Ch 1 - Led Button; Ch 2 - Led Button; Line - Led Button; Ext - Led Button - Rohde & Schwarz Hameg HM400 Manuel

F u n c t i o n o f t h e c o n t r o l s
e.g. 10 μs (/DIV). By activating the X-MAG / x10
further increased by a factor of 10 up to the maximum of 10 ns/DIV.
VAR: If the variable function was selected by pressing the knob shortly,
the time base speed can be reduced by turning it CCW and increased
by turning it CW, uncalibrated. Whenever the limits are reached, an
acoustic signal will be heard. By pressing the knob again, the function
variable can be left any time and calibrated operation resumed.
Hold-off time adjustment: Please rever to item
16 CH 1 – LED button
This button selects CH 1 as the trigger source. In all operating modes
of the vertical amplifi er except XY, CH 1 can be selected as the active
internal trigger source by pressing this button which will be indicated
by the LED lighting up.
INTERNAL TRIGGERING: The trigger signal is taken off
internally.
17 CH 2 – LED button
STOP
This button selects CH 2 as the trigger source. In all operating modes
of the vertical amplifi er except XY, CH 2 can be selected as the active
internal trigger source by pressing this button which will be indicated
by the LED lighting up.
18 LINE – LED button
This button selects the line (mains) as the trigger source. In all ope-
rating modes of the vertical amplifi er except XY the line (mains) can
be selected as the active trigger source which will be indicated by the
LED lighting up.
LINE TRIGGERING: The trigger signal is not derived from an
input signal but from the mains and taken from the power
supply.
19 STOP EXT – LED button
This button selects the external input as the trigger source. In all ope-
rating modes of the vertical amplifi er except XY pressing this button will
select the external BNC input EXT.TRIG/Z-INP
which will be indicated by the LED lighting up. The external Z-INP for
intensity modulation will be disabled.
EXTERNAL TRIGGER SOURCE: The trigger signal is not taken
from the measuring signals but from an external source.
20 AC – LED button
In all operating modes of the vertical amplifi er except XY pressing this STOP
button shortly will select AC trigger coupling which will be indicated
by the LED lighting up.
21 DC – LED button
In all operating modes of the vertical amplifi er except XY pressing this
button shortly will select DC trigger coupling which will be indicated by
the LED lighting up. The peak-to-peak detection will be disabled.
22 LF – LED button
In all operating modes of the vertical amplifi er except XY pressing this
button will insert a low pass fi lter (see the specifi cations) into the trigger
path which will be indicated by the LED lighting up. The low pass will
suppress high frequency interference which could disturb triggering.
23 TV – LED button
In all operating modes of the vertical amplifi er except XY pressing
this button shortly will activate the TV trigger separator which will be
indicated by the LED lighting up. The following remarks apply to the
PAL TV standard.
For frame synchronization the TIME/DIV
0.2 s/DIV and 1 ms/DIV, at 2 ms/DIV a full frame will be displayed.
38 Subject to change without notice
POWER
12 , the speed can be
27 .
31 as the trigger source
15 knob should be set between
18
14 14
VOLTS / DIV VOLTS / DIV
.2 .1 .2 .1
.5 .5
3 50 50
VAR
20
1 1
10
2 2
5 5 5
2
5 10 10
1 1
20 20
V mV V mV
6
DC DC
AC GND AC GND INV
CH 1 CH 2
X-INP INPUTS
1 MΩ II 15 pF
max.
400 V
p
!
CAT I
24 29 25 24 25 29 26
For line sycnhronization the TIME/DIV
0.5 ms/DIV and 0,1 μs/DIV. At 10 μs/DIV single lines can be displayed,
about 1 ½ lines will be visible.
24 DC/AC – LED buttons for CH 1 + CH2
By pressing these buttons shortly, the coupling of channel 1 or 2 resp.
can be alternated between DC and AC, the LED will light up if AC is
selected.
25 GND – LED buttons for CH 1 + CH2
By pressing these buttons shortly, the input of the channel 1 or 2
preamplifi er will be connected to ground resp., which will be indicated
by the LED lighting up. The signal present at the input BNC connector
can not infl uence the trace. In Yt-mode with auto trigger an undefl ected
trace will be visible (zero-volts trace position) .In XY-mode there will
be no defl ection in X and Y directions respectively.
26 INV – LED button for CH 2
By pressing this button shortly, the display of the channel 2 signal can
be alternated between normal and inverted. The LED will light up if
inversion is selected.
27 HOLD-OFF/ON – LED button
By shortly pressing this button, adjustment of the hold-off time by
turning the knob /TIME/DIV 15 will be activated which will be indicated
by the LED lighting up. Refer to item
function of this knob. The knob allows an increase of the hold-off time
from its minimum value by turning it CW, if the end of the range is
reached, an acoustic signal will be heard. Also, when the knob is turned
CCW, the acoustic signal will sound when the minimum value is reached.
As soon as the hold-off time adjustment is disabled by again pressing
, the hold-toff ime will be automatically reset to its minimum value. By
shortly pressing the TIME/DIV knob while
to alternate between setting the time/div. and hold-off time adjustment.
See also under „Hold-off time adjustment".
28 Z-INP – LED button
By shortly pressing this button, the function of the input EXT.TRIG /
Z-INP 31 is changed from external trigger input to external intensity
modulation input which will be indicated by the LED lighting up. If ex-
ternal triggering or the COMPONENT TESTER are selected, no intensity
modulation will be possible resp. it will be disabled. 0 V at the input will
not change the trace intensity, with 5 V TTL level the trace will be fully
suppressed, higher voltages are not allowed.
29 INPUT CH1 + CH2 – BNC connectors
These are the CH1 and CH2 inputs in Yt-mode and the X input in XY
mode. The ground of this connector is connected to the chassis and
thus to the mains safety earth. The buttons DC/AC
INV 26 (CH2 only) corresponf to this input.
16 20 22
15
17
19 21 23
TIME / DIV
.2
.1
TRIGGER
ms .5
50
VAR
20
1
20 CH 1 AC
10
2
10
5
CH 2 DC
10
5
20
1
2
LINE LF
.5
50
µs
.1s .2
.2s .1
EXT TV
HOLD
OFF
ON Z-INP
EXT. TRIG / Z-INP
1 MΩ II
15 pF
max.
PROBE ADJUST
100 V
p
1 kHz / 1 MHz
ca. 0.2 Vpp
30 31
27 28
15 knob should be set between
15 for information about the triple
27 is activated, it is possible
24 , GND 25
5
2
27
and