65
Subject to change without notice
45 Trigger Bandwidth Check
– Set time base to 0.1 μs/div, time base variable knob to CAL.
position.
– Press X-MAG. x10 pushbutton (IN position).
– Set input coupling switch CH I to DC.
– Set trigger coupling to AC.
– Press AT/NM (Automatic/Norm) pushbutton (IN position).
– Set input attenuator CH I to 5 mV/div.
– Connect a 100 MHz sine wave signal to input CH I.
– Adjust generator output for 5 mm display height.
– Turn LEVEL knob until the oscilloscope triggers.
46 External Trigger Check
– Set time base to 50 μs/div.
– Set input attenuator CH I to 0.1 V/div.
– Connect a 50 kHz sine wave signal with an amplitude of
300 mV
pp
via a 50 Ω through-terminator to input CH I
and check for 3 div display height.
– Set LEVEL to midrange position.
– Check that the Trigger-LED (TR) is ON.
– Press TRIG. EXT. pushbutton. The Trigger-LED (TR) should
now be OFF.
– Remove signal cable from input CH I and connect it to TRIG.
EXT. socket. Do not change generator settings.
– Verify that the Trigger-LED (TR) is ON.
47 Video Trigger Check
– Set CH I input coupling switch to DC.
– Connect video signal with positive sync. pulses to input
CH I.
– Set input attenuator CH I for 0.5 div display amplitude of the
sync. pulses.
– Set trigger coupling switch to TV.
– Set time base to 5 ms/div for TV frame triggering.
– Check that trigger starts with vertical sync. pulses.
– Now approx. 2.5 frames should be visible.
– Change polarity of the video signal.
– Press SLOPE pushbutton (IN position).
– Again approx. 2.5 frames should be displayed triggered.
– Set time base to 20 μs/div for TV line triggering.
– Now approx. 3 lines should be visible.
– Change polarity of video signal.
– Release SLOPE pushbutton to the OUT position.
– Again 3 lines should be displayed triggered.
Note:
The switch over from frame to line TV triggering is performed
by the time base switch. In time base settings from 0.2 s/div to
0.2 ms/div TV frame triggering is selected. Line triggering is
present from 0.1 ms/div to 0.1 μs/div.
48 Invert-Balance Check CH II
– Press CH I/II - TRIG. I/II pushbutton (IN position).
– Set attenuator CH II to 5 mV/div.
– Set input coupling CH II to GND.
– Using Y-POS.II control set trace to the horizontal centre line
of the graticule.
– Press and release the INV. pushbutton. The baseline must
not move more then 0.2 div. (2mm).
49 Variable-Balance Check CH I
– Set input coupling CH I to GND.
– Using Y-POS.I control set trace to the horizontal centre line
of the graticule.
– Turn variable gain knob through the entire range. The
baseline must not move more then 0.2 div. (2mm).
50 Variable-Balance Check CH II
– Press CH I/II - TRIG. I/II pushbutton (IN position).
– Set input coupling CH II to GND.
– Using Y-POS.II control set trace to the horizontal centre line
of the graticule.
– Turn variable gain knob through the entire range. The
baseline must not move more then 0.2 div. (2mm).
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
