31
Subject to change without notice
Table of Content
A: Test Instruments required
B: Basic Settings
D: Checks
1. Trace Rotation
2. CRT minimum intensity
3. Focus symmetry
4. Astigmatism
5. CH I: Y Accuracy
6. CH II: Y Accuracy
7. CH I: 100 Hz square wave
8. CH II: 100 Hz square wave
9. CH I: Variable Balance
10. CH II: Variable Balance
11. CH I: Y-MAG. x5 Balance
12. CH II: Y-MAG. x5 Balance
13. CH II: INVert Balance
14. ADD Balance
15. CH I: Attenuator
16. CH II: Attenuator
17. Y-Final Amplifi er
18. CH I: 5 mV/div Y-Amplifi er Bandwidth
19. CH II: 5 mV/div Y-Amplifi er Bandwidth
20. CH I: 1 mV/div Y-Amplifi er Bandwidth
21. CH II: 1 mV/div Y-Amplifi er Bandwidth
22. X-Magnifi cation x1
23. Time Base
24. X-Magnifi cation x10
25. X-Magnifi cation x10 linearity
26. X-Gain in XY-Mode
27. XY mode X-Amplifi er Bandwidth
28. Trigger sensitivity
29. CH I: DC-Triggering
30. CH II: DC-Triggering
31. Trigger Bandwidth
32. Extern Trigger Sensitivity
33. Extern Trigger Bandwidth
34. Video Trigger
35. Line Trigger
36. Trigger Filter Check
37. Component-Tester
38. Calibrator Output
A: Test Instruments required
1) Fast rise time (
<
1ns) square wave generator: 10 Hz to
1 MHz (switchable in decades), 25 mV
pp
output at 50
Ω
through termination, overshoot less than 1% of signal
amplitude (e.g. HZ620).
2) Constant amplitude sine wave generator, 20 Hz – 500 MHz,
output 5 mV – 5 V into 50
Ω
preferably with 20dB attenuation
(e.g. HM 8134).
3) Amplitude Calibrator with 1 kHz square wave output and
600
Ω
impedance, rise time faster than 1 ns. Output voltage
10 mV
pp
– 40 V
pp
in 1 – 2.5 - 5 sequence for 5 divisions display
amplitude (e.g. HZ620) with the exception of 40 V
pp
. Accuracy
0.1% or better.
4) Time mark generator from 10 ns/div to 1 s/div. Output min.
10 mV into 50
Ω
(e.g. HZ620).
5) Pre-attenuator 2:1 (1M
Ω
parallel with 10-25 pF), e.g.
HZ20.
6) 2
50
Ω
BNC through termination, e.g. HZ22.
7) 2 BNC-cables, 50
Ω
, e.g. HZ34.
8) 50
Ω
6 dB splitter with 2 outputs.
9) Video signal generator with positive and negative signal
output.
B: Basic Settings
Before starting each adjustment procedure, set the oscilloscope
to the following basic settings:
– POWER pushbutton pressed (IN position).
– AC/DC input coupling pushbuttons CH I and CH II pressed
(IN position).
– All other pushbuttons (Out Position!).
– Rotate the three variable controls (TIME/DIV. and VOLTS/
DIV.) to their (calibrated) detent positions.
– Set TIME/DIV. switch to 0.2 ms/div.
– Set both VOLTS/DIV switches to 5 mV/div.
– Rotate the HOLD OFF knob fully counter clockwise.
– Set trigger coupling lever to AC.
– Set all other controls to their midrange positions.
If different settings are required, it is specifi ed in each adjust-
ment.
C: Checks
Do not check the instrument until the normal operating temperature
is reached, after a minimum warm up time of 30 minutes.
1. Trace Rotation Check
– Press GD pushbutton CH I (IN position).
– Turn TRACE ROTATION using a small screwdriver to ad-
just the baseline exactly parallel to a horizontal line of the
graticule.
– Set baseline with Y-POS. I knob to the horizontal centre line
of the graticule.
– Turn TRACE ROTATION to fully clockwise and counter
clockwise position and check the range of inclination of
the baseline is at least 1mm at left and right horizontal
endpoints of the graticule.
– Turn TRACE ROTATION to adjust baseline to be displayed ex-
actly parallel to the horizontal centre line of the graticule.
2. CRT minimum intensity
– Set INTENS control to fully counter clockwise position.
– Press X-Y pushbutton (IN position).
– Check that the dot has just disappeared.
– Release XY pushbutton.
Performance Check HM303-6
P e r f o r m a n c e C h e c k H M 3 0 3 - 6
