Subject to change without notice
22
1.2.2.1 LOAD S/R DEFAULT (S/R = SAVE/RECALL)
This overwrites all
SAVE/RECALL
memories with the following
instrument setting: Single channel operation (“Y1:500mV~”), time
base (“A:100µs”) and automatic peak value triggering with trigger
conditions ”TR:Y1/AC”.
1.2.2.2 RESTORE FACTORY DEFAULT
If inadvertently an adjustment was performed in
CALIBRATE
MENU
condition, which was not stored by
OVERWRITE
FACTORY DEFAULT
, the factory adjustments can be recalled by
this function.
1.2.2.3 OVERWRITE FACTORY DEFAULT
Attention!
Calling this function causes the factory adjustments to
be overwritten by new data. The factory adjustment then
is lost and can not be recalled by RESTORE FACTORY
DEFAULT.
This function is only intended for those cases in which
an adjustment can be performed with very expensive
”0% error” calibrators, to adjust the instrument for
optimum tolerance when operated under extreme
environmental conditions.
First Time Operation
The following text assumes that the “SAFETY” section of
this manual has been read carefully and understood.
Each time before the instrument is put into operation check that
the oscilloscope is connected to protective earth. For that reason
the power cable must be connected to the oscilloscope and the
power outlet. Then the test lead(s) must be connected to the
oscilloscope input(s). Check that the device under test is switched
off and connect the test lead(s) to the test point(s). Then switch
on the instrument and afterwards the device under test.
The oscilloscope is switched on by depressing the red
POWER
pushbutton. After a few seconds the
HAMEG
logo and the
instrument software release is displayed on the screen. As long as
the
HAMEG
logo is visible different internal checks are made.
Thereafter the instrument will revert to its last used operating mode.
If after approx. 20 seconds no trace is visible, the
AUTOSET
pushbutton should be pressed briefly. This selects the Yt mode
and medium trace and readout intensit y (please note
“AUTOSET”
). Adjust
Y-POS.I
and
X-POS.
controls to center the
baseline. Adjust
INTENS.
(intensity) and
FOCUS
controls for
medium brightness and optimum sharpness (input(s) grounded)
of the trace. The oscilloscope is now ready for use.
If the
AUTOSET
function was not used and only a spot appears
(
CAUTION! CRT phosphor can be damaged
), reduce the
intensity immediately and check that the XY mode is not selected
(XY not displayed in the readout).
To obtain the maximum life from the cathode-ray tube, the
minimum intensity setting necessary for the measurement in
hand and the ambient light conditions should be used.
Particular care is required when a single spot is displayed, as a
very high intensity setting may cause damage to the fluorescent
screen of the CRT. Switching the oscilloscope off and on at short
intervals stresses the cathode of the CRT and should therefore
be avoided.
The instrument is so designed that even incorrect operation will
not cause serious damage.
Trace Rotation TR
In spite of Mumetal-shielding of the CRT, effects of the earth’s
magnetic field on the horizontal trace position cannot be
completely avoided. This is dependent upon the orientation of
the oscilloscope on the place of work. A centered trace may not
align exactly with the horizontal center line of the graticule. A
few degrees of misalignment can be corrected by a potentiometer
accessible through an opening on the front panel marked TR.
Probe compensation and use
To display an undistorted waveform on an oscilloscope, the probe
must be matched to the individual input impedance of each
vertical amplifier.
For this purpose a square wave signal with a very fast rise time
and minimum overshoot should be used, as the sinusoidal
contents cover a wide frequency range.
The built-in calibration generator provides a square wave signal
with a ver y fast rise time (<4ns), and switch-selectable
frequencies of approx. 1kHz and 1MHz from the output socket
below the CRT screen. As the square wave signals are used for
probe compensation adjustments, neither the frequency accuracy
nor the pulse duty factor are of importance and therefore not
specified.
The output provides 0.2Vpp ±1% (tr <4ns) for 10:1 probes. When
the Y deflection coefficient is set to 5mV/div, the calibration
voltage corresponds to a vertical display of 4 divisions (10:1
probe).
The output socket has an internal diameter of 4.9mm to
accommodate the internationally accepted shielding tube
diameter of modern Probes and F-series slimline probes. Only
this type of construction ensures the extremely short ground
connections which are essential for an undistorted waveform
reproduction of non-sinusoidal high frequency signals.
Adjustment at 1kHz
The C-trimmer adjustment (low frequency) compensates the
capacitive loading on the oscilloscope input. By this adjustment,
the capacitive division assumes the same ratio as the ohmic
voltage divider to ensure the same division ratio for high and low
frequencies, as for DC. (For 1:1 probes or switchable probes set
to 1:1, this adjustment is neither required nor possible). A baseline
parallel to the horizontal graticule lines is essential for accurate
probe adjustments. (
See also “Trace rotation TR”
).
Connect the probes (Types
HZ51
,
52
,
54
, or
HZ36
) to the CH I
input. Set the deflection coefficient to 5mV/div and the input
coupling to DC. The time deflection coefficient should be set to
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