33
Subject to change without notice
C o n t r o l s a n d R e a d o u t
button illuminated. The INTENS knob
2
then can be used for
manual selecting the dividing ratio of the applied probe. If no
probe is applied “*1” should be selected.
28
VERT/XY
(pushbutton)
This pushbuttones the ”Vertical“ menu on/off. This menu allows
to select the operating modes of the vertical amplifi ers.
28.1
CH1
If CH1 is selected only CH1 will be turned on, the mode is Yt.
Also the readout will only display the parameters of CH1 (sen-
sitivity, inverted/not inverted, coupling, input impedance and
bandwidth limit).
Although CH2 will not appear in the readout it may be used e.g.
as a trigger input. Its controls are active but are not shown.
28.2
CH2
If CH2 is selected only CH2 will be turned on, the mode is Yt.
Also the readout will only display the parameters of CH2 (sen-
sitivity, inverted/not inverted, coupling, input impedance and
bandwidth limit).
Although CH1 will not appear in the readout it may be used e.g.
as a trigger input. Its controls are active but are not shown.
28.3
DUAL trace alt./chop
In dual trace mode both channels are turned on and the parame-
ters of both are shown in the readout. Between the sensitivity in-
dications there is an indication whether alternate ”alt.“ or chopped
”chp“ mode is active. Normally, the mode will be automatically set
by the time base speed selection, but it may be directly set using
the function pushbutton. For time base speeds of 500 ms/cm to
500 μs/cm chopped will be used, from 200 μs/cm to 50 ns/cm
alternate. This refers to unmagnifi ed time bases.
Alternate is the preferred mode, at any time one channel is dis-
played for a full sweep, after each sweep the other channel has
its turn. At slow sweep speeds this will cause annoying fl icker, at
still slower ones the channel switching becomes visible. Here, the
chopped mode steps in, both channels are switched at some high
frequency so they are both visible at any sweep speed. This is, how-
ever, not appropriate for fast sweep speeds as the switching may
become visible and may interfere with the proper signal display.
28.4 ADD
In ADD mode the signals of both channels are algebraically added
and displayed as one sum signal. The Y-position can be changed
with both position controls. If one channel is inverted the diffe-
rence will be displayed. Only one ”0 V“ symbol will be shown in the
readout. The ADD mode will be indicated by placing a ”+“ symbol
between the sensitivity indications of both channels.
Please note that the results of cursor measurements in this
mode will only be correct if the sensitivities of both channels are
identical, otherwise the readout will show ”CH1
<>
CH2“.
Automatic voltage measurements can not be performed in ADD
mode. The readout will show ”n/a“ = not available.
As the trigger signals are taken off the inputs and not from the
added signal there is no true reference for the trigger point
symbol, the symbol will thus be switched off. However, the
LEVEL A/B control
15
is active.
28.5 XY-mode
In this mode CH1 will move the trace in X direction, hence the
readout will show ”CHX..“, CH2 will move the trace in Y direction,
hence ”CHY...“ will be shown rather than ”CH2...“.
As the time bases are not involved in XY no time base related
information will be shown. Also the trigger circuits are disabled
so no trigger information is shown, either.
The magnifi er MAG x10
25
is disabled. The ”0-Volt“ symbols
will be shown as triangles at the right hand graticule and above
the sensitivities.
Both knobs, the HORIZONTAL
23
or the POSITION 1
9
will
move the trace horizontally. The Y-position is controlled by the
POSITION 2 knob.
The CH1 signal can not be inverted
(if channel 1 was selected
for the X defl ection)
, there is hence no menu item in the CH1
menu (CH1 VAR pushbutton
27
). The TIME/DIV-VAR
24
knob is
disabled.
From serial number 049310019 (November 14th 2007), and
fi rmware version 05.300, a submenu is available for XY mode.
Pressing the “VERT/XY” pushbutton calls the “Vertical” menu
which contains the item “XY”. Pressing the “XY” function key
causes switchover to XY mode and simultaneously the display
of the “Vertical XY” submenu. It enables the selection of the
signal input (CH1 or AUX = AUXILIARY INPUT) to be used for X
defl ection, which is displayed in the menu under “X Channel”.
If CH1 is selected for X defl ection, “CH2” is automatically set as
the Y input which is displayed under “Y Channel”.
If “AUX” is chosen for X defl ection, “CH1”, “CH2” or “DUAL” (CH1
and CH2 simultaneously) can be used for Y defl ection.
28.6 Bandwidth Full/20 MHz
This pushbutton will select full or 20 MHz bandwidth.
– Full:
Full bandwidth will be the one given in the specifi cations.
– 20
MHz:
Provided measuring modes allow full bandwidth (i.e.
≥
5
mV/cm) this can be reduced to 20 MHz (–3 dB) in order to
attenuate high frequency noise e.g. The readout will show
BWL = bandwidth limited. The bandwidth limitation affects
both channels.
29
CH2 VAR
(pushbutton)
This pushbutton opens the CH2 menu which offers the
following options:
29.1 AC DC
The pushbutton will alternate between AC and DC coupling.
The readout shows a ”~“ or ”=“ symbol behind the sensitivity
indication.
29.1.1
DC coupling
The signal will be directly coupled to the input amplifi er via
the BNC connector
35
and the input attenuator. The input
resistance of the scope is a constant 1 MΩ irrespective of the
sensitivity selected.
29.1.2
AC coupling
A capacitor is inserted between the BNC connector and the at-
tenuator, thus the DC content of the signal is blocked and a high
pass with a lower cut-off frequency of approx. 2 Hz is created.
Low frequency signals will thus be more or less differentiated,
hence their shape and amplitude affected.
If the DC content of the signal changes, e.g. the duty cycle of
pulses, the capacitor must charge or discharge. This will cause
a momentary Y shift of the display.
