32
Subject to change without notice
3. Focus symmetry
– Press X-Y pushbutton (IN position).
– Turn the INTENS knob clockwise until the dot is display-
ed.
– Turn the FOCUS knob fully clockwise and counter clockwise
and check for equal spot size in both (cw and ccw) condi-
tions, so that the focus point is in midrange position.
4. Astigmatism
– Connect a 1MHz square wave signal with 25mV
pp
at 50
Ω
(HZ22) to input CH I.
– Set time base to 0.1 μs/div.
– Adjust FOCUS control for optimum sharpness.
– Turn FOCUS control a few degrees clockwise and counter
clockwise and check that slope and top beam diameter is
always sharp (focused).
5. CH I: Y Accuracy
The accuracy reading should always be performed in the following
way.
A: Set the square wave bottom on a horizontal graticule line
and check the height of the square wave top at the (hori-
zontal) screen centre.
B: Calculate the deviation in respect to the specifi cations.
A 5% error of 5 div. (50 mm) height means that the ac-
ceptance range is from 47.5 mm to 52.5 mm; 3% means
±1.5 mm)
– Check that input coupling CH I is set to DC.
– Check that CH I variable gain knob is set to CAL. position.
– Set time base to 0.5 ms/div.
5.1 CH I 1 mV/div (5% accuracy)
– Set attenuator CH I to 5 mV/div.
– Press Y-MAG x5 pushbutton (IN position).
Note:
5 mV/div in combination with Y-MAG x5 results in 1 mV/
div.
– Connect a 5 mV
pp
(accuracy ±0.1%), 1 kHz square wave signal
via 50
Ω
cable to input CH I.
Note:
If HZ620 is used, the minimum voltage is 10 mV without 50
Ω
terminator. As the HZ620 internal resistor is 50
Ω
, connect
a 50
Ω
through resistor at the oscilloscope input, to reduce
the input voltage to 5 mV
pp
.
For 0% error the signal height is 5 div.
Note:
If HZ620 is used in combination with a 50
Ω
through termi-
nator, please remove it as it is no longer required in the
following checks.
Continue with item 5.2
5.2 CH I 2 mV/div (5% accuracy)
– Set attenuator CH I to 10 mV/div.
Note:
10 mV/div in combination with Y-MAG x5 results in 2 mV/
div.
– Connect a 10 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
– Press Y-MAG x5 pushbutton to release it (OUT position).
Continue with item 5.3
5.3 CH I 5 mV/div (3% accuracy)
– Set attenuator CH I to 5 mV/div.
– Connect a 25 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.3.1
5.3.1 Variable Gain 2.5:1
– Check that the signal display height is 5 division.
– Turn channel 1 VAR. 2.5:1 knob fully counter clockwise.
– Check that the signal height is less 2 division.
– Turn channel 1 VAR. 2.5:1 knob fully clockwise to its calib-
rated detent.
Continue with item 5.4.
5.4 CH I 10 mV/div (3% accuracy)
– Set attenuator CH I to 10 mV/div.
– Connect a 50 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.5.
5.5 CH I 20 mV/div (3% accuracy)
– Set attenuator CH I to 20 mV/div.
– Connect a 100 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.6.
5.6 CH I 50 mV/div (3% accuracy)
– Set attenuator CH I to 50 mV/div.
– Connect a 250 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.7.
5.7 CH I 100 mV/div (3% accuracy)
– Set attenuator CH I to 100 mV/div.
– Connect a 500 mV
pp
(accuracy ± 0.1%), 1 kHz square wave
signal via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.8.
5.8 CH I 200 mV/div (3% accuracy)
– Set attenuator CH I to 200 mV/div.
– Connect a 1 V
pp
(accuracy ± 0.1%), 1 kHz square wave signal
via 50
Ω
cable to input CH I.
– For 0% error the signal height is 5 div.
Continue with item 5.9.
5.9 CH I 500 mV/div (3% accuracy)
-Set attenuator CH I to 500 mV/div.
-Connect a 2.5 V
pp
(accuracy ± 0.1%), 1 kHz square wave signal
via 50
Ω
cable to input CH I.
-For 0% error the signal height is 5 div.
Continue with item 5.10.
P e r f o r m a n c e C h e c k H M 3 0 3 - 6