32
Subject to change without notice
as variable which can change the sensitivity continuously
between 1 mV/cm to
>
20 V/cm. If in uncalibrated position, the
readout will replace ”:“ by ”
>
“ (e.g. ”CH1
>
5mV“.) and this also
in any cursor measurements pointing out that the sensitivity
is uncalibrated.
Pressing the “Variable On Off” function key again, switches
“Variable” off and the VOLTS/DIV VAR knob
12
back to calibrated
1-2-5 sequence defl ection coeffi cient function.
27.5 Probe
The menu display depends on whether the probe has dividing
ratio identifi cation. The value (automatically or manually selec-
ted) will be automatically taken into account regarding the
sensitivity indicated and measurements.
27.5.1
If a HAMEG probe with automatic dividing ratio identi-
fi cation is used, the menu display shows in normal intensity
“Probe” and beneath the dividing ratio (e.g. “*10”).
27.5.2
If no probe or a probe without automatic dividing ratio
identifi cation is used, the menu displays “Probe” and beneath
the last manually selected dividing ratio: the INTENS knob
2
symbol. Pressing the allocated function key causes “Probe” to
be displayed intensifi ed and the FOCUS TRACE MENU push-
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 (sensitivity,
inverted/not inverted, coupling and bandwith 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 (sensitivity,
inverted/not inverted, coupling and bandwith 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, ho-
wever, not appropriate for fast sweep speeds as the switching may
become visible and may interfere with the proper signal display.
26.7
A variable – On Off
If ”On“ was selected the TIME/DIV-VAR knob
24
will function
as variable control for the time base A speed. Only in time
base A only mode this option will be available in the menu.
For a full description see ”24.3 Variable“.
26.8
B variable – On Off
If ”On“ was selected the TIME/DIV-VAR knob
24
will function
as the time base B variable control. For a full description see
”24.3 Variable“.
26.9
HOLD OFF …%
In this mode the HOLD-OFF time may be selected from 0 to
100 % with the INTENS knob
2
. Values
>
0 extend the waiting
time after a sweep before a new one can start and decrease
thus the repetition rate which may darken the display. This is
indicated by the HOLD OFF-LED
21
lighting up. The HOLD-OFF
time is only valid for time base A.
Further information can be found in the section ”HOLD-OFF
adjustment“ in the chapter ”Triggering and time bases“.
27
CH1 VAR
(pushbutton)
This pushbutton opens the CH1 menu which contains the
following options referring to CH1
30
input respectively to the
signal on CH1.
27.1 AC DC
Pressing the pushbutton will switch from AC to DC or vice versa.
The mode selected will be shown in the readout following the
sensitivity setting: ~ is for AC and = is for DC.
27.1.1
DC coupling
The signal will be directly coupled, from the BNC connector via
the attenuator to the vertical amplifi er. The input resistance is
1 MΩ in all positions of the attenuator.
27.1.2
AC coupling
A capacitor is inserted between the BNC connector and the
attenuator, blocking the DC content of the signal and creating a
low frequency cut-off at approx. 2 Hz. This will affect the shape
and amplitude of signals with low frequency content. If the DC
content of the signal changes or the duty cycle of pulses the
capacitor will charge or discharge, this will cause a momentary
Y shift of the display.
27.2 Ground On Off
The pushbutton will either connect the amplifi er to the signal
or to ground. If set to Ground the readout will show a ground
symbol following the sensitivity setting, at the same place where
formerly the coupling was indicated. In the Ground position and
with automatic triggering a trace will be visible, this is handy for
setting the Y-position of it e.g. to the screen centre without dis-
connecting the signal. The readout will show a symbol ( ) for 0
V which will be close to the vertical centre line of the graticule, it
is the zero reference for any measurements. After switching back
to the signal its amplitude can now be determined with respect
to the formerly set zero reference.
27.3 Invert On Off
(unavailable in XY-mode)
This pushbutton will alternate between not inverted or inverted
of the CH1 signal. The readout will indicate an inverted display
by placing a bar above the CH1. The trigger signal derived from
CH1 will not be affected by an inversion.
27.4 Variable On Off
If activated (“On” intensifi ed) the CH1 VAR pushbutton
27
will
be illuminated and the VOLTS/DIV VAR knob
12
will function
C o n t r o l s a n d R e a d o u t
