Subject to change without notice
16
Controls and Readout
setting will not be stored.
The
CHII
pushbutton can also be pressed simultaneously
with the
DUAL (17)
button. Please note item (17).
(21) TRIG. MODE
- Pushbuttons and indicator LEDs.
Pressing the upper or lower button selects the trigger
coupling. The actual setting is indicated by a
TRIG
.-LED
(18)
.
Each time the lower TRIG. MODE pushbutton is pressed
the trigger coupling changes in the sequence:
AC
DC content suppressed,
DC
peak value detection inactive,
HF
high-pass filter cuts off frequencies below
approx. 50kHz, trigger point symbol switched off
LF
low-pass filter cuts off frequencies above
approx. 1.5kHz,
TVL
TV signal, line pulse triggering,
trigger point symbol switched off,
TVF
TV signal, frame pulse triggering,
trigger point symbol switched off.
~
line/mains triggering, trigger point symbol
and
TRIG. LED (18)
are switched off.
In some trigger modes such as alternate triggering, some
trigger coupling modes are automatically disabled and
can not be selected.
(22) DEL.POS. - HO
rotary knob with two functions and related
HO
LED.
The
DEL.POS.
rotary knob functions as a Hold off time
control, when the time base is not working in the
SEA.
(SEARCH)
or in
DEL. (DELAY)
mode.
The
HO
-LED is not lit when the hold off time is set to
minimum. The
HO
LED lights up and the hold off time
increases as the knob is rotated clockwise. A signal
sounds on reaching the maximum hold off time. Similarly
in the opposite direction until minimum hold off time is
reached
(HO
LED extinguishes).
The hold off time is automatically set to minimum when
the time base is changed. (For the application of hold off
time setting see the paragraph with the same heading).
A delay time between the trigger event and the start of
the trace can be set with the
DEL.POS.
control in the
time base modes
SEA. (SEARCH)
or
DEL.(DELAY)
.
See
SEA./DEL.-ON/OFF (24).
(23)TIME/DIV.
The time base is set with this rotary knob in the
TIME/
DIV.
field, and the setting is displayed at the top left in
the Readout (e.g. ”T:10µs”).
This knob acts as the time base switch when the
VAR
LED above it is not lit. Then, the time deflection coefficient
can be set in a 1-2-5 sequence and the time base is
calibrated. Rotating anticlockwise increases the deflection
coefficient and rotating clockwise decreases the
deflection. The control acts as a vernier (fine adjustment)
when the
VAR
LED is lit.
The following description refers to the function as a time
base switch.
Time deflection coefficients between 500ms/div. and
50ns/div. in a 1-2-5 sequence can be selected without
x10 X magnification.
Time delay between 100ms and 100ns can be selected
in the
”SEA” (SEARCH)
mode.
Time deflection coefficient range in the
”DEL” (DELAY)
mode extends from 20ms/div. to 50ns/div.
(24) SEA./DEL. - ON/OFF
pushbutton.
This button is used to switch between delayed and
undelayed time base. The delayed time base operation
enables a magnified display in X direction which is
otherwise only possible with a second time base.
Pressing and holding the button switches to
SEA
.
(SEARCH)
mode, when currently neither
”SEA”
(SEARCH)
nor
”DEL” (DELAY)
operation is effective.
Afterwards, it can be switched between
SEA.
and
DEL.
by briefly pressing the button.
These operating modes are indicated in the Readout at
the right of the trigger slope indication thus:
In case of
SEARCH
,
”SEA”
will be displayed;
In untriggered
DELAY
mode,
”DEL” (DEL.)
and
in triggered
DELAY
mode,
”DTR” (DEL.TRIG.)
.
None of these will appear in the Readout in undelayed
time base operation.
When
”SEA”
,
”DEL”
or
”DTR”
mode is effective,
pressing and holding the button switches over to
undelayed time base.
The following description assumes that, with
x10 X-
MAG.
switched off, the trace starts at left edge of the
graticule.
In
SEA. (SEARCH)
mode, the hold off time is auto-
matically set to minimum and for the first few divisions
the trace is blanked. The trace will then be unblanked.
The point at which the trace starts can be varied with
DEL.POS
(fine adjustment) from about 2 to 7 divisions.
The blanked section serves as a guide to the delay time.
The delay time is based on the current time deflection
coefficient setting and can also be coarsely set with the
TIME/DIV
control (range: 20ms to 100ns).
Pressing the button briefly switches over from
”SEA”
to
DEL” (DELAY)
mode. Now the trace starts at the left
