.).