Hameg HM303-6, Service Manual

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56
Subject to change without notice
29 RV4004: 50 μs/div time base adjustment
– Set input attenuator CH I to 0.1 V/div.
– Locate and identify RV4004 on TB-Board.
– Set time base to 50 μs/div and time base variable control
to CAL position.
– Set time mark generator to 50 μs pulse interval (f = 20 kHz)
and connect signal to CH I input.
– Move trace with X-POS. control so that the fi rst time mark
coincides with the left-most graticule line of the screen.
– Adjust RV4004 so that each time mark coincides with a
vertical graticule line.
– Rotate time base variable control to the fully ccw position
and check that more than 2.5 time marks per division are
displayed.
Incorrect Correct Incorrect 2.5 : 1 < 2.5 pulses pro div
30 RV4003: 50 ms/div time base adjustment
– Set input attenuator CH I to 0.1 V/div.
– Locate and identify RV4003 on TB-Board.
– Set time base to 50 ms/div and time base variable control
to CAL position.
– Set time mark generator to 50 ms pulse interval (f = 20 Hz)
and connect signal to
CH I input.
– Move trace with X-POS.
control so that the fi rst
time mark coincides with
the left-most graticule
line of the screen.
– Adjust RV4003 so that
each time mark coincides
with a vertical graticule line.
Correct
Incorrect Incorrect
RV4003 RV4004 CV4001 RV4005
TB-Board
RV4002 RV4001
RV4003 RV4004 CV4001 RV4005
TB-Board
RV4002 RV4001
A d j u s t m e n t P r o c e d e r e H M 3 0 3 - 6