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42
Checking and adjusting
2. Sensitivity
- Set SK4 to position ".03 V/div.".
Turn R7 clockwise.
To BUS apply a signal of 300 mV
p
-
p
of a frequency of 1 kc/s.
- Adjust R780 in such a way that the horizontal deflection covers 10
divisions.
3. Length of the time base line
- Set SK4 to position "N\".
No input voltage on the input sockets.
Turn R7 fully anti-clockwise.
- By means of R5 adjust the spot to the centre of the screen.
- Set SK2 to position "2 msec/div".
- With R3 set at 45° from the left-hand stop, adjust the time base
generator to free-run by means of R522 (in doing so, the apparatus
must be at operating temperature).
- Adjust R746 in such a way that the time base line is symmetrical with
respect to the centre of the screen.
- Select such a value for R733 that the length of the time base line lies
between I I and 13 divisions in all positions of SK2.
- If necessary, readjust R746.
4. X shift
- Apply a sawtooth voltage to BU3.
- To BUS apply a sinusoidal voltage of a frequency of 2 kc/s and an
amplitude such that the picture height is 3 divisions (the voltage must
be symmetrical with respect to earth).
- Increase the amplitude of the input signal by a factor 10.
- Both with R5 fully anti-clockwise and fully clockwise it must be
possible to display the peaks of the sinewaves undistorted within the
graticule.
If necessary, valves B701 and B702 may be replaced and the adjustment
repeated from item El onwards.
5. Step attenuator
Check the attenuation with SK4 in the following positions (R7 fully
clockwise):
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