43
Subject to change without notice
– 20
MHz:
Provided measuring modes allow full bandwidth (i.e.
≥
5mV/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
CH1 and pertains to analog and digital mode. In XY digital
mode the limitation is equal to Yt mode.
31.6 Offset On Off
(menu: page 2)
Under the condition “Offset On” is selected, the INTENS knob
2
can be used to adjust an internal offset voltage to offset
the input signal DC voltage. This is important if small low
frequency AC signals are measured which are superimposed
on relatively high DC voltages. The advantage is that DC
coupling now can be used to avoid signal distortion due to AC
coupling capacitor.
The offset voltage depends on the input attenuator (VOLTS/DIV –
SCALE-VAR) setting and is displayed by the readout. The previously
set offset voltage is present again when on is selected again.
31.7 Variable On Off
On condition “On“ the CH1 VAR pushbutton
31
is lit. Then the
VOLTS/DIV–SCALE–VAR knob
16
CH1 serves as variable control
that enables to change the defl ection coeffi cient continuously over
the complete range and consequently the signal display height.
If uncalibrated, a “
>
“ sign is displayed by the readout in front of
the defl ection coeffi cient; if calibrated a “:“ sign. The results of
voltage measurement are labeled in the same way.
After switching over from “Variable on“ to “Variable off“ with
the function key, the VOLTS/DIV–SCALE–VAR knob
16
returns
to 1-2-5 sequence switching and CH1 to calibrated condition.
32
VERT
/
XY
(pushbutton)
This pushbutton switches the ”vertical“ menu on/off. This
menu allows you to select the operating modes of the vertical
amplifiers.
32.1 CH1
If CH1 is selected only CH1 will be turned on, the mode can be
Yt or FFT. Also the readout will only display the parameters of
CH1. (sensitivity, inverted/not inverted, coupling and bandwidth
limiter.)
Although CH2 will not appear in the readout it may be used e.g.
as a trigger input with the exception of those modes in which
triggering is not possible (Roll, FFT, XY). Its controls are active
but are not shown.
32.2 CH2
If CH2 is selected only CH2 will be turned on, the mode can be
Yt or FFT. Also the readout will only display the parameters of
CH2. (sensitivity, inverted/not inverted, coupling and bandwidth
limiter.)
Although CH1 will not appear in the readout it may be used e.g.
as a trigger input with the exception of those modes in which
triggering is not possible (Roll, FFT, XY). Its controls are active
but are not shown.
32.3.1
DUAL trace alt./ chop
In dual trace mode both channels are turned on and the para-
meters of both are shown in the readout. Between the sensi-
tivity indications 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 unmagnified time
bases. Alternate is the preferred mode, at any time one channel
is displayed for a full sweep, after each sweep the other channel
has its turn. At slow sweep speeds this will cause annoying
flicker, 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, however, not appropriate for fast sweep
speeds as the switching may become visible and may interfere
with the proper signal display.
32.3.2
DUAL (digital mode).
In digital mode there is an A/D converter for each channel so
both are measured simultaneously. Hence no channel switching
is necessary and no information pertaining to it is shown.
FFT: DUAL, ADD and XY mode will not be offered in combination
with FFT.
32.4 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.
STOP
In digital mode ”1+2“ will be displayed at the end of
the trace.
Please note that the results of auto and 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 only be performed in
digital ADD mode. In analog ADD mode the readout will show
the voltage at the channel input chosen as the trigger source
(e.g. dc(Tr):...).
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 in ana-
log mode. However, the LEVEL A/B control
19
is active.
In digital mode a trigger time symbol is displayed one line
C o n t r o l s a n d R e a d o u t
VAR
VAR
VAR
x10
AUXILIARY INPUT
LC
0 ... LC3
LOGIC PROBE
Use recommended
probe only!
TRIG. EXT. / Z-INP.
LC/AUX
FFT
1M
Ω
II
15pF
max
100 Vp
INPUTS
1M
Ω
II15pF
max
250 Vp
X-INP
CH 1
VERT/XY
CH 2
HOR
MAG
CAT I
!
50
Ω
≤
5V RMS
50
Ω
≤
5V RMS
CH 1
CH 2
!
PROBE
ADJ
00
POWER
MENU
MENU
OFF
OFF
44
31
34
32
33
35
36
38
37
39
29
30
