Hameg CombiScope HM1508-2 Service Manual

29
Subject to change without notice
Some checks require the presence of software adjustment
menus. To enter these menus:
1. Press the PROBE ADJ pushbutton below the CRT to display
the Utilities menu.
2. Switch COMP. TESTER On.
3. Press the AUTO/CURSOR-MEASURE pushbutton and the
SETTINGS pushbutton at exactly the same time to activate
the Settings Adjust menu.
D Checks
1. Trace Rotation Check
– Press FOCUS TRACE MENU pushbutton on the front panel
to open the “Int. Knob” menu.
– Select “Trace Rot.”.
– Set baseline with POSITION 1 to the horizontal centre line
of the graticule.
– Turn INTENS knob to adjust baseline exactly parallel to the
horizontal centre line of the graticule.
2. CH1 5 mV/div: 100 Hz Square Wave
– Connect a 25 mVpp, 100 Hz square wave signal via 50Ω cable
and 50Ω through terminator to input CH 1 (HZ620 without
50 ohm Terminator).
– Check that DC input coupling is selected.
– Set time base to 2 ms/div.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Check that two straight lines are displayed.
3. CH1 2 mV/div: 100 Hz Square Wave
– Connect a 10 mVpp, 100 Hz square wave signal via 50Ω cable
and 50Ω through terminator to input CH 1 (HZ620 without
50 ohm Terminator).
– Set input attenuator CH 1 to 2 mV/div
– Check that DC input coupling is selected.
– Set time base to 2 ms/div.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Check that two straight lines are displayed.
4. CH2 5 mV/div: 100 Hz Square Wave
– Press VERT/XY pushbutton to call the Vertical menu.
– Press CH 2 function key to select CH 2 mode.
– Connect a 25 mVpp / 100 Hz square wave signal via 50Ω
cable and 50Ω through terminator to input CH 2 (HZ620
without 50 ohm Terminator).
– Check that DC input coupling is selected.
– Set time base to 2 ms/div.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Check that two straight lines are displayed.
5. CH2 2 mV/div: 100 Hz Square Wave
– Press VERT/XY pushbutton to call the Vertical menu.
– Press CH 2 function key to select CH 2 mode.
– Connect a 10 mVpp, 100 Hz square wave signal via 50Ω cable
and 50Ω through terminator to input CH 2 (HZ620 without
50 ohm Terminator).
– Set input attenuator CH 2 to 2 mV/div
– Check that DC input coupling is selected.
– Set time base to 2 ms/div.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Check that two straight lines are displayed.
6. CH 1: Attenuator Compensation
6.1 CH 1 Input Capacitance Adaptation
– Connect a 50 mVpp, 1 kHz square wave signal via a 2:1 pre-
attenuator (1MΩ with parallel C-trimmer) to input CH 1.
– Check that DC input coupling is selected.
– Set time base to 500 μs/div.
– Check for 5 divisions signal height at 5 mV/div. attenuator
setting.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Adjust C-trimmer in 2:1 pre-attenuator for 2 parallel,
straight lines.
– Do not change the C-trimmer settings until item 6 is fi ni-
shed.
6.2 CH 1 10:1 Attenuator Compensation
– Set attenuator CH 1 to 50 mV/div.
– Increase the calibrator output voltage for 5 division signal
height.
– Check that 2 parallel, straight lines are displayed.
6.3 CH 1 100:1 Attenuator Compensation
– Set attenuator CH 1 to 500 mV/div.
– Increase the calibrator output voltage for 5 division signal
height.
– Check that 2 parallel, straight lines are displayed.
7. CH 2: Attenuator Compensation
7.1 CH 2 Input Capacitance Adaptation
– Connect a 50 mVpp, 1 kHz square wave signal via a 2:1 pre-
attenuator (1MΩ with parallel C-trimmer) to input CH 2.
– Check that DC input coupling is selected.
– Set time base to 500 μs/div.
– Check for 5 divisions signal height at 5 mV/div. attenuator
setting.
– Press TRIGGER FILTER pushbutton and select Slope:
Both.
– Adjust C-trimmer in 2:1 pre-attenuator for 2 parallel,
straight lines.
– Do not change the C-trimmer settings until item 7 is fi nis-
hed.
7.2 CH 2 10:1 Attenuator Compensation
– Set attenuator CH 2 to 50 mV/div.
– Increase the calibrator output voltage for 5 division signal
height.
– Check that 2 parallel, straight lines are displayed.
7.3 CH 2 100:1 Attenuator Compensation
– Set attenuator CH 1 to 500 mV/div.
– Increase the calibrator output voltage for 5 division signal
height.
– Check that 2 parallel, straight lines are displayed.
8. CH 1: Y Accuracy
The accuracy reading should always be performed in the
following way:
– Set the square wave bottom on a horizontal graticule line and
read the height in the top position in the screen centre.
– Calculate the deviation in respect to the specifi cations.
(5% error of 5 div. (50 mm) height means that the acceptance
range is from 47.5 mm to 52.5 mm; 3% means ±1.5 mm)
Performance Check HM1508-2

Hameg CombiScope HM1508-2 Specifications

General

Brand	Hameg
Model	CombiScope HM1508-2
Category	Measuring Instruments
Language	English