Hameg HM 303-4, Руководство по обслуживанию

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Subject to change without notice
42
Set input coupling CH I to GD.
Remove signal cable from input CH I and connect it to TRIG.INP. socket. Do not change
generator settings.
Now the Trigger-LED should be ON again.
(41) Video Trigger Check.
Set CH I input coupling switch to DC.
Connect video signal with positiv sync. pulses to input CH I.
Adjust input attenuator switch CH I for 1 div display amplitude of video signal.
Set time base to 5ms/div ( time base
≥
1ms/div = frame triggering).
Set trigger coupling switch to TV.
Check that trigger starts with vertical sync. pulses.
Now approx. 2.5 frames should be visible.
Change polarity of video signal.
Press SLOPE pushbutton (in!).
Again approx. 2.5 frames should be displayed triggered.
Set time base to 20µs/div ( time base range 0.5ms/div - 0.1µs/div = line triggering).
Recheck trigger SLOPE pushbutton procedure, using video signal with polarity change.
Note: Note: Note: Note: Note: Invert pushbutton does not affect trigger polarity.